ACCEPTANCE TESTINGVerification that is conducted to determine whether a release satisfies its acceptance criteria and that provides the government with information for determining whether the release should be accepted. Acceptance testing also applies to toolkits, science algorithm integration, and unit-level verification of cots products.

ACCOUNTABILITY MANAGEMENT DATA Information collected about the utilization of ecs services by individual users for the purposes of accountability, e.g., An audit trail of data access or service requests.

ACCOUNTING MANAGEMENT DATA Information collected about the utilization of ecs resources and attributed to specific accounts (e.G., Users). This information is forwarded by sdps to mss for accounting and billing purposes. The information includes request identifier, date and time of request, media cost, cpu utilization, i/o utilization, personnel costs, shipping and handling costs, networking costs, and archival costs, as applicable.

ACKNOWLEDGMENT A message sent to the sender of a service request, for the purpose of informing the sender that the service request was received and accepted by its intended recipient.

ACTIVE DATA BASE SITE. A general designation for a site where data are being used actively in research and from which those data and resident expertise may be obtained. Source: ESADS.

ACTIVE LONG TERM ARCHIVE (ALTA). A facility that provides permanent active archive functions for EOSDIS Archived Holdings (see below) during and beyond the scope of the EOS mission, receiving responsibility for these holdings and providing long-term access to users. An ALTA is funded independently of the EOS budget. ALTAs include the NASA/National Space Science Data Center (NSSDC), the USGS/Earth Resources Observation System (EROS) data center, and the NOAA/National Environmental Satellite, Data, and Information Service (NESDIS) data centers. Source: EPO.

ACTIVE PLAN The plan which is currently used by production processing.

ACTIVITY A specified amount of scheduled work that has a defined start date, takes a specific amount of time to complete, and comprises definable tasks.

ADVERTISEMENT A text description that announces the availability of an eosdis data set, data product, and/or associated ecs service(s).

ADVERTISEMENT REQUEST A request for information contained in an advertisement which is uniquely identified by the request.

ADVERTISING SERVICE Through the advertising service, users can search and query descriptions of the data and services available in the network. This data is called advertisements. It is prepared by the data and/or service providers.

AEROMETER An instrument for ascertaining the weight or density of air and gases

AEROSOL. A gaseous suspension of fine particles. Source: EPO.

AFFILIATED DATA CENTER (ADC) A facility not funded by nasa that processes, archives, and distributes earth science data useful for global change research, with which a working agreement has been negotiated by the eos program. The agreement provides for the establishment of the degree of connectivity and interoperability between eosdis and the adc needed to meet the specific data access requirements involved in a manner consistent and compatible with eosdis services. Such data-related services to be provided to eosdis by the adc can vary considerably for each specific case.

AFFORESTATION The act or process of establishing a forest, especially on land not previously forested. Source: EPO.

AGGREGATION A special form of association, between a whole and its parts, in which the whole is composed of the parts.

ALBEDO The fraction of the total solar radiation incident on a body that is reflected by it. Source: EPO.

ALGORITHM Software delivered to the sdps by a science investigator (principal investigator, team leader, or ii) to be used as the primary tool in the generation of science products. The term includes executable code, source code, job control scripts, as well as documentation.

ALGORITHM UPDATES Algorithm updates are delivered to the pgs's integration and test environment by scientists at a science computing facility. They represent changes to existing production algorithms, or a new algorithm to produce a new standard product. Algorithm updates include the source code for the candidate algorithm, its associated documentation, and a job step control skeleton. The source code will be compiled to form an executable program suite as part of the integration and test process. The job step control skeleton contains instructions that control the sequence of execution of, and the interchange of data between programs from the executable program suite. Test data sets and calibration data should also be included.

ALIAS Another name; in this context, aliases provide alternate names to be used for datasets to account for varying references from one community to another

ALLOCATED BASELINE The detailed technical description that allocates all segment/element functional characteristics to hwcis and cscis. This baseline is initially established at pdr and refined and expanded into detailed designs at cdr. The allocated baseline for ecs releases subsequent to release a is built upon the product baseline for the previous release.

ALTIMETER An instrument for taking altitudes geometrically

ANALYSIS Technical or mathematical evaluation based on calculation, interpolation, or other analytical methods. Analysis involves the processing of accumulated data obtained from other verification methods.

ANCILLARY DATA Data other than instrument data required to perform an instrument's data processing. They include orbit data, attitude data, time information, spacecraft engineering data, calibration data, data quality information, and data from other instruments.

ANNUAL MEAN In this context, usually refers to a product which calculates a set of mean values for all geophysical parameters generated by a given data production algorithm over the course of a year.

ARCHITECTURAL UNIT A generic term for any of the following: system, segment, element, subsystem, hwci, csci, csc, or csu.

ARCHIVED HOLDINGS All EOS and non-EOS data and data products, as well as supporting information, that are archived by EOSDIS. This includes models, algorithms, documentation, and level 0 data or higher level data products from which level 0 may be recovered. Source: EPO.

ASCII FILE A data file whose contents are encoded as ascii characters.

ASSOCIATION A relationship among instances of two of more classes describing a group of links with common structure and common semantics

ATMOSPHERE The envelope of gases surrounding the Earth and bound to it by the Earth's gravitational attraction. Studies of the chemical and radiative properties, dynamic motions, and physical processes of this system constitute the field of meteorology. Source: EPO.

ATTITUDE DATA Data that represent spacecraft orientation and onboard pointing information. Attitude data includes:

* attitude sensor data used to determine the pointing of the spacecraft axes, calibration and alignment data, euler angles or quaternions, rates and biases, and associated parameters.

* attitude generated onboard in quaternion or euler angle form.

* refined and routine production data related to the accuracy or knowledge of the attitude.

ATTITUDE SENSOR DATA Attitude sensor data is that subset of the telemetry data that is used to determine the pointing of the spacecraft axes, calibration and alignment data, Euler angles or quaternions, rates and biases, and associated parameters.

ATTRIBUTE A named property of a class describing a data value held by each object of the class

AUTHORIZED USER Any user of ecs who has obtained authorization from the system to access certain restricted files or other parts of the system.

AUTHORIZED WORK Work that has been definitized and is on contract, plus work that has been authorized but is not yet definitized.

AUXILIARY DATA Auxiliary data can be any data set which enhances the processing or utilization of satellite remote sensing instrument data. The auxiliary data is not captured by the same data collection process as the instrument data. Auxiliary data sets can include data collected by any platform or process, preferably in georeferenced digital format (ceos).

AVAILABILITY A measure of the degree to which an item is in an operable and committable state at the start of a "mission" (a requirement to perform its function) when the "mission" is called for an unknown (random) time. (mathematically, operational availability is defined as the mean time between failures divided by the sum of the mean time between failures and the mean down time [before restoration of function].

AVAILABILITY (INHERENT) (AI) The probability that, when under stated conditions in an ideal support environment without consideration for preventive action, a system will operate satisfactorily at any time. The "ideal support environment" referred to, exists when the stipulated tools, parts, skilled work force manuals, support equipment and other support items required are available. Inherent availability excludes whatever ready time, preventive maintenance downtime, supply downtime and administrative downtime may require. Ai can be expressed by the following formula:

ai = Mtbf/ (mtbf + mttr)

Where: Mtbf = mean time between failures

Mttr = mean time to repair

AVAILABILITY (OPERATIONAL) (AO) The probability that a system or equipment, when used under stated conditions in an actual operational environment, will operate satisfactorily when called upon. Ao can be expressed by the following formula:

Ao = ^{Mtbm / ( mtbm + mdt + st )}

Where: Mtbm = mean time between maintenance (either corrective or preventive)

Mdt = mean maintenance down time where Corrective, preventive administrative and logistics Actions are all considered.

St = standby time (or switch over time)

AVERAGING Standard data averaging involves extraction from a data granule of aggregate pixels formed by numerically averaging the n adjacent pixels in each of one or more dimensions of the granule. The number of pixels in each dimension to be averaged is characterized by the value of "n."

BAND, SPECTRAL 1) a predefined partition of the electromagnetic spectrum, which establishes the wavelength boundaries to be measured. 2) a selection of wavelengths 3) frequency band 4) absorption band

BAROMETER An instrument for measuring the weight or pressure of the atmosphere, and hence for judging of probable changes in the weather, ascertaining the height of an ascent, etc.

BASELINE (1) Identification and control of the configuration of software (i.E. Selected software work products and their descriptions) at given points in time.

BASELINE (2) Performance is measured. It is comprised of time phased cost account budgets, undistributed budgets, and indirect budgets. Management reserve is not a part of the pmb.

BASELINE ACTIVITY PROFILE A schedule of activities for a target week corresponding to normal instrument operations constructed by integrating long term plans (i.E., Ltsp, ltip, and long term spacecraft operations plan).

BASELINE CHANGE CONTROL The system used to establish, analyze, communicate, and record approved changes to the program baseline.

BASELINE, CONFIGURATION MANAGEMENT SPECIFIC A configuration identification document or a set of such documents formally designated by the government at a specific time during a configuration item's life cycle. Baselines, plus approved changes from those baselines, constitute the current approved configuration identification.

BIBLIOGRAPHIC REFERENCE PAPERS A record of the use of data products, documentation on the generating algorithms, and other reference material.

BINARY FILE A data file whose contents are in binary form (i.E., Not encoded).

BIOLOGICAL PRODUCTIVITY The amount of organic matter, carbon, or energy content that is accumulated during a given time period. Source: EPO.

BIOMASS The total dry organic matter or stored energy content of living organisms that is present at a specific time in a defined unit (community, ecosystem, crop, etc.) of the Earth's surface. Source: EPO.

BIOSPHERE The portion of Earth and its atmosphere that can support life. The part (reservoir) of the global carbon cycle that includes living organisms (plants and animals) and life-derived organic matter (litter, detritus). The terrestrial biosphere includes the living biota (plants and animals) and the litter and soil organic matter on land; the marine biosphere includes the biota and detritus in the oceans. Source: EPO.

BROWSE A representation of a dataset or data granule used to pre-screen data as an aid to selection prior to ordering. A data set, typically of limited size and resolution, created to rapidly provide an understanding of the type and quality of available full resolution data sets. It may also enable the selection of intervals for further processing or analysis of physical events. For example, a browse image might be a reduced resolution version of a single channel from a multi-channel instrument. Note: Full resolution data sets may be browsed. Source: SPSO, ESADS.

BROWSE DATA Browse data is a subset of a larger data set, other than the directory and guide, generated for the purpose of allowing rapid interrogation (i.E., Browse) of the larger data set by a potential user. For example, the browse product for an image data set with multiple spectral bands and moderate spatial resolution might be an image in two spectral channels, at a degraded spatial resolution. The form of browse data is generally unique for each type of data set and depends on the nature of the data and the criteria used for data selection within the relevant scientific disciplines

BROWSE DATA PRODUCT Subsets of a larger data set, other than the directory and guide, generated for the purpose of allowing rapid interrogation (i.E., Browse) of the larger data set by a potential user. For example, the browse product for an image data set with multiple spectral bands and moderate spatial resolution might be an image in two spectral channels, at a degraded spatial resolution. The form of browse data is generally unique for each type of data set and depends on the nature of the data and the criteria used for data selection within the relevant scientific disciplines.

BROWSE PRODUCT A granule or collection of granules which serve as a predefined, reduced resolution aid to ordering of one or more full resolution ecs granules.

BROWSE REQUEST A request for browse data.

BUDGET CHANGE REQUEST The document used to record changes to work breakdown structure elements that affect the scope of work, budget, and/or schedule at that specified level.

BUDGET/SCHEDULE CHANGE REQUEST The document used to record changes to wbs elements that affect the scope of work, budget, and/or schedule at that specified level.

BUILD An assemblage of threads to produce a gradual buildup of system capabilities.

BUILD, CONFIGURATION MANAGEMENT SPECIFIC An assemblage of threads to produce a gradual buildup of system capabilities. Builds are combined with other builds and threads to produce higher level guilds.

CALIBRATION The collection of data required to perform calibration of the instrument science data, instrument engineering data, and the spacecraft engineering data. It includes pre-flight calibration measurements, in-flight calibrator measurements, calibration equation coefficients derived from calibration software routines, and ground truth data that are to be used in the data calibration processing routine.

CALIBRATION DATA Calibration data is the collection of data required to perform calibration of the instrument science data, instrument engineering data, and the spacecraft engineering data. It includes pre-flight calibration measurements, in-flight calibrator measurements, calibration equation coefficients derived from calibration software routines, and ground truth data that are to be used in the data calibration processing routine.

CAMPAIGN A coordinated, relatively short-term data collection effort which is conducted as a subset of time or region of an experiment's or project's data collection activity. E.G., One summer's worth of data for a time series that covers sequential summers for comparison.

CANCELLATION REQUEST A cancellation request is a service request that directs a server to terminate the execution of a service request.

CANDIDATE PLAN A production plan which is not currently used in production, but can be used as input to a plan activation request.

CAPABILITIES AND REQUIREMENTS REVIEW (CRR) Assessment of eosdis annual project-level capabilities and requirements. Crr is conducted to determine if ecs is meeting its objectives and provides evolutionary direction for new or modified requirements. Current information is provided on how ecs supports the eos mission.

CAPTIVE ACCOUNT A guest's user account in a computer system for any user to access without special procedures (such as registration). The account puts the user directly into an application, without access to the rest of the system on which the application is hosted. ESDIS IMS Lexicon.

CARBON CYCLE All parts (reservoirs) and fluxes of carbon; usually thought of as a series of the four main reservoirs of carbon interconnected by pathways of exchange. The four reservoirs regions of the Earth in which carbon behaves in a systematic manner are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels). Each of these global reservoirs may be subdivided into smaller pools ranging in size from individual communities or ecosystems to the total of all living organisms (biota). Carbon exchanges from reservoir to reservoir by various chemical, physical, geological, and biological processes. Source: EPO.

CAST A technique for acquiring sea surface or near surface measurements, by dropping an instrument from the side of a cruise vessel

CATALOG INTEROPERABILITY Refers to the capability of the user interface software of one data set directory or catalog to interact with the user interface at another data set directory or catalog. Three levels of catalog interoperability are recognized:

* level 1 interoperability - simple network interconnectivity among systems.

* level 2 interoperability - catalog systems can exchange limited search and user information.

* level 3 interoperability - catalog systems exchange standard search protocols. This provides "virtual" similarity between different systems.

CATALOG SERVICE A set of information, consisting of some or all of directory, guide, and inventories, combined with a mechanism to provide responses to queries, possibly including ordering data. Source: ESADS.

CATALOG SYSTEM An implementation of a directory, plus a guide and/or inventories, integrated with user support mechanisms that provide data access and answers to inquiries. Capabilities may include browsing, data searches, and placing and taking orders. The system is a specific implementation of a catalog service.

CHANNEL A preset electromagnetic wavelength to be measured within a band.

CHLOROFLUOROCARBONS A family of inert, nontoxic, and easily liquefied chemicals used in refrigeration, air conditioning, packaging, and insulation, or as solvents or aerosol propellants. Because they are not destroyed in the lower atmosphere, they drift into the upper atmosphere, where, given suitable conditions, their chlorine components destroy ozone. Source: EPO.

CLASS I CHANGE Changes that impact ecs project-level milestones, budget, costs, and requirements. Class i changes may not be implemented until approved by the earth science data and information system (esdis) change control board.

CLASS II CHANGE Engineering changes which are not defined as class i changes (e.G. Changes in documentation to correct errors or add clarifying notes).

CLASS, OBJECT A description of a group of objects with similar properties, common behavior, common relationships, and common semantics

CLIENT Entity that wishes to invoke an operations on a target object via the object request broker.

CLIMATE The statistical collection and representation of the weather conditions for a specified area during a specified time interval, usually decades, together with a description of the state of the external system or boundary conditions. The properties that characterize the climate are thermal (temperatures of the surface air, water, land, and ice), kinetic (wind and ocean currents, together with associated vertical motions and the motions of air masses, humidity, cloudiness and cloud water content, groundwater, lake winds, and water content of snow on land and sea ice), and static (pressure and density of the atmosphere and ocean, composition of the dry air, salinity of the oceans, and the geometric boundaries and physical constants of the system). These properties are interconnected by various physical processes such as precipitation, evaporation, infrared radiation, convection, advection, and turbulence. Source: EPO.

CLIMATE CHANGE The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate. External processes, such as solar-irradiance variations, variations of the Earth's orbital parameters (eccentricity, precession, and inclination), lithosphere motions, and volcanic activity, are factors in climatic variation. Internal variations of the climate system, e.g., changes in the abundance of greenhouse gases, also may produce fluctuations of sufficient magnitude and variability to explain observed climate change through the feedback processes interrelating the components of the climate system. Source: EPO.

CLOSE REQUEST A close request is a service request that directs a dim, lim, or data server to terminate a client session and thereby deallocate resources used to support the processing of service requests for that session.

CLOUD A visible mass of condensed water vapor particles or ice suspended above the Earth's surface. Clouds may be classified by their visual appearance, height, or form. Source: EPO.

CLOUD ALBEDO Reflectivity that varies from less than 10 to more than 90 percent of the insolation and depends on drop sizes, liquid water content, water vapor content, thickness of the cloud, and the sun's zenith angle. The smaller the drops and the greater the liquid water content, the greater the cloud albedo, if all other factors are the same. Source: EPO.

CLOUD FEEDBACK The coupling between cloudiness and surface air temperature in which a change in surface temperature could lead to a change in clouds, which could then amplify or diminish the initial temperature perturbation. For example, an increase in surface air temperature could increase the evaporation; this in turn might increase the extent of cloud cover. Increased cloud cover would reduce the solar radiation reaching the Earth's surface, thereby lowering the surface temperature. This is an example of negative feedback and does not include the effects of longwave radiation or the advection in the oceans and the atmosphere, which must also be considered in the overall relationship of the climate system. Source: EPO.

CO-INVESTIGATOR An individual selected by the Principal Investigator who typically provides support in preparing the proposal and who has specific responsibilities in the development, operations, or analysis phases of the investigation. Source: ESADS.

CODE ANALYSIS Static/dynamic code checking for memory leaks, argument list mismatches, code coverage, and other coding errors.

CODING GUIDELINE Recommended, but not required, programming style.

CODING STANDARD Required programming style.

COLLOCATED Physically located in the same institution.

COLOR TABLE Table mapping pixel values to colors.

COMMAND Instruction for action to be carried out by a space-based instrument or spacecraft.

COMMAND AND DATA HANDLING (C&DH) The spacecraft command and data handling subsystem which conveys commands to the spacecraft and research instruments, collects and formats spacecraft and instrument data, generates time and frequency references for subsystems and instruments, and collects and distributes ancillary data.

COMMAND GROUP A logical set of one or more commands which are not stored onboard the spacecraft and instruments for delayed execution, but are executed immediately upon reaching their destination on board. For the u.S. Spacecraft, from the perspective of the eos operations center (eoc), a preplanned command group is preprocessed by, and stored at, the eoc in preparation for later uplink. A real-time command group is unplanned in the sense that it is not preprocessed and stored by the eoc.

COMMANDING Process of scheduling and issuing instructions for actions to be carried out by a space-based instrument or spacecraft. Source: EPO.

COMMERCIAL INSTRUMENT An instrument developed and operated by a private organization whose data are sold commercially to the general user community. Source: ESADS.

COMMERCIAL OFF-THE-SHELF (COTS) Cots is a product, such as an item, material, software, component, subsystem, or system, sold or traded to the general public in the course of normal business operations at prices based on established catalog or market prices.

COMMUNITY CONSENSUS ALGORITHM The current global algorithm or spatial mosaic of algorithms for a Pathfinder data product, as agreed upon by a Pathfinder Science Working Group. Source: EPO.

COMPONENT The next lower functional subdivision below "subsystem" in the ecs functional hierarchy.

COMPREHENSIVE AND INCREMENTAL SCHEDULING Two modes of scheduling. Comprehensive scheduling is the automatic scheduling of a full set of events. Incremental scheduling is interactive scheduling of selected events. For example, the initial generation of a schedule might use comprehensive scheduling, while the addition of a single event with the desire to avoid perturbing previously scheduled events might use incremental scheduling.

COMPUTER PROGRAM LIBRARY (CPL) A library designated to establish and maintain software in media form. The computer program library handles, stores, and manages master magnetic media and related data.

COMPUTER SOFTWARE COMPONENT (CSC) A distinct part of a computer software configuration item. Cscs may be further decomposed into other cscs and computer software units.

COMPUTER SOFTWARE CONFIGURATION ITEM (CSCI)

A configuration item comprised of computer software components and computer software units.

COMPUTER SOFTWARE UNIT (CSU) An element specified in the design of a csc that is separately testable. A package of work allocated to an individual member of the software development team (csus do not span personnel boundaries).

CONFIGURATION
CHANGE CONTROL Configuration change control is the systematic coordination, evaluation, and release of approved changes to an established baseline.

CONFIGURATION
CONTROL The systematic proposal, justification, evaluation, coordination, approval or disapproval of proposed changes, and the implementation of all approved changes in the configuration of a configuration item after formal establishment of its baseline.

CONFIGURATION The functional and physical characteristics of hardware, firmware, software or a combination thereof as set forth in technical document and achieved in a product.

CONFIGURATION CHANGE REQUEST (CCR) A document that requests and justifies a change to a configuration item.

CONFIGURATION ITEM, CONFIGURATION MANAGEMENT SPECIFIC An aggregation of hardware, firmware, software or any of its discrete portions, which satisfies an end use function and is designated for configuration control. Cis are those items whose performance parameters and physical characteristics must be separately defined (specified) and controlled to provide management insight needed to achieve the overall end use function and performance.

CONFIGURATION MANAGEMENT DATA Information which relates specific versions of individual software, data and hardware items to each other (i.E., Defining a configuration of such items), and information which describes changes to such configurations.

CONFIGURATION MANAGEMENT TOOL Software tool for doing automated configuration management of source code, scripts, documentation, and other computer files.

CONFLICT ADJUDICATION REQUEST A conflict adjudication request is a message sent to the smc requesting that the smc resolve a processing conflict between the sdsrv ci, the science user, and the data processing subsystem.

CONFLICT ADJUDICATION RESPONSE A conflict adjudication response is a message sent by the smc describing the resolution of a processing conflict specified by a conflict adjudication request. A conflict adjudication response contains the following information:

A. Conflict adjudication request identification

B. Data type

C. Priority modifications

D. Account balance modifications

E. Information on when request will be serviced

F. Smc contact point

CONSENT TO SHIP REVIEW (CSR) Review to determine the readiness of a release for transition to sites for integration testing.

CONTINUOUS OPERATION The ability to support continuous data collection by the reliable, repetitive, systematic observation of the Earth features appropriate to the measurement being made. For EOS, continuous operation will allow the entire globe to be monitored not less than once on the day side and once on the night side every 16 days. Source: EPO.

CONTRACTOR-ACQUIRED PROPERTY Property acquired or otherwise provided by the contractor for performing a contract and to which the government has title.

CONTRACTUAL MILESTONES Specific delivery or event dates specified in the contract. These dates may not be changed in the schedules without customer approval through a contract change.

CONTROL MILESTONES Any event that the project manager and/or the government considers critical. Control milestones include contract and project office specified milestones. They cannot be revised or slipped without approval by the project manager and, if applicable by the government.

COORDINATED UNIVERSAL TIME Also known as utc, the equivalent of greenwich mean time, a single time relevant to any point on the globe, and from which all other time zones originate.

CORE The central portion of the Earth, at a depth of approximately 2900 km. The core has a molten metallic composition. Source: EPO.

CORE INVENTORY METADATA Core inventory metadata is metadata that is available for all ecs standard data products.

CORRELATIVE DATA Scientific data from other sources used in the interpretation or validation of instrument data products, e.G., Ground truth data and/or data products of other instruments. These data are not utilized for processing instrument data.

COST ACCOUNT A management control level at which actual costs are normally collected and compared to earned value. A cost account is a natural control point for cost/schedule planning and control because it represents the work assigned to one responsible organizational element for one element of the work breakdown structure.

COST ACCOUNT MANAGER (CAM) Usually a member of first-level project management who is responsible for a unit or segment of work and has the appropriate authority level for planning, performing and controlling that work.

COVERAGE MAP The footprint coverage of a remote sensing sensor projected on a surface (i.e. A graphical representation of the coverage of data or a granule located on the Earth. Source: ESDIS IMS Lexicon.

CPU TIME Elapsed time spent by a processor doing some task, not counting idle time (as opposed to wall clock time, which includes idle time).

CRITICAL DESIGN REVIEW (CDR) A detailed review of the element/segment-level design, including such details as program design language for key software modules, and element interfaces associated with a release.

CRITICAL PATH A path on a network which has the greatest negative slack and is the longest path in time through the network.

CROSS TRACK Relative to the collection of measurements by an instrument or sensor aboard a satellite that orbits the earth; refers to the capture of measurements from left to right and/or right to left as the satellite moves along its orbital track.

DAAC See distributed active archive center

DAAC AI&T ENVIRONMENT The hardware (processing platforms, other workstations, etc.) And software (compilers, linkers, diagnostic tools, etc.) Used to integrate and test the science software at the daac.

DAAC AI&T STAFF The personnel actually involved in doing the integration and test of the science software at the daac. This includes daac personnel, scf developers who are helping with ai&t, etc.

DAAC ENGINEERING
LIAISON Systems engineer responsible for bi-directional flow of information between the daac and ecs. Responsible engineer for ensuring daac lessons learned are properly incorporated in ecs design and development. Responsible engineer for ensuring the daac is current on ecs architecture.

DAAC SCIENCE
LIAISON The ecs daac scientists are located at the eosdis daacs. They provide a working level interface between the ecs development and daac science advisory groups, daac user communities, and daac scientific staffs. The objectives are to facilitate understanding, by the ecs developers, of the scientific data needs of the daac user communities and to foster daac and science community involvement in the ecs requirements definition and development process.

DAAC-UNIQUE Functions and capabilities provided by the daac beyond those provided by the core system. The functions will be integrated with ecs via apis for other similar mechanisms. Examples of daac-unique functions include visualization, specialized interfaces, and data set-unique functionality.

DAILY AVERAGE In this context, usually refers to a product which calculates a set of average values for all geophysical parameters generated by a given data production algorithm over the course of a day.

DAR DISPOSITION Dar disposition is information that is a notification of the confirmation, rejection, scheduling, or completion of a data acquisition request, and includes at a minimum:

A. Date and time

B. Instrument identifier

C. Dar identifier

D. Dar status

E. Implementation schedule

F. Reason for rejection (if applicable)

DATA Data is the output of an ecs service, and includes data products, subsets of data products, data granules, search results, browse images, and the output of processing requests.

DATA ACCESS PRIVILEGE Information which specifies which types of accesses (i.E., Read, update, insert, delete) a user is allowed for any given type of data.

DATA ACQUISITION REQUEST A data acquisition request (dar) is a service request that specifies the collection of data associated with a specified instrument or instruments. A dar contains the following information at a minimum:

DATA ACQUISITION REQUEST (CONTINUED 1) A. Observation number

B. Experimenter identification

C. Experimenter address

D. Investigation identification

E. Scientific discipline

F. Observation repetition period

DATA ACQUISITION REQUEST(CONTINUED 2) N. Minimum coverage required

O. Maximum coverage desired

P. Number of instruments involved in the investigation.

Q. Which instruments are involved in the investigation.

DATA ARCHIVE A facility providing indefinitely long storage, preservation, disposition, and distribution of data sets and associated metadata. Source: ESADS.

DATA ARCHIVE AND DISTRIBUTION SYSTEM

(DADS)

Included in each daac and responsible for archiving and distribution of eos data and information.

DATA AVAILABILITY SCHEDULE Data availability schedule is a schedule indicating the times at which specific data sets will be available from remote dads, edos, the international partners, the adcs, and other data centers for ingestion by the collocated dads. The schedules are received directly by the pgs.

DATA CENTER A facility storing, maintaining, and making available data sets for expected use in ongoing and/or future activities. Data centers provide selection and replication of data and needed documentation and, often, the generation of user tailored data products.

DATA DESTINATION Data destination is information that describes where data is to be transmitted electronically.

DATA DICTIONARY
CONTEXTS A method for organizing information in the data dictionary from a user perspective. For example, atmospheric dynamics could be defined as a data dictionary context. Search and access requests to the data dictionary can reference a context and thus restrict the visibility of data dictionary information to that context.

DATA DICTIONARY
VIEWS A method for preselecting a subset of the data dictionary information for the purpose of access. For example, a view might select only the attributes which correspond to product directory information.

DATA DICTIONARY A data dictionary is a repository of descriptive information about data. Data dictionary information includes database elements and valid values used to describe datasets. Source: ESDIS IMS Lexicon.

DATA DICTIONARY DOMAINS A method for organizing data dictionary information from a provider perspective. The domain of a data dictionary could be a distributed information manager, a specific site (i.E., A local information manager), or a data server.

DATA DICTIONARY INFORMATION Provides explanations for the various ecs data types, their data elements, the operations available on these data types, explanations of abbreviations used by the values of such data elements, and lists of valid values of data elements.

DATA FORMAT Data format contains the following information, where applicable:

A. Units conversion specification

B. Compression format specification

DATA GRANULE The smallest aggregation of data that is independently managed (i.E., Described, inventoried, retrievable). Granules may be managed as logical granules and/or physical granules.

DATA IDENTIFIER A data identifier is information that uniquely identifies data to be manipulated by an ecs service.

DATA INSERT REQUEST A data insert request is a service request that calls for the storage of data or metadata into a data server.

DATA ITEM(S) Value(s) of a measured or derived parameter, implicitly or explicitly accompanied by an identification of the points in independent variable space where the value(s) applies (e.g., x,y,z,t;a,b,c). Source: ESADS.

DATA PROCESSING REQUEST A data processing request is a service request passed to the processing ci to initiate the processing of a pge. The request provides the processing ci information about 1 specific production job. The data processing request will contain information used to execute a pge. This information includes priority, user parameters, input data, output data, and resource information, etc.

DATA PRODUCT A collection (1 or more) of parameters packaged with associated ancillary and labeling data. Uniformly processed and formatted. Typically uniform temporal and spatial resolution. (Often the collection of data distributed by a data center or subsetted by a data center for distribution.) Source: SPSO There are two types of data products: Standard - A data product produced at a DAAC by a community consensus algorithm. Typically produced for a wide community. May be produced routinely or on-demand. If produced routinely, typically produced over most or all of the available independent variable space. If produced on-demand, produced only on request from users for particular research needs typically over a limited range of independent variable space. Source: SPSO. Special - A data product produced at a Science Computing Facility by a research status algorithm. May migrate to a community consensus algorithm at a latter point. If adequate community interest, may be archived and distributed by a DAAC. Source: ESDIS

DATA PRODUCT A set of one or more outputs of a product generation executive.

DATA PRODUCT LEVELS * raw data--data in their original packets, as received from the observer, unprocessed by edos.

* level 0--raw instrument data at original resolution, time ordered, with duplicate packets removed.

* level 1a--reconstructed unprocessed instrument data at full resolution, time referenced, and annotated with ancillary information, including radiometric and geometric calibration coefficients and georeferencing parameters (i.E. Platform ephemeris) computed and appended, but not applied to level 0 data.

DATA PRODUCT LEVELS (CONTINUED) * level 1b--radiometrically corrected and geolocated level 1a data that have been processed to sensor units.

* level 2--derived geophysical parameters at the same resolution and location as the level 1 data.

* level 3--geophysical parameters that have been spatially and/or temporally re-sampled (i.E., Derived from level 1 or level 2 data).

* level 4--model output and/or results of lower level data that are not directly derived by the instruments.

Data levels 1 through 4 as defined in the eos data panel report. Consistent with the committee on data management and computation and earth science and applications data system definitions.

DATA PRODUCTS See

"special data product"

And

"standard data product"

DATA PYRAMID A method for representing the multi-layered aspects of earth science and related data. The various levels of the pyramid are intended to correspond to various levels of abstraction, aggregation, or synthesis of data, and the narrowing towards the top is meant to reflect the generally decreasing amounts of data at each layer. Although the types of data at the various layers do not always adhere to these general rules, the pyramid has nevertheless proven to be an effective tool for presenting the multi-layers nature of earth science and related data.

DATA QUALITY REQUEST Data quality request is a request issued by the pgs to a scientist at a science computing facility to perform qa of a particular product before future processing or distribution. A time window is applied to the request in keeping with the production schedule.

DATA RATE PROFILE Instrument's and subsystem's data rate requirements (e.G., Recorder data rate) to be included in the instrument or subsystem resource profiles.

DATA RECEIPT LOG Alias for "ingest history log."

DATA REQUEST A data request is a service request that directs sdps to stage and/or distribute specified data. The specification of the data may direct sdps to perform processing (e.G., Subsetting) on the data prior to its final staging or distribution. The most trivial example of a data request is a service request that requests the distribution of a specified data product. There are two kinds of data requests, staging requests and distribution requests. Data requests contain the following information:

A. User identifier

B. Request priority

C. Data type

D. Data identifier(s)

DATA REQUEST (CONTINUED) E. Processing instructions (e.G., Subsetting instructions), if
Applicable

F. Suggested earliest start time

G latest completion time.

H. Distribution instructions or staging instructions (as
Applicable)

DATA REQUEST STATUS Information describing the either the current progress of an ongoing data request or the outcome of a completed data request. The data request status contains the following information

A. User identifier

B. Request identifier

C. Request state

D. If rejection, then the reason for the rejection.

E. Adjusted start and completion times if request was delayed
Longer than latest completion time specified by user.

F. Distribution status (if the data request was a distribution
Request)

DATA RIGHTS An agreement between the funding agent, the project, and the investigation team whereby the team is accorded exclusive use of data for a limited period of time. Source: ESADS.

DATA SERVER Either the data server subsystem as a whole, or a specific instance of a data server. A data server is a (hardware/ software) entity which accepts, stores, and distributes eos (and other) data, for both other subsystems within ecs and external users.

DATA SET A logical collection of data products for which the producer has defined an advertisement.

DATA SET CATALOG See CATALOG INTEROPERABILITY.

DATA SET DIRECTORY See DIRECTORY.

DATA SET DOCUMENTATION Information describing the characteristics of a data set and its

Component granules, including format, source instrumentation, calibration, processing, algorithms, etc.

DATA TYPE (1) A particular type of data handled by a particular data server. An example of a data type might be modis level 1a products, etc.

DATA TYPE (2) Sdps uses a scheme for classifying data into types. A preliminary list of ecs data types is contained in the sdps database design / schema specification (did 311).

DATA TYPE IDENTIFIER Identifier of the data type (e.G., Cer001).

DATA TYPE TAXONOMY A classification of earth science and related data into types.

DATA USER GUIDE A document, either on-line or hardcopy, containing the necessary information for the correct usage of the data. Source: ESADS.

DATA VISUALIZATION The ability to examine a data file as a raw data dump, a plot, or an image.

DATABASE (1) A collection of data sets with supporting metadata related to a system, project or facility. (2) A collection of integrated data serviced by a Data Base Management System (DBMS); often organized for quick search and retrieval. Source: ESAD.

DATABASE TRANSACTION A series of database queries which are bracketed by a start transaction and end transaction command. Programmers use database transactions to group a set of related database queries which should either all be executed, or not at all executed. For example, in case of a failure during execution of a transaction, the queries which already completed should be rolled back.

DEEP SPACE NETWORK (DSN) The network of NASA ground stations normally used to communicate with deep space probes or high- altitude satellites. The DSN can provide backup communications with low Earth-orbiting satellites. Source: EPO.

DEFINITIVE ORBIT DATA Definitive orbit data is spacecraft orbit data computed by the fdf based on tracking data from tdrss satellites or ground stations, and spans a time interval that corresponds to the tracking data interval.

DEFORESTATION The removal of forest stands by cutting and burning to provide land for agricultural purposes, residential or industrial building sites, roads, etc., or by harvesting the trees for building materials or fuel. Oxidation of organic matter releases CO2 to the atmosphere, and regional and global impacts may result. Source: EPO.

DELIVERED ALGORITHM PACKAGES The full content of data and information delivered by a data producer during the process of standard product algorithm integration & test, including all elements defined as minimum content within volume 4 of the science user's guide, available at pdr.

DELIVERY RECORD File containing information describing data to be ingested. It has the same structure as network ingest request.

DEMONSTRATION (DEMO) Observation of the functional operation of the verification item in a controlled environment to yield qualitative results without the use of elaborate instrumentation, procedure, or special test equipment.

DEPENDENT VALID VALUES Dependent valid values are parameter values that describe the acceptable values that a user may specify for a given parameter and are dependent on information that the user has already specified.

DESIGN INTERFACE The interaction and relationship of logistics with the system engineering process to ensure that system element influences the definition and design of system elements so as to reduce life cycle costs.

DESKTOP OBJECTS A subclass of general desktop objects used in the design of the desktop for the sdps client subsystem. Distinguishing capabilities include: the ability to associate programs with each type and instance of the class, e.G., To display, manipulate, or edit the object; and the notion that the object may have complex structure, i.E., Consists of parts which themselves may be document objects. Although derived from research work related to traditional documents, a desktop document object can be any kind of complex data object, for example, an hierarchical data format file.

DETAIL SCHEDULES Schedules used by the cams to manage their scope of work on the project. An example of a detail schedule is a schedule of all work packages within a cost account. This schedule may consist of a network, a collection of activities or a combination of both.

DETAILED ACTIVITY SCHEDULES The schedule for a spacecraft and instruments which covers up to a10 day period and is generated/updated daily based on the instrument activity listing for each of the instruments on the respective spacecraft. For a spacecraft and instrument schedule the spacecraft subsystem activity specifications needed for routine spacecraft maintenance and/or for supporting instruments activities are incorporated in the detailed activity schedule.

DETECTORS The electromechanical device which registers some predefined radiance measurement; in this context, an instrument usually is comprised of a set of detectors, each of which collects its preestablished measurement values.

DEVIATION A written request to depart temporarily (for a specific period of time or number of units) from the authorized baseline requirements (i.E., A temporary or limited waiver).

DIRECT BROADCAST Continuous down-link transmission of selected real-time data over a broad area (non-specific users).

DIRECTIVES Directives consist of information received by the pgs from the system management center that acts as a final authoritative directive for action. It may include general policies, official procedures, and resolutions of schedule conflicts that have not been resolved with the ims.

DIRECTORY A collection of uniform descriptions that summarize the contents of a large number of data sets. It provides information suitable for making an initial determination of the existence and contents of each data set. Each directory entry contains brief data set information (e.G., Type of data, data set name, time and location bounds).

DIRECTORY SERVICE A directory, possibly supplemented with other kinds of information, combined with a mechanism to provide responses to queries. Source: ESADS.

DIRECTORY SYSTEM A specific implementation of a directory service. Source: ESADS.

DISCIPLINE A field of study (e.G. Oceanography, meteorology, geology, land biology).

DISK SPACE USAGE The amount of disk space that a process requires to run. This includes in particular the amount of space required to read and write any input, intermediate, or output data files.

DISTRIBUTED ACTIVE ARCHIVE CENTER (DAAC) An eosdis facility which generates, archives, and distributes eos standard products and related information for the duration of the eos mission. An eosdis daac is managed by an institution such as a nasa field center or a university, per agreement with nasa. Each daac contains functional elements for processing data (the pgs), for archiving and disseminating data (the dads), and for user support and information management (elements of the ims).

Asf -- alaska sar facility

Edc -- eros data center

Gsfc -- goddard space flight center

Jpl -- jet propulsion laboratory

Larc -- langley research center

Msfc -- marshall space flight center

Nsidc -- national snow and ice data center

DISTRIBUTED QUERY PLAN A distributed query plan is an organized set of search requests formulated by the distributed information manager for the purpose of executing a search request involving multiple sites. Each search request within the distributed query plan is intended to be processed at a single site by either a lim (i.E., A site search request) or a single data server.

DISTRIBUTED SEARCH REQUEST A distributed search request is a search request that is processed by a dim and requires data and services from multiple sites.

DISTRIBUTION FAILURE MESSAGE A distribution failure message is information that is logged to the distribution activity log when a distribution request fails validation. It contains the following information:

A. User identifier

B. Request identifier

C. Date and time

D. Reason for failure

DISTRIBUTION INSTRUCTIONS Distribution instructions is information contained in a distribution request that specifies how data is to be distributed. An electronic distribution request contains distribution instructions consisting of the following:

A. Data format

B. Push-pull flag

C. Data destination

DISTRIBUTION REQUEST A distribution request is a data request that directs sdps to distribute specified data electronically, or via the shipment of hard media. The specified data can be data that is permanently stored or generated on-demand, or it can be staged data that is temporarily stored in a user-accessible staging area. Staged data can be a data product or data generated as the result of processing performed by a previous service request. See data request, for the format of a distribution request.

DISTRIBUTION REQUEST STATUS (see data request status)

DISTRIBUTION STATUS Information describing the amount of data written to media or transmitted electronically, during the processing of a distribution request.

DISTRIBUTION STATUS REQUEST A distribution status request is a status request that requests the status of a distribution request (see status request)

DOCUMENT INGEST REQUEST A document ingest request is an ingest request that directs sdps to automatically transfer document data into the sdps from an external data provider. The document ingest request contains the following information:

A. External data provider;

B. Date/time prior to which the data will remain available;

C. Requested ingest priority;

D. List of data type identifiers;

E. For each data type identifier: a list of document file
Identifiers; the corresponding file volumes; the document title;
The document author; and a list of document search keywords.

DOMAIN The set of legal values for an attribute in a database

DYNAMIC BROWSE Refers to the generation of a browse product, including subsetting and/or resampling of data, by command of the user engaged in the browse activity. The browse data set is built in real-time, or near-real-time, as part of the browse activity.

DYNAMIC DATA SETS Dynamic data sets are those containing parameters whose values change routinely and predictably; i.E. At set intervals in time.

DYNAMIC VALIDS The logical and valid combinations of keywords formed from various categories of valids (e.g. source, sensor, parameter) that can be used to express a valid query. The subset of the valids for a particular keyword which remain applicable given previously entered criteria. For example, once a platform has been entered, only the sensors which were actually on that platform would be valid for entry. Source: ESDIS IMS Lexicon.

EARNED VALUE (1) The amount of work accomplished for a task regardless of time or budget spent.

EARNED VALUE (2) The sum of the values for accomplished work plus the appropriate portion of the values for level of effort and apportioned effort. On c/scsc projects, this is the budgeted cost for work performed.

ECS CONTRACTOR
TEAM Hughes applied information system

Arc (applied research corporation)

Eds (electronic data systems corporation)

Essi (engineering & science services inc.

Htsc (hughes technical services corporation)

Loral aerosys

Nyma inc.

ECS EVOLUTIONARY DEVELOPMENT The process for delivering and evolving ecs functionality through the used of multiple development tracks and delivery mechanisms. Use of development tracks and delivery mechanisms are tailored to the goals of the particular portion of the system of the system, with an overall goal of providing relatively stable portions of the system in comparison to portions which are rapidly adapting to the system's environment.

ECS PROJECT Ecs provides single-point access for a worldwide science community, simultaneous mission management for multiple instruments, and regular production of validated science products using community-supplied algorithms.

ECS-SUPPORTED A hardware or software component that conforms to an earth science data and information system (esdis) approved set of standards and has been fully tested by the ecs contractor.

EDGE ENHANCEMENT A feature enhancement technique which enhances the display of outlines of objects in an image.

EDOS QUICK LOOK PRODUCTION DATA
SETS Data sets generated by edos using raw instrument or spacecraft packets from a single tracking and data relay satellite system (tdrss) acquisition session and made available for delivery to a user within 1 hour of receipt of the last packet in the session. Transmission artifacts are removed, but time ordering and duplicate packet removal is limited to packets received during the tdrss contact period.

ELECTRONIC DISTRIBUTION REQUEST An electronic distribution request is a distribution request that directs sdps to distribute specified data electronically. See data request, for the format of an electronic distribution request.

ELECTRONIC MAIL The ability to send and receive messages across the internet.

ELEMENT The next lower functional subdivision below "segment" within the ecs functional hierarchy.

ELEMENT TEST REVIEW (ETR) Determines if development level testing (for each release) has successfully been completed.

EMERGENCY FIX A change installed and documented in controlled hardware or software with the responsible change control board's (or designated representative's) approval, but separate from a formally released change.

ENGINEERING DATA (1) All data available on-board about health, safety, environment, or status of the spacecraft and instruments.

* housekeeping data: the subset of engineering data required for mission and science operations. These include health and safety, ephemeris, and other required environmental parameters.

* instrument engineering data: all non-science data provided by the instrument.

* platform engineering data: the subset of engineering data from platform sensor measurements and on-board computations.

* spacecraft engineering data: the subset of engineering data from spacecraft sensor measurements and on-board computations.

ENGINEERING DATA (2) Measurements transmitted from an instrument which reflect the status and conditions of the instrument and/or platform

ENVIRONMENTAL MONITORING AND OPERATIONAL USE Includes data use by those government agencies affiliated with the parties which conduct environmental monitoring and/or operational observations for the public good, and can include larger agencies to which the parties belong (i.e., the World Meteorological Organization); or national agencies, or their designates, involved in other operational forecasting activities which are conducted for the public good (i.e., weather, sea state, sea ice, agriculture, hydrology, etc.). Environmental Monitoring and Operational Use of Data constitutes any use of data to carry out a mandate of environmental observation and prediction as part of an agency's responsibilities to provide for the general welfare. Such use may include the routine downlink or direct broadcast of enhanced and unenhanced data in near-real time within the operational community.

EOS COMMUNICATIONS (ECOM) The ground-based EOS subsystem interface between Earth-orbiting satellites and TDRSS. It provides forward link connectivity between the SN and the DSN and EOSDIS. It provides for command links through TDRSS, data capture and production processing of telemetry, processing raw data to Level 0, and archiving Level 0 data. Source: EPO.

EOS DATA AND INFORMATION SYSTEM (EOSDIS) A facility that will manage the data resulting from NASA's Earth science research satellites and field measurement programs, and other data essential for the interpretation of these measurements. It will also provide access to data held in the archives of other government agencies, organizations, and countries. EOSDIS will generate user-defined data products, and will facilitate the combination and manipulation of data from all sources as well as their incorporation into models of the environment. Concomitant to fulfilling its data management functions, EOSDIS will encourage interdisciplinary research and assist in breaking down the intellectual barriers between the traditional disciplines of Earth science by offering an integrated view of environmental data. Source: EPO.

EOS DATA AND OPERATIONS SYSTEM

(EDOS) PRODUCTION DATA SET Data sets generated by edos using raw instrument or spacecraft packets with space-to-ground transmission artifacts removed, in time order, with duplicate data removed, and with quality/ accounting (q/a) metadata appended. Time span, number of packets, or number of orbits encompassed in a single data set are specified by the recipient of the data. These data sets are equivalent to level 0 data formatted with q/a metadata.

For eos, the data sets are composed of: instrument science packets, instrument engineering packets, spacecraft housekeeping packets, or onboard ancillary packets with quality and accounting information from each individual packet and the data set itself and with essential formatting information for unambiguous identification and subsequent processing.

EOS DATA PRODUCTS Three primary categories of EOS mission data products that will be provided by EOSDIS have been defined, as follows: Source: EPO. Prototype Data Products. Generated as part of a research investigation, of wide research utility, requiring too much data or computer power for generation at the investigator SCF, and accepted as a candidate Standard Data Product by the IWG. Prototype Data Products will be generated at DAACs, but their routine generation is not guaranteed and will not interfere with Standard Data Product generation. Special Data Products. Generated as part of a research investigation using EOS data and produced for a limited region or time period, or products that are not accepted as standard by the IWG and NASA Headquarters. They will be generated at research users' computer facilities. Standard Data Products. Generated as part of a research investigation, of wide research utility, accepted by the IWG and the EOS Program Office, routinely produced, and, in general, spatially and/or temporally extensive data products. Standard Level 1 data products will be generated for all EOS instruments; standard Level 2 data products will be generated for most EOS instruments. Some EOS interdisciplinary investigations will also generate standard data products.

EOS OPERATIONS CENTER (EOC) The facility responsible for EOS mission operations, including command and control of EOS spacecraft, mission planning and scheduling, and coordination of EOS instrument planning and scheduling. All commands for EOS spacecraft and instruments go through the EOC for integration and validation before transmission to space. Source: EPO.

EOS PROGRAM The activity that provides the long-term observations and the supporting information system necessary to develop a comprehensive understanding of the way the Earth functions as a natural system. The EOS Program Office and the EOS Project are included in the EOS Program. Source: EPO.

EOS PROGRAM DIRECTOR The NASA Headquarters official who is the focal point for all Headquarters activities bearing on the EOS Program. Source: EPO.

EOS PROGRAM OFFICE The EOS Program Director and his staff. The EOS Program Office is located at NASA Headquarters. Source: EPO.

EOS PROGRAM SCIENTIST The NASA Headquarters official assigned to the EOS mission. The roles and responsibilities of this function are defined in NMI 7100.11, Attachment D. One of them is to establish the policies for the analysis, dissemination, and archiving of data for the mission. Source: EPO.

EOS PROJECT The EOS Project Manager, his staff, and all other participants in the EOS Program who are located at GSFC. Source: EPO.

EOS PROJECT MANAGER The GSFC official who has overall responsibility for executing to completion the design, development, test and operation of the EOS Program within a given set of boundary conditions (technical, cost, schedule, and organization approach). The senior individuals in subordinate installations may also be titled Project Managers, but they are responsible to the GSFC Project Manager. Source: EPO.

EOS PROJECT SCIENTIST The NASA field center or U.S. academic institution scientist assigned to the EOS mission to manage its scientific aspects. The roles and responsibilities of this function are given in NMI 7100.11, Attachment E. Source: EPO.

EPHEMERIS A tabular statement of the spatial coordinates of a celestial body or a spacecraft as a function of time. Source: EPO.

EPHEMERIS DATA See "orbit data"

ESSENTIAL DATA PRODUCT A data product that has major significance to the EOS Program and its science users. The EOS Program considers successful production of such data products essential and will use such production as a measure of performance. Source: EPO.

EVALUATION PACKAGE An evaluation package is a delivery mechanism for incrementally developed components and selected prototypes. The objectives of evaluation packages are to increase user involvement in system evolution and rapid evaluation and to facilitate rapid incorporation of user feedback into the incremental development process.

FACILITY INSTRUMENT An instrument defined by nasa as having broad significance to the eos program and provided by a designated nasa center or foreign agency.

FAULT MANAGEMENT DATA Information describing system faults, such as hardware and operating system failures and application software errors which is forwarded by sdps to mss upon detection of the fault. The information includes type of fault, date and time fault, and identification of the failing system component.

FEATURE ENHANCEMENT Various techniques for enhancing the display of an image so that certain types of features are more easily seen.

FEDERATED SCHEMA A schema for distributed data repositories which is constructed from the schema for each repository in a simple manner (called federating), usually as a union.

FEEDBACK MECHANISMS A sequence of interactions in which the final interaction influences the original one. Source: EPO.

FIELD CAMPAIGN An activity set up to collect science data at a given site in the field; a campaign is usually limited in time, and may be repeated over the course of several months or years as part of broader project goals. The data collected will usually be stored within ecs as ground truth data, providing a calibration and validation source for the remotely sensed data.

FLIGHT HARDWARE All active mission hardware in orbit about the Earth. For EOS, flight hardware includes all EOS spacecraft and EOS instruments on International Platforms and other spacecraft. Source: EPO.

FORMAL DEVELOPMENT TRACK A development process distinguished by complete tree of requirements documentation, formal reviews at major milestones in the development cycle and a single waterfall of phases leading to a formal release. The single waterfall has a long time frame relative to the incremental development track and prototypes.

FORMAL QUALIFICATION TESTING A process that allows the contracting agency to determine whether a configuration item complies with the allocated requirements for that item.

FORMAL RELEASE A formal release (release) is a system-wide update to the ecs, delivered and tested as a part of the eosdis. Ecs releases will represent the ecs portion of eosdis versions. Formal releases are part of the formal development track.

FORMAT Format of data -- ascii, binary, etc.

FORWARD LINK DATA Instrument control and spacecraft control data. Source: EPO.

FOSSIL FUEL Any hydrocarbon deposit that can be burned for heat or power, such as petroleum, coal, and natural gas. Source: EPO.

FUNCTION The action or actions which an item is designed to perform.

FUNCTIONAL BASELINE The initial baseline established at srr and refined at sdr.

FUNCTIONAL CONFIGURATION AUDIT (FCA)

The formal examination of functional characteristics of a ci, prior to acceptance, to verify that the item has achieved the performance specified in its functional or allocated configuration identification.

GENERALIZATION The relationship between a class and one or more refined or specialized versions of it.

GEOGRAPHIC LOCATION The spatial area of coverage by a granule, usually specified as one of a fixed set of pre-determined regions, or "global".

GLOBAL Modifier which can denote total or nearly total coverage of the Earth, land, ocean or both. Global can also be a qualifier to describe the distribution of a particular phenomenon over the earth although coverage isn't literally global. E.g. Global land would be all land over the earth but land certainly doesn't entirely cover the globe.

GOVERNMENT FURNISHED EQUIPMENT (GFE) Gfe is equipment either furnished to a contractor, as in government-furnished equipment, or acquired by the contractor, as in contractor-acquired equipment.

GOVERNMENT FURNISHED INFORMATION Government furnished information are specific, non-tangible items of data supplied by the government to the contractor necessary to achieve contractor performance requirements. Gfi items include a delivery time requirement. Examples of gfi include answers to questions, promulgation of policy, scientific datasets and science algorithms, and spacecraft data bases, etc.

GOVERNMENT FURNISHED PROPERTY (GFP) Gfp is property in the possession of or directly acquired by the government and subsequently made available to the contractor

GRANULE The smallest aggregation of data that is independently managed (i.E., Described, inventoried, retrievable). Granules may be managed as logical granules and/or physical granules.

GRANULE LOCATION The name of the product where this granule is located.

GREENHOUSE GASES Those gases, such as water vapor, carbon dioxide, tropospheric ozone, nitrous oxide, methane, and CFCs, that are largely transparent to solar radiation but opaque to outgoing long wave radiation. Their action is similar to that of glass in a greenhouse. Some of the long wave (infrared) radiation is absorbed and reemitted by the greenhouse gases. The effect of this is to warm the surface and the lower atmosphere of the earth. Source: EPO.

GREGORIAN CALENDAR The modification of the julian calendar, adapted to bring it into closer conformity with astronomical data, and the natural course of the seasons, and to rectify already contracted by its use, introduced by pope gregory xiii in a.D. 1582, and adopted by great britain in 1752.

GROUND NETWORK The network of ground stations that support near- Earth spacecraft primarily in the launch or early mission phase. The Ground Network is the successor to the NASA Satellite Tracking and Data Acquisition Network (STADAN). Source: EPO.

GROUND TRUTH Geophysical parameter data, measured or collected by other means than by the instrument itself, used as correlative or calibration data for that instrument data. It includes data taken on the ground or in the atmosphere. Ground truth data are another measurement of the phenomenon of interest; they are not necessarily more "true" or more accurate than the instrument data.

GUIDE A detailed description of a number of data sets and related entities, containing information suitable for making a determination of the nature of each data set and its potential usefulness for a specific application.

GUIDE SERVICE A set of detailed information combined with a mechanism to provide responses to queries. Source: ESDIS IMS Lexicon.

GUIDE SYSTEM A specific implemented mechanism that provides guide information in response to queries. Source: ESDIS IMS Lexicon.

HARD MEDIA INGEST REQUEST A hard media ingest request is an ingest request that directs sdps to transfer data into the sdps from hard media, as provided by an external data provider. The hard media ingest request contains the following information:

A. User identifier for the external data provider;

B. Media type; and

C. List of one or more hard media identifiers

HARD METRIC The use of rational metric units as the basis of measurement rather than mathematically converted inch-pound units. Source: EPO.

HARDWARE That combination of subcontracted, cots, and government furnished equipment (e.G., Cables and computing machines) that are the platforms for software.

HARDWARE CONFIGURATION ITEM

(HWCI)

A configuration item comprised of hardware components.

HDF FILE A data file whose format follows the ncsa hierarchical data format standard, as well as ecs-developed extensions thereto.

HERITAGE Relative to production heritage, the history of all processing characteristics of a product, which are retained to support accurate recreation of the processing environment during reprocessing; relative to heritage data, that which ecs will be ingesting from existing archives, as opposed to that which ecs will be producing as part of standard or special processing.

HOUSEKEEPING DATA The subset of engineering data required for mission and science operations. These include health and safety, ephemeris, and other required environmental parameters.

I/O ACCESS A read or write by a process to a data file.

IMMEDIATE COMMAND Command issued to an instrument or subsystem that is transmitted with minimum delay for immediate execution. Delay would be due only to non-availability of uplink and/or the actual time to transmit the command.

IN OPERATIONS (OR OPERATIONAL) An ecs capability is in operations if some of the following are true:

* it is accessible by non-ecs personnel (no matter how restricted the group may be)

* some or all of it resides outside of the ecs development facility

* it is used to support outside agencies/projects (including testing of interfaces with such)

Operations does not necessarily imply responsibility of the formal m&o organization. For example, the early eps are operated by a combination of the ecs developers and the site liaisons.

IN-SITU DATA Data measurements gathered at a particular ground-based site, which will be used in ecs as calibration or validation of the remotely sensed data.

INCREMENTAL DESIGN REVIEW Review conducted to evaluate segment designs associated with a release.

INCREMENTAL DESIGN REVIEW (IDR) Review conducted to evaluate segment designs associated with a release.

INCREMENTAL DEVELOPMENT TRACK A development process distinguished by multiple iterations of requirements, design, and implementation with frequent user evaluations via demonstrations. Documentation and reviews are streamlined. Documentation of non-mission critical is created after development has completed. Each increment is developed with the potential of being integrated into the formal track for a release. The incremental development track has a cycle time between the formal development and prototypes.

INCREMENTAL SCHEDULING See "comprehensive and incremental scheduling.

INDEPENDENT VERIFICATION AND VALIDATION (IV&V) Verification and validation performed by a contractor or government agency that is not responsible for developing the product or performing the activity being evaluated. Iv&v is an activity that is conducted separately from the software development activities governed by the ecs contract.

INFORMATION MANAGEMENT SYSTEM (IMS) The user interface for EOSDIS. It provides information about data, both in EOSDIS and in external archives, on a 24-hour basis; accepts user orders for EOS data; provides information about future data acquisition and processing schedules; accepts and forwards data acquisition and processing requests; and maintains information on system status, management, and coordination. Source: EPO.

INFRARED RADIATION Electromagnetic radiation lying in the wavelength interval from 0.7 5m to 1000 5m (micrometers). Its lower limit is bounded by visible radiation, and its upper limit by microwave radiation. Most of the energy emitted by the Earth and its atmosphere is at infrared wavelengths. Infrared radiation is generated almost entirely by large-scale intramolecular processes. The tri-atomic gases, such as water vapor, carbon dioxide, and ozone, absorb infrared radiation and play important roles in the propagation of infrared radiation in the atmosphere. Source: EPO.

INGEST ERROR LOG Log containing errors and other status occurring during ingest request processing.

INGEST HISTORY LOG The ingest history log contains information associated with a completed ingest request. An alias for ingest history log is "data receipt log."

INGEST REQUEST An ingest request is a service request that directs sdps to ingest data into the sdps from an external data provider.

INSPECTION The visual, manual examination of the verification item and comparison to the applicable requirement or other compliance documentation, such as engineering drawings.

INSTANCE One snapshot occurrence of a particular object class, with its own unique set of values of the class's attributes, distinguishing it from all other instances.

INSTITUTIONAL FACILITIES OR
INSTITUTIONAL
ELEMENTS Facilities established by an institution that take on some responsibility in support of eosdis, or elements of the eosdis that function as part of an institution, and represent both eosdis and the programs, goals and purpose of the institution.

INSTRUMENT * a hardware system that collects scientific or operational data.

* hardware-integrated collection of one or more sensors contributing data of one type to an investigation.

* an integrated collection of hardware containing one or more sensors and associated controls designed to produce data on/in an observational environment.

INSTRUMENT ACTIVITY DEVIATION LIST An instrument's activity deviations from an existing

Instrument activity list, used by the eoc for developing the detailed activity schedule.

INSTRUMENT ACTIVITY LIST An instrument's list of activities that nominally covers seven days, used by the eoc for developing the detailed activity schedule.

INSTRUMENT CONTROL CENTER (ICC) An EOS facility dedicated to a specific instrument that plans and schedules instrument operations, generates and validates command sequences, provides the capability to forward commands and to store them for later transmission, monitors the health and safety of the instrument, and provides instrument controllers with status information of their instrument. Source: EPO.

INSTRUMENT CONTROL FACILITY (ICF) A facility containing one or more EOS ICCs. Source: EPO.

INSTRUMENT DATA Instrument data is data specifically associated with an instrument, either because the data was generated by the instrument or included in data packets identified with that instrument. Instrument data consists of instrument science data and engineering data, and possible ancillary data

INSTRUMENT ENGINEERING DATA

Subset of telemetered engineering data required for performing instrument operations and science processing

INSTRUMENT MICROPROCESSOR MEMORY LOADS Storage of data into the contents of the memory of an instrument's microprocessor, if applicable. These loads could include microprocessor-stored tables, microprocessor-stored commands, or updates to microprocessor software.

INSTRUMENT RESOURCE DEVIATION LIST An instrument's anticipated resource deviations from an

Existing resource profile, used by the eoc for establishing tdrss contact times and building the preliminary resource schedule.

INSTRUMENT RESOURCE DEVIATION LIST An instrument's anticipated resource deviations from an

Existing resource profile, used by the eoc for establishing tdrss contact times and building the preliminary resource schedule.

INSTRUMENT RESOURCE PROFILE Anticipated resource needs for an instrument over a target

Week, used by the eoc for establishing tdrss contact times and building the preliminary resource schedule.

INSTRUMENT SCIENCE DATA Data produced by the science sensor(s) of an instrument, usually constituting the mission of that instrument.

INTEGRATED LOGISTICS SUPPORT (ILS) The disciplined, unified, and iterative approach to management, engineering and technical activities necessary to plan and direct support considerations into every aspect of system development and operation. Regardless of organizational assignment or functional allocation, the discipline of ils is the integration of multiple technical disciplines that address the support aspects of a system. The integration of all system elements is necessary to provide support at minimum life cycle costs.

INTEGRATED SCHEMA A schema for distributed data repositories which presents the data of these repositories as a single, integrated database. The schema may define new concepts, such as new, 'virtual data products' which are derived from the underlying data in the repositories in a possibly complex fashion. A mapping between the integrated schema and those of the individual repositories describes the derivations. The mapping can be quite complex - whereas a federated schema has a very simple mapping, e.G., 1-to-1.

INTEGRATION The orderly progression of combining lower level software and/or hardware items to form higher level items with broader capability.

INTEGRATION AND TEST LOG An ongoing record of integration and test activities.

INTERDISCIPLINARY INVESTIGATOR COMPUTING FACILITIES (IICF)

Project-provided facilities at interdisciplinary investigator locations used to pursue eos-approved investigations and produce higher-level data sets.

INTERFACE CLASSES The interfaces offered by a class of objects or object collections. User, for example, in the context of service classes to denote the collection of interfaces supported by this service class.

INTERFACE DEFINITION LANGUAGE (IDL)

Idl provides uniform semantics for all interfaces.

INTERFACE MILESTONES These milestones that represent the delivery of hardware, software or documents between organizational elements within the ecs project. The "hard" interface milestones, defined as hardware or software movement between organizations will always be included and will also generally include the significant "soft" interfaces between organizations, defined as the "paper" interfaces. They are often referred to as handshakes between organizations.

INTERFACE(S) The functional and physical characteristics required to exist at a common boundary.

INTERIM RELEASE The delivery of system capability resulting from early efforts on the formal track development to the customer for testing of eos functionality prior to an operational version.

INTERMEDIATE LOGIC NETWORK Schedules at the build-thread level that show major activities, milestones, events and interface milestones. The iln is organized by release.

INTERMEDIATE SCHEDULES Summary level bar chart schedules that show major activity spans, events, and interdependency milestones at the release, subsystem, or major organizational levels.

INTERNATIONAL PARTNERS Signatories of the Space Station MOUs that established the initial funding for the International Polar Platforms program to monitor Global Change, including NASA, ESA, Japan, and Canada. Source: EPO.

INTERNET A collection of government, educational, and commercial networks which cooperate to allow data transfer between their users. The internet evolved out of an experimental dod network called arpanet.

INTEROPERABILITY Refers to the capability of the user interface software of one data set directory or catalog to interact with the user interface at another data set directory or catalog. Three levels of catalog interoperability are recognized:

* level 1 - simple network interconnectivity among systems.

* level 2 - catalog systems can exchange limited search and

User information.

* level 3 - catalog systems exchange standard search protocols.

this provides "virtual" similarity between different systems.

INVENTORY (1) A uniform set of descriptions of granules from one or more data sets with information required to select and obtain a subset of those granules. Granule descriptions typically include temporal and spatial coverage, status indicators, and physical storage information. An inventory may describe physical granules, logical granules, or both, including a mapping between them if they are not identical.

Note that the inventory is not the granules themselves, but rather the descriptive data for each of them, specifically used by both system and user to locate those desired.

INVENTORY (2) The collection of data granule specific information which describes the individual data granules managed by a data server.

INVENTORY CHARACTERIZATION Enhanced content-based metadata describing granules or aggregations of granules (phenomenology data bases, super-granules, feature tags, etc.)

INVENTORY SERVICE An inventory, possibly supplemented with other kinds of information, combined with a mechanism to provide responses to queries, possibly including ordering data. Source: ESDIS IMS Lexicon.

INVENTORY SYSTEM A specific implementation of an inventory service. Source: ESADS.

INVESTIGATOR

SEE ALSO "SCIENTIST" An individual who is contracted to conduct a specific scientific investigation. (an instrument pi is the person designated by the eos program as ultimately responsible for the delivery and performance of standard data products derived from an eos instrument investigation.)

INVESTIGATOR WORKING GROUP (IWG) A group made up of the principal investigators and research instrument team leaders associated with the instruments on a single spacecraft. The iwg defines the specific observing programs and data collection priorities for a single spacecraft based on the guidelines from the iwg.

IONOSPHERE Rarefied, ionized region of the Earth's atmosphere, between approximately 60 and 400 km. Source: EPO.

JULIAN CALENDAR That introduced by julius ceasar b.C. 46, in which the ordinary year has 365 days and every fourth year is a leap year of 366 days, the months having the name, order and length still retained.

LAND CRYOSPHERE Snow and ice coverage over land

LEVEL 0 DATA Level 0 data is raw instrument data at original resolution, time ordered, with duplicate packets removed.

LEVEL 1A DATA Level 1a data is level 0 data which may have been reformatted or transformed reversibly, located to a coordinate system, and packaged with needed ancillary and engineering data.

LEVEL 1B DATA Level 1b data is radiometrically corrected and calibrated data in physical units at full instrument resolution as acquired.

LEVEL 2 DATA Level 2 data are environmental variables retrieved from level 1 data (e.G., Ocean wave height, soil moisture, ice concentration) at the same location and similar resolution as the level 1 source data.

LEVEL 3 DATA Level 3 data is data or retrieved environmental variables that have been spatially and/or temporally resampled (i.E., Derived from level 1 or level 2 data products). Such resampling may include averaging and compositing.

LEVEL 4 DATA Level 4 data is model output and/or variables derived from lower level data which are not directly measured by the instruments. For example, new variables based upon a time series of level 2 or level 3 data

LEVEL OF EFFORT
(LOE) Effort that cannot be associated with a definable end product or result. Loe is planned and earned on the basis of the passage of time rather than accomplishment of specific events.

LEVEL OF EFFORT Effort that cannot be associated with a definable end product or result. Loe is planned and earned on the basis of the passage of time rather than accomplishment of specific events.

"LEVELS" PERTAINING TO DATA

See "raw data"

"LEVELS" PERTAINING TO ENGINEERING DRAWINGS

LEVEL 2 (PRODUCTION PROTOTYPE AND LIMITED PRODUCTION)

LEVEL 3 (PRODUCTION) Engineering drawings and associated lists that disclose a design approach suitable to support the manufacture of a production prototype and limited production models.

Engineering drawings and associated lists that provide engineering definition sufficiently complete to enable a competent manufacturer to produce and maintain quality control of item(s) to the degree that physical and performance characteristics interchangeable with those of the original design are obtainable without resorting to additional product design effort, additional design data or recourse to the original design activity.

LIMB SOUNDER A device or instrument that gives a signal by emitting sound, and measuring the response at the edge of the disk of the earth

LIST OF DATA FILES Within a data insert request, specifies the files which contain information (data and meta data) which is to be inserted.

LOGICAL GRANULE The smallest aggregation of data which is independently identified (i.e., described, inventoried). Source: ESADS.

LOGICAL RECORD A collection of data whose location and extent are defined in terms of the information it contains and not in terms related to the physical medium on which it is stored. Portions of the same logical record may be located in different physical records, or several logical records may be located in one physical record. Source: ESADS.

LOGICAL VOLUME That portion of a volume which is viewed by a computer operating system as a complete collection of available files. For instance, with today's WORM optical disk drives, each side of a two-sided disk is a logical volume. Source: ESADS.

LOGISTIC SUPPORT The composite of all considerations necessary to assure the effective and economical support of a system throughout its projected life cycle.

LOGISTICS The science of management, engineering and technical activities concerned with requirements, design and supplying and maintaining resources to support objectives, plans and operations.

LOGISTICS SUPPORT ANALYSIS (LSA) The selective application of systematic and comprehensive analyses, performed during the conceptual, design, development and operational phases as part of the system engineering and design process, to assist in complying with supportability and other ils objectives.

LOGON AUTHORIZATION REQUEST A message sent to csms to verify that a user is authorized to logon as an ecs user.

LONG TERM SPACECRAFT OPERATIONS PLAN Outlines anticipated spacecraft subsystem operations and maintenance, along with forecasted orbit maneuvers from the flight dynamics facility, spanning a period of several months.

LONG-TERM INSTRUMENT PLAN (LTIP) The plan generated by the instrument representative to the spacecraft's iwg with instrument-specific information to complement the ltsp. It is generated or updated approximately every six months and covers a period of up to approximately 5 years.

LONG-TERM SCIENCE PLAN (LTSP) The plan generated by the spacecraft's iwg containing guidelines, policy, and priorities for its spacecraft and instruments. The ltsp is generated or updated approximately every six months and covers a period of up to approximately five years.

MAGNETOMETER An instrument for measuring magnetic forces, esp. The force of terrestrial magnetism at any point

MAINTAINABILITY The measure of the ability of an item to be retained in or restored to a specified condition when maintenance is performed by personnel having specified skill levels, using prescribed procedures and resources, at each prescribed level of maintenance and repair. (the probability that maintenance, both corrective and preventive, can be performed in a specified amount of time using a specified set of prescribed procedures and resources expressed as mttr). Maintainability is the function of design.

MAINTENANCE The process of planning and executing life cycle maintenance concepts and requirements necessary to ensure sustained operation of system elements.

MAINTENANCE DOWNTIME The total elapsed time required to repair and restore a system to a full operational status and/or retain a system in that condition.

MAKE FILE (1) Input file for the unix make facility, which allows a user to specify dependencies between source (and other) files, primarily for compiling and linking programs, but also used for other activities, such as building documentation and installing software.

MAKEFILE (2) An encoded file listing all software components to be compiled and linked together; used for the c language compilers

MANTLE Layer of the Earth's interior between the core and crust, ranging from depths of approximately 2900 km-40 km. Source: EPO.

MASTER PROJECT SCHEDULE See master summary schedule

MASTER SUMMARY SCHEDULE The top level schedule that shows major project activities and events and key contractual milestones and deliveries. It is developed to display key management milestones. This schedule is used as the basis for all subsidiary schedules.

MEAN DOWN TIME (MDT) Sum of the mean time to repair mttr plus the average logistic delay times.

MEAN TIME BETWEEN FAILURE (MTBF) The reliability result of the reciprocal of a failure rate that predicts the average number of hours that an item, assembly or piece part will operate within specific design parameters. (mtbf=1/(l) failure rate; (l) failure rate = # of failures/operating time.

MEAN TIME BETWEEN MAINTENANCE (MTBM) The mean time between preventive maintenance (mtbpm) and mean time between corrective maintenance (mtbcm) of the ecs equipment. Each will contribute to the calculation of the mtbm and follow the relationship: 1/mtbm = 1/mtbpm + 1/mtbcm

MEAN TIME TO REPAIR (MTTR) The mean time required to perform corrective maintenance to restore a system/equipment to operate within design parameters.

MEASUREMENT MODE DUTY CYCLE The fraction of available time during which an instrument is actively performing Earth measurements and producing meaningful data, including incidental calibration and overhead (such as scan retrace). High data rate, high power consumption, and steerable instruments may have small duty cycles. Daylight-only instruments may have measurement mode duty cycles averaging 50 percent. Source: EPO.

MEDIA DESTINATION Media destination is information that describes where media is to be physically shipped.

MEDIA DISTRIBUTION REQUEST (1) A media distribution request contains distribution instructions consisting of the following:

A. Data format

B. Media specification

C. Media destination

D. Shipping information

MEDIA DISTRIBUTION REQUEST (2) A media distribution request is a distribution request that directs sdps to record data on hard media and ship it to a specified destination. See data request, for the format of a media distribution request.

MEDIA IDENTIFIER A media identifier is information used to uniquely identify a media cartridge.

MEDIA SPECIFICATION A media specification is information that describes the type and number of media cartridges required to record data for distribution.

MEDIA TYPE Type of hard media (e.G., 8mm tape) provided for ingest by an external data provider; type of hard media provided to a science user requesting hard media distribution.

MEMORY LEAK An erroneous use of memory by a program, such as reading from an uninitialized address, or writing to an address that has not been allocated.

MEMORY USAGE The amount of memory that a process requires to run.

MESOSPHERE Region of the atmosphere between approximately 50 and 85 km. Source: EPO.

MESSAGE The structured component in the mechanism for communicating information between an IMS client and archive databases. Different types of messages, corresponding to the functional subsystem of the IMS, are exchanged through the client/server architecture. Message types include, for example, inventory search and inventory result. Source: ESDIS IMS Lexicon.

METADATA (1) "data about data", used to facilitate database searches. Types of metadata include: product metadata (data describing a particular product, such as when it was generated, etc.) And algorithm metadata (data describing science software).

METADATA (2) Metadata is descriptive information that will accompany ecs data. Metadata identifies data; it describes the characteristics of data including its origin, content, quality, and condition; and it provides information needed to process and interpret data.

MILESTONE A specific, definable achievement or an event.

MILESTONE TABLE Table containing all contractual milestones, control milestones and interface milestones.

MODELLING An investigative technique that uses a mathematical or physical representation of a system or theory that accounts for all or some of its known properties. Models are often used to test the effects of changes of system components on the overall performance of the system.

MODULE A coherent subset of a system containing a tightly bound group of classes and their relationships.

MONTHLY COMPOSITE A product which combines geophysical parameter measurements taken over the course of a month into one visualizable summary

MULTIPLICITY The number of instances of one class that may relate to a single instance of an associated class

NADIR Direction toward the center of the Earth. Opposite of zenith. Source: EPO.

NEAR REAL-TIME DATA Data from the source that are available for use within a time that is short in comparison to important time scales in the phenomena being studied. Source: ESADS.

NEAR-LINE Near-line refers to tapes or other archive media that are typically stored for very quick access and loading on the computer system for use (i.e. robotic tape silos or optical disc jukeboxes). Source: EDC/ESDIS.

NEGATIVE FEEDBACK An interaction that reduces or dampens the response of the system in which it is incorporated.

NETWORK A flow diagram depicting the time phased sequence and interrelationship of events and activities that must be accomplished to achieve project objectives.

NETWORK INGEST REQUEST A network ingest request is an ingest request that directs sdps to automatically transfer data into the sdps from an external data provider. The network ingest request contains the following information:

A. External data provider;

B. Date/time prior to which the data will remain available;

C. Requested ingest priority;

D. List of data type identifiers;

E. For each data type identifier, a list of file identifiers; and

F. The corresponding file volumes.

NETWORK MANAGER A body of software modules that receive, interpret, and transmit, (depending on a particular state), an appropriate message to the archive server and the user interface software subsystems.

NONCONFORMANCE The failure of a unit or product to conform to specified requirements.

NOTIFICATION A notification is a message sent to a user that indicates that a user-specified event has occurred. The message may be an internal ecs message or an email message.

NUTRIENT Any substance assimilated by living things that promotes growth. Source: EPO.

OBJECT (1) A concept, abstraction, or thing with crisp boundaries and meanings for the problem at hand; an instance of a class

OBJECT (2) Identifiable encapsulated entities providing one or more services that clients can request. Objects are created and destroyed as a result of object requests. Objects are identified by client via unique reference.

OBJECT IMPLEMENTATION Code and data that realizes target object's behavior.

OBJECT REQUEST
BROKER (ORB) The orb locates object implementation, ensures implementation is ready, and transmits data and returns results.

OCEAN MIXING Processes that involve rates of advection, upwelling/ downwelling, and eddy diffusion and that determine, for example, how rapidly excess atmospheric carbon dioxide can be taken up by the oceans. Source: EPO.

OCEAN/CRYOSPHERE Ice coverage over the oceans

OFF-LINE Access to information by mail, telephone, facsimile, or other non- direct interface.

OFFICE MANAGER The person responsible for managing the cost, schedule, and technical elements of a major office's responsibilities on a project.

ON TIME QA On time qa is a response to a data quality request that is received within the established production time window. It is received from a scientist at a science computing facility. It consists of data which will be used to complete the qa fields of the metadata. Overdue qa responses are sent directly to the dads.

ON-DEMAND DATA PRODUCT An on-demand data product is a data product that is not stored, but is generated when requested by a user.

ON-LINE Access to information by direct interface to an information data base via electronic networking.

ON-SITE SDL

See software development library

ONBOARD ATTITUDE DATA Onboard attitude data is attitude data generated by the spacecraft or its instruments.

ONBOARD ORBIT DATA Onboard orbit data is orbit data generated by the spacecraft.

OPEN REQUEST An open request is a service request that directs a dim, lim, or data server to initiate a session and allocate resources required for the processing of service requests.

OPERATIONAL DATA Data created by an operational instrument (i.E., Noaa amrir).

OPERATIONAL FACILITY INSTRUMENT An instrument developed and operated by a national or international agency (e.g., NOAA, DOD) to support their operational requirements. Data from such an instrument may be made available to the research community. Source: ESADS.

OPERATIONS Within EOSDIS, those activities directly related to the acquisition, archiving, distribution, and processing of mission-related information. Source: EPO.

ORBIT DATA Data that represent spacecraft locations. Orbit (or ephemeris) data include: geodetic latitude, longitude and height above an adopted reference ellipsoid (or distance from the center of mass of the earth); a corresponding statement about the accuracy of the position and the corresponding time of the position (including the time system); some accuracy requirements may be hundreds of meters while other may be a few centimeters.

ORGANIZATIONAL BREAKDOWN A functionally oriented pyramid-like structure indicating structure organizational relationships and used as the framework for the assignment of responsibility.

OTHER USERS Those persons requesting data for scientific, operational, applications, or commercial use, who are not directly represented by an EO-ICWG member, and who agree to the stipulations on data access and use as set by the EOICWG and the EOS Program.

OZONE A molecule made up of three atoms of oxygen. In the stratosphere, it occurs naturally and provides a protective layer shielding the Earth from ultraviolet radiation and subsequent harmful health effects on humans and the environment. In the troposphere, it is a chemical oxidant and major component of photochemical smog. Ozone is an effective greenhouse gas especially in the middle and upper troposphere and lower stratosphere. Source: EPO.

P = V METADATA Label = value' where label is a field name and value is either a single value or list of values

PACKAGE A set of data granules organized for distribution by a DAAC. Source: ESDIS IMS Lexicon.

PACKAGING, HANDLING, STORAGE AND TRANSPORTATION (PHS&T) The resources, processes, procedures, design considerations and methods to ensure that all system, equipment and support items are preserved, packaged, handled and transported properly including environmental considerations and equipment preservation requirements for short and long term storage and transportability.

PARAMETER The output generated by applying predetermined transformation algorithms to previously existing products and ancillary data, using specified calibration coefficients, to represent a specific geophysical parameter. Included are level 2-4 products.

PARAMETRIC ANALYSIS A parametric analysis is used to obtain a close approximation of a units inherent reliability when creditable data is not available.. Parametric analysis compares a unit with known values and is similar to and used in a similar application as the unit in question. Parametric analysis uses the known units' r&m data as representative of the vendor's unit. This will often provide the best available estimate of the inherent reliability of a proposed cots item.

PATHFINDER A long-term, global earth science data set produced from non-eos data using community consensus algorithms as part of the eosdis program. Selection of pathfinder data sets is made by the eos program office (in consultation with the iwg and the science community).

PAYLOAD Complement of instruments for a mission on a spacecraft or spacecraft.

PERFORMANCE MANAGEMENT DATA Information collected by sdps and provided to mss about the performance of individual system components, such as current resource utilization or throughput.

PERFORMANCE MEASUREMENT Time phased budget plan against which contract baseline performance is measured. It is comprised of time phased cost account budgets, undistributed budgets, and indirect budgets. Management reserve is not a part of the performance measurement baseline.

PERFORMANCE MEASUREMENT Time phased budget plan against which contract baseline performance is measured. It is comprised of time phased cost account budgets, undistributed budgets, and indirect budgets. Management reserve is not a part of the performance measurement baseline.

PGE Product generation executive. The smallest scheduled unit of science software. A pge may consist of a single binary executable or a large number of executables wrapped by a shell script. To the ecs system, a pge is a completely black box.

PGE DATABASE "the database of information about the science software, organized by pge, used by the planning and data processing subsystems to execute the pges. Includes disk space and memory requirements, estimated run time, etc."

PGE INSTALLATION PACKAGE A single record in the pge database, containing all of the required information about a pge.

PHENOMENOLOGICAL SEARCH CRITERIA Phenomenological search criteria are search criteria that identify data associated with an event or condition that is observable by ecs instruments.

PHOTOSYNTHESIS The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll with sunlight as the energy source. Oxygen and water vapor are released in the process. Photosynthesis is dependent on favorable temperature and moisture conditions as well as on the atmospheric carbon dioxide concentration. Increased levels of carbon dioxide can increase net photosynthesis in many plants. Source: EPO.

PHYSICAL CONFIGURATION AUDIT The formal examination of the "as-built" configuration of a configuration item against its technical documentation to establish the ci's initial product configuration identification.

PHYSICAL GRANULE The smallest aggregation of data which is independently accessible (i.e., located, readable, reproducible) on physical media. Source: ESADS.

PHYSICAL MEDIUM Any physical material capable of holding data (e.g., pages, film, magnetic tape, optical disk, wire, silicon). Source: ESADS.

PHYSICAL RECORD A collection of data whose location and extent are defined in terms related to the physical medium on which it is stored. A physical record may contain one or several logical records or a part of a logical record. Source: ESADS.

PHYTOPLANKTON That portion of the plankton community in a body of water made up of tiny plants (e.g., algae and diatoms). Source: EPO.

PLAN ACTIVATION REQUEST A request to the planning csci to make a previously prepared plan (a candidate plan) active (i.E., The active plan).

PLAN CANCELLATION REQUEST A request to cancel an active plan.

PLAN CREATION REQUEST A request for creating a candidate plan based on the planning information provided as input.

PLANETARY ALBEDO The fraction of incident solar radiation that is reflected by a planet and returned to space. The planetary albedo of the Earth-atmosphere system is approximately 30 percent, most of which is due to backscatter from clouds in the atmosphere. Source: EPO.

PLANNING PACKAGE A future segment of work within a cost account that is not yet broken down into work packages. A planning package has a firm budget, estimated start and complete dates, and description of work.

PLATFORM The eos spacecraft and its subsystems without the instruments.

PLATFORM ENGINEERING DATA The subset of engineering data from platform sensor measurements and on-board computations.

PLAYBACK DATA Data that have been stored on-board the spacecraft for delayed transmission to the ground.

POINT SPATIAL OBJECTS A zero-dimensional object that specifies geometric location. One coordinate pair or triplet specifies the location. Area point, entity point, and label point are special implementations of the general case.

POLARIMETER A form of polariscope for measuring the amount of rotation of the plane of polarization, or the amount of polarized light in a beam.

POLLING INGEST REQUEST A polling ingest request is an ingest request that directs sdps to automatically transfer data into the sdps from an external data provider. The polling ingest request is triggered by periodic polling for files in a specified network-accessible location. The polling ingest request contains the specified network-accessible location.

POSITIVE FEEDBACK An interaction that increases or amplifies the response of the system in which it is incorporated.

PRELIMINARY DESIGN REVIEW (PDR) Pdr is held for each ecs segment. The pdr addresses the design of the segment-level capabilities and element interfaces through all ecs releases. The pdr also addresses prototyping results and how the results of both contractor and government prototyping efforts, studies, and user experience with eosdis version 0 have been incorporated into the ecs design for each respective segment.

PRELIMINARY RESOURCE SCHEDULE An initial integrated spacecraft schedule, derived from

Instrument and subsystem resource needs, that includes the network control center tdrss contact times and nominally spans seven days.

PREPLANNED COMMAND GROUP See "command group"

PREPLANNED STORED COMMAND A command issued to an instrument or subsystem to be executed at some later time. These commands will be collected and forwarded during an available uplink prior to execution.

PREVENTIVE MAINTENANCE All actions that are performed on a scheduled basis in an attempt to retain the operation of a system/equipment within specified operating parameters. Preventive maintenance includes but is not limited to: inspection, cleaning, filter changes, lubrication, calibration and alignment.

PRINCIPAL INVESTIGATOR (PI) An individual who is contracted to conduct a specific scientific investigation. (an instrument pi is the person designated by the eos program as ultimately responsible for the delivery and performance of standard products derived from an eos instrument investigation.).

PRINCIPAL INVESTIGATOR COMPUTING FACILITY (PICF)

Project-provided facilities at pi locations used to develop and maintain algorithms, produce data sets, and validate data.

PRINCIPAL INVESTIGATOR INSTRUMENT An instrument selected pursuant to the eos announcement of opportunity and provided by a pi and his home institution.

PRIORITY INFORMATION Priority information specifies the priority of a service request as assigned by a user or operations, or as assigned as the default or maximum priority a user can assign to a service request.

PROBLEM TRACKING TOOL Software tool for doing automated tracking of problems found in the science software, as well as the status of the resolution of those problems.

PROCEDURE A subroutine, function, or other module within a process.

PROCESS (1) A logical sequence of tasks by which a job is accomplished.

PROCESS (2) An executing program.

PROCESSING LEVEL IMS interface term. See Data Product Level.

PROCESSING PLATFORM A computer used to run science software. (as opposed to miscellaneous workstations and pcs used by the ai&t personnel for other purposes.)

PRODUCT A permanently archived set of output data generated by the science software.

PRODUCT BASELINE The baseline which establishes the "as-built" configuration for system-level integration and testing and independent acceptance testing. This baseline is validated by functional and physical configuration audits, and reviewed and approved by gsfc as part of rrr.

PRODUCT COORDINATION Product coordination is the coordination of the receipt, staging, and storage of data necessary to carry out the pgs processing schedule.

PRODUCT GENERATION EXECUTABLE (this is an obsolete term - see product generation executive.)

PRODUCT GENERATION EXECUTIVE A product generation executive (pge) is a set of one or more compiled binary executables and/or command language scripts; it is the smallest unit of processing managed by the planning and data processing subsystems.

PRODUCT GENERATION SYSTEM (PGS) An EOS DAAC element that performs data processing functions, including routine generation of Standard Data Products, routine generation of associated quick-look products, metadata, and browse data sets, reprocessing of data, and retrospective generation of new Standard Data Products. In practice, a PGS should consist of the hardware and application software at a DAAC used for generating data products. The PGS at a DAAC may also provide computational support for research and special product trials. Source: EPO.

PRODUCT ORDER Product order is either a request for the generation of a specific product with an associated time window, a priority processing request, a reprocessing request, or a standing order for a product to be generated on a regular basis with a rough timeline, or changes to standing orders. Product orders are received by the pgs from the ims.

PRODUCT REQUEST Within the IMS interface a request is an action initiated by a user to order data from a DAAC.

PRODUCT SPECIFIC METADATA Product specific metadata is metadata that describes characteristics of the instrument or applies only to a certain discipline, or is important only to a special segment of the science community.

PRODUCT STATUS DIALOG Product status dialog consists of information to assist the ims in tracking the status of a product order. The ims may send to the pgs a request for the status of a product to which the pgs would respond with the current product status. The pgs will send a schedule conflict notice to the ims if a product request will cause a schedule conflict and the ims may respond with an adjustment to the time window. Schedule conflicts not resolved at this level are resolved by the system management center. The pgs will send an overdue alert to the ims if it is clear that a product order will not be met on time.

PRODUCTION HISTORY A record of each step in the creation of a particular product identifying generating pge, inputs, and other variables.

PRODUCTION PLAN See active plan and candidate plan.

PRODUCTION REQUEST A production request is a service request that requests the processing of specified ecs data by a pre-existing ecs process. A production request contains the following information:

A. User identifier

B. Algorithm input requirements

C. Text description of need for processing

D. Level 0-4 data set/subset

E. Required time of generation

F. Requested priority for product processing

G. Resulting product type

H. Processing parameters

PROFILING The measurement of the science software's resource usage requirements, such as memory and disk space requirements, cpu time, etc.

PROGRAM MANAGEMENT REVIEW (PMR) Formal start of ecs design activities. The pmr is held to ensure a common understanding of how the ecs development effort will be managed.

PROJECT INTERMEDIATE SCHEDULE A summarization of selected activities in the detail schedules. This schedule will be the primary schedule used by the office managers to manage the scope of work assigned to them.

PROJECT NETWORK Network of project activities. The project network assures horizontal traceability at the project level.

PROJECT STATUS REVIEW (PSR) An extension to the pmr, this review provides the mechanism to manage the program resources associated with all other ecs reviews. This review is the forum for timely risk management and possible adjustments to the schedule.

PROTOTYPE Prototypes are focused developments of some aspect of the system which may advance evolutionary change. Prototypes may be developed without anticipation of the resulting software being directly included in a formal release. Prototypes are developed on a faster time scale than the incremental and formal development track.

PROTOTYPE PRODUCT Data product generated as part of a research investigation, of wide research utility, requiring too much data or computer power for generation at the investigator science computing facility, and accepted as a candidate standard product by the iwg. Prototype products will be generated at daacs, but their routine generation is not guaranteed and will not interfere with other standard product generation.

PROTOTYPING The construction of a solution of a design or implementation problem, the feasibility of which needs to be determined as early as possible in order to arrive at a critical decision.

PROTOTYPING RESULTS REVIEW (PRR) Prrs are held to publicize results of specific prototyping activities. The prrs are timed to mesh with the points in the development cycle where information regarding the prototype (or prototypes) will be needed. A prr is used to reach conclusions concerning incorporation of the prototype into the mainline system development.

QA STATISTICS Quality indicators associated with an individual data product including drop-outs, data gaps, out-of-range values, etc.

QUALITY ASSURANCE A subset of the total performance assurance activities generally focused on conformance to standards and plans.

QUERY A query is a search request conforming to the format and protocols required by a cots product that executes the search request.

QUICK-LOOK DATA Data received during one tdrss contact period which have been processed to level 0 (to the extent possible for data from a single contact). These are data that have been identified to edos as requiring priority processing

QUICK-LOOK PRODUCT Product produced at a pgs by applying science algorithms to quick-look data.

RADIOMETER An instrument with the design of illustrating the transformation of radiant energy into mechanical force

RADIOMETRIC ACCURACY The estimated bound of error expected for a set of radiation measurements, before or after radiometric correction of gain and offset variations has been applied.

RASTER SPATIAL OBJECTS One or more images and/or grids, each grid or image representing a layer, such that corresponding grid cells and/or pixels between layers are congruent and registered.

RAW DATA Data in their original packets, as received from the spacecraft and instruments, unprocessed by edos.

* level 0 - raw instrument data at original resolution, time ordered, with duplicate packets removed.

* level 1a - level 0 data, which may have been reformatted or transformed reversibly, located to a coordinate system, and packaged with needed ancillary and engineering data.

* level 1b - radiometrically corrected and calibrated data in physical units at full instrument resolution as acquired.

* level 2 - retrieved environmental variables (e.G., Ocean wave height, soil moisture, ice concentration) at the same location and similar resolution as the level 1 source data.

* level 3 - data or retrieved environmental variables that have been spatially and/or temporally resampled (i.E., Derived from level 1 or level 2 data products). Such resampling may include averaging and compositing.

* level 4 - model output and/or variables derived from lower level data which are not directly measured by the instruments. For example, new variables based upon a time series of level 2 or level 3 data.

RAW INSTRUMENT DATA Actual remotely sensed electromagnetic measurements which have not yet been converted to counts, nor radiometrically corrected

REAL-TIME COMMAND GROUP See "command group"

REAL-TIME DATA Data that are acquired and transmitted immediately to the ground (as opposed to playback data). Delay is limited to the actual time required to transmit the data.

RECONFIGURATION A change in operational hardware, software, data bases or procedures brought about by a change in a system's objectives.

REDUCTION METHOD The series of steps taken to extract a sampling of data in order to construct browse products, or to generate a product which is smaller in overall number of bytes but which still provides the scientific information needed by the investigator. These are the formulae used to create products with the same spatial and temporal coverage, but with fewer measurements per spatial region or time period within the product (subsampling), or formulae used to extract a smaller area of spatial or temporal coverage which has the same number of measurements per region or time period (subsetting).

REFINED ATTITUDE DATA Refined attitude data is generated by the fdf in response to a request from ecs.

REFINED ORBIT DATA Refined orbit data is generated by the fdf in response to a request from ecs.

REGRESSION TESTING Re-test to insure the continued correct functioning usually after the replacement or addition of functionality.

RELEASE INITIATION REVIEW (RIR) An internal review conducted at the start of the development phase of a release to revisit the requirements and issues associated with that particular release.

RELEASE READINESS REVIEW (RRR) Conducted at the ecs system level for a gsfc project review team upon completion of release acceptance testing. The independent acceptance test organization leads the rrr to determine, with the government acceptance test team and the contracting officer's technical representative, if the release is ready to be delivered, installed, and incorporated into the operational system.

RELIABILITY Reliability is the function of design. It is the probability that system/equipment will operate within design parameters under stated conditions, for a specified interval expressed as mtbf.

REPAIRED ATTITUDE DATA Repaired attitude data is provided by the fdf to cover a time period when the onboard attitude data was not available or was invalid.

REPAIRED ORBIT DATA Repaired orbit data is orbit data that is provided by the fdf to cover a time period when orbital measurements were not available or were invalid.

REPORT Documentation of some automated (such as standards checking) or manual (such as evaluation of a science software delivery) activity.

REPORT FILE An electronic copy of a report.

REQUEST IDENTIFIER A request identifier is information that uniquely identifies a service request. Request identifiers are referenced by status requests and other service requests that are used to monitor or control the execution of service requests.

REQUEST PRIORITY Request priority is information that determines (1) the order in which the processing of a service request will be initiated relative to other service requests, and (2) the priority for services and resources required for the processing of the service request.

REQUEST PRIORITY Request priority is information that determines the order in which a service request will be processed relative to other service requests waiting to be processed.

REQUEST STATE The state of a service request once accepted by the sdps (e.G., Queued, active, complete). The request state is returned as part of the service request status.

REQUESTS Mechanism through which clients acquire other object services.

REQUIREMENT A statement to which the developed system must comply. Varieties of requirements: levels 2, 3, 4; performance, functional, design, interface.

RESEARCH FACILITY INSTRUMENT An instrument provided and managed by an institution for use by a group of approved investigators. Data from the instrument may be made available for the operational applications. Source: ESADS.

RESEARCH USE A study or an investigation in which the user affirms (1) the aim is to establish facts or principles; (2) the data will not be sold or reproduced or provided to anyone not covered by this or another valid affirmation; (3) the results of the research will be submitted for publication in the scientific literature; and (4) detailed results of the research will be provided to the sponsoring spacecraft operator as agreed between the researcher and the sponsoring spacecraft operator. In the context of EOSDIS, this means that NASA-affiliated users must make available to the research community their detailed results, including data, algorithms, and models at the time their research is accepted for publication; and that the data may be copied and shared among other researchers provided that either they are covered by a research agreement or the researcher who obtained the data from EOSDIS is willing to take responsibility for their compliance with the agreement.

RESERVE That amount of a resource held by the EOS Program and Project to satisfy unanticipated requirements or objectives. Source: EPO.

RESULT Information generated and communicated from the archive (DAAC) to the IMS client and displayed in the user interface as a result of a user-initiated search.

RESULT SET A result set is data that is the output of an ecs service performed as a result of the execution of a service request.

RESULTS INTEGRATION The mechanism in the IMS client that merges, manages, and presents to the interface result messages received from the archives (DAACs).

RESUME REQUEST A resume request is a service request that directs a lim, dim, or data server to resume a suspended session.

RETURN LINK DATA Spacecraft health and status data and instrument data. Source: EPO.

REUSABLE SOFTWARE Software developed in response to the requirements for one application that can be used, in whole or in part, to satisfy the requirements of another application.

RISK An event, action, or thing with a: 1) potential loss associated with it, 2) uncertainty or chance involved, 3) some choice involved.

RISK MANAGEMENT The process of identifying, measuring, and controlling risk factors associated with a program development and/or support activity.

RUNS RELIABLY The software runs to normal completion repeatedly over the normal range of data inputs and run-time conditions.

RUNS SAFELY The software executes without interfering with other software or daac operations.

SCATTEROMETER, RADAR Instrument used to measure the variation of scattering coefficient with incident angle for radar signals, or to study the effect of polarization and wavelength variations.

SCC-STORED COMMANDS AND TABLES Commands and tables which are stored in the memory of the central onboard computer on the spacecraft. The execution of these commands or the result of loading these operational tables occurs sometime following their storage. The term "core-stored" applies only to the location where the items are stored on the spacecraft and instruments; core-stored commands or tables could be associated with the spacecraft or any of the instruments.

SCENARIO A description of the operation of the system in user's terminology including a description of the output response for a given set of input stimuli. Scenarios are used to define operations concepts.

SCHEDULE VARIANCE The arithmetic difference between earned value and planned value; represents schedule status in terms of dollars.

SCHEDULES Schedules represent the current sequence of tasks to be executed along with approximate execution times as generated by the pgs scheduler. Copies of these schedules, which are updated frequently, are made available to the ims, the system management center, and the dads.

SCHEDULING DIRECTIVE A scheduling directive is a message sent by the smc specifying the scheduling of testing and simulation activities for the system, site, or a subsystem.

SCHEDULING MANAGEMENT DATA Information about the schedules for the start up, shutdown, restart, or reservation of sdps resources.

SCHEMA INFORMATION A formal description of the data which are offered by an ecs data management service (dim, lim, data servers) and are accessible via that service's query language and query interface. The schema information includes a definition of the structure of the data types supported by that data management service, the attributes and operations supported by that data type, and the valid values (or range of values) for each attribute, as applicable.

SCIENCE COMPUTING FACILITY A facility supplied by the eos program to an eos team leader, team member, or principal investigator (instrument or interdisciplinary) for the following purposes: developing and maintaining the algorithms and software used to generate standard data products; quality control of standard data products; in-flight instrument calibration and data set validation; scientific analysis, modeling, and research' generation of special data products; and use as an interface to the investigator's institutional facility.

SCIENCE PROCESSING LIBRARY (SPL) The spl is a repository of software, contributed by scientists and other users, to which ecs will provide access in order to facilitate the reuse of software throughout the community. This software is made available as it was contributed with ecs performing only a cataloging function to identify for users what is available. Ecs is not responsible for the validity or maintenance of the software contained in the science processing library.

SCIENCE SOFTWARE Software developed by the scfs to generate standard (and other) science data.

SCIENCE SOFTWARE ARCHIVE PACKAGE (1) All of the files associated with a particular set of science software. This includes all of the files delivered by the scf to the daac, as well as additional files generated during the integration and test process.

SCIENCE SOFTWARE ARCHIVE PACKAGE (2) Includes the science software delivery package and the information generated during integration and test.

SCIENCE SOFTWARE DELIVERY All of the files delivered by the scf to the daac which are associated with a particular set of science software. This includes: source code, include files, shell scripts, make files, documentation, test procedures, test inputs and outputs, etc.

SCIENCE SOFTWARE DELIVERY PACKAGE The source code, scripts, make files, documentation, test plans, test inputs and outputs, calibration coefficients, control files, etc. That are delivered for formal integration and test.

SCIENCE SOFTWARE DOCUMENTATION Documentation associated with a particular set of science software, in electronic form.

SCIENCE SOFTWARE SCRIPT Any shell script which is part of the science software and which must be run in order to produce output products (as opposed to scripts which are supplied to help in the integration and test process).

SCIENCE SOFTWARE SOURCE CODE Any source code which is part of the science software and which must be run in order to product output products (as opposed to code which is supplied to help in the integration and test process).

SCIENTIST

SEE ALSO "INVESTIGATOR" A scientist is an individual having interest in the direct usage or support of the data which is collected and generated by, or the instruments which are contained within the eosdis. Included are principal investigators, co-investigators, research facility team leaders and team members, interdisciplinary investigators, instrument investigators, non-eos affiliated science users, and other users of a diverse nature.

SCREEN CAPTURE A facility for taking a ""snapshot"" of what is being displayed on a workstation or pc, and saving the snapshot to a file which can then be displayed or printed via a paint program.

SDP TOOLKIT A set of sdps-standard api between science algorithms and the process execution service for status reporting and process control

SEARCH Within the IMS interface search is the action of composing a set of criteria for locating information. These criteria are communicated to the DAACs in a search message structure where it is processed, through DAAC mapping layers, into local database queries.

SEARCH CRITERIA Search criteria specify categories to which data belongs and are used to identify a required subset of available data.

SEARCH REQUEST A search request is a service request that requests information that describes data. The service request contains search criteria. The execution of the search request produces a list of one or more members that describe the data belonging to the categories given by the search criteria. The resulting members can be used to formulate subsequent search requests or data requests.

SEARCH RESULT The output of a search request.

SECURITY MANAGEMENT DATA Information collected by sdps and provided to mss for the purpose of managing the security of the sdps services and data. The information includes records of user logon and logoff, and of unauthorized attempts to access sdps services and data

SECURITY MANAGEMENT DATA Security management data is information (e.G., Logon and logoff information) that is sent to mss for reporting, tracking and alert purposes.

SEGMENT One of the three functional subdivisions of the ecs:

Csms -- communications and systems management segment

Fos -- flight operations segment

Sdps -- science data processing segment

SEGMENT OPERATIONAL READINESS REVIEW (SORR) (1) Conducted for each release to determine if the operation plans are in place prior to turnover to iv&v and operations.

SEGMENT OPERATIONAL READINESS REVIEW (SORR) (2) Sorrs shall be conducted to review the readiness of site operations to receive ecs software for a release. Sorr may be held coincident with csr. Responsibility for review is site management. The review shall focus on functional capabilities, performance and operational characteristics of each segment. The sorr shall concentrate on operational procedures, human interfaces and operational readiness.

SENSOR A device which transmits an output signal in response to a physical input stimulus (such as radiance, sound, etc.). Science and engineering sensors are distinguished according to the stimuli to which they respond.

* sensor name: the name of the satellite sensor which was used to obtain that data.

SERVICE A grouping of functional requirements as listed in a specification. For example, in the level 3 requirements, ims "services" are system access, information search, etc.

SERVICE DESCRIPTION A description of the functions and interfaces provided by an sdps service, intended for inclusion in an advertisement.

SERVICE REQUEST A service request is a message that requests data, a service, or both. The message is generated by an ecs client and sent to an ecs server. The server executes the service request and generates service request status information and/or results. A service request contains the following data:

A. User identifier

B. Request identifier

C. Priority information

D. Request state

E. If rejection, then the reason for the rejection.

SERVICE REQUEST COST An aggregate measure of the resources required by a service request.

SERVICE REQUEST STATUS Information describing either the current progress of an ongoing service request or the outcome of a completed service request.

SERVICE REQUEST THRESHOLD A service request threshold specifies the number of service requests which may be queued.

SESSION LOG A record of the service requests issued by a user in the context of a session.

SESSION PROFILE A session profile is information associated with a user session that is used to supply default parameters in service requests. The contents of the session profile is derived from the user profile and from information supplied directly by the user during the user session.

SESSION STATUS INFORMATION Session status information includes information about the resources allocated to the session, resources consumed by the transaction, service request status of the service requests associated with that session, and session state (e.G., Active, dormant, suspended).

SIGNAL-TO-NOISE RATIO (S/N) The ratio of the level of the information-bearing signal power to the level of the noise power. For MODIS, the ratio between (1) typical cloud free scene brightness with solar zenith angle Z=70 deg, and (2) all sensor and processing noise contributions. S/N specifications for various scenes (e.g., land, clouds, oceans, ice) are only applicable in the filter bands associated with those scenes. Source: EPO.

SIMULATED DATA Simulated data - same as test data

SITE QUERY PLAN A site query plan is an organized set of search requests formulated by the local information manager for the purpose of executing a search request involving multiple data servers at a site. Each search request within the site query plan is intended to be processed by a single data server.

SITE SEARCH REQUEST A site search request is a search request that is intended to be processed at a single site by a lim.

SOFTWARE A combination of associated computer instructions and computer data definitions required to enable the computer hardware to perform computational, data manipulation, and control functions (to include parameters and procedures associated with software products).

SOFTWARE DEVELOPMENT FILE A repository for a collection of material pertinent to the development or support of software. Contents typically include (either direct or by reference) design considerations and constraints, design documentation and data, schedule and status information, test requirements, test cases, test procedures, and test results.

SOFTWARE DEVELOPMENT LIBRARY (SDL) A generic term which describes a controlled collection of software, documentation, and associated tools and procedures used to simplify the development and subsequent support of software. An SDL provides storage of and controlled access to software in both human readable and machine readable form. Also, it may contain management data pertinent to the software development project.

SOURCE Source of data, taken in the broadest sense, can include the originating organization as well as the observational environment and its subsystems without the instruments. Examples have been extended to include originating data center, a person, and a platform such as an aircraft, balloons, buoys, ground stations, as well as spacecraft. In many cases the source may be an aggregate field, for example the source for "in-situ" data may be a generic term ( e.g., buoys) rather than a specific term (e.g., buoy #12345). Source: ESDIS, NSIDC.

SPACE NETWORK (SN) The NASA assets required to communicate with Earth-orbiting spacecraft via the TDRSS. Source: EPO.

SPACE/TIME EXTENT The amount of area or the amount of time covered by a particular set of data, or by a region, event, or season.

SPACECRAFT The spacecraft is the EOS space or orbiting component composed of the payload and mission-unique equipment required to support the EOS mission. It includes propulsion, separation springs, and user interface equipment not unique to the launch vehicle. Source: EPO.

SPACECRAFT ENGINEERING DATA The subset of engineering data from spacecraft sensor measurements and on-board computations.

SPACECRAFT SUBSYSTEMS ACTIVITY LIST A spacecraft subsystem's list of activities that nominally covers

Seven days, used by the eoc for developing the detailed activity schedule.

SPACECRAFT SUBSYSTEMS RESOURCE PROFILE Anticipated resource needs for a spacecraft subsystem over a

Target week, used by the eoc for establishing tdrss contact times and building the preliminary resource schedule.

SPATIAL RESOLUTION The smallest area of the globe or of the atmosphere for which full granule content will be provided

SPECIAL DATA PRODUCT A special data product is either a data product which is considered part of a research investigation and is produced for a limited region or time period, or is a data product which is not accepted as a standard product.

SPECIFICATION A document intended primarily for describing the essential technical requirements for items, material or services, including the procedures for determining whether or not the requirements have been met.

SPECTROMETER An instrument used for measuring the index of refraction

STAGING INSTRUCTIONS Staging instructions is information that describes how data is to be staged and contains the required data format for the staged data.

STAGING REQUEST A staging request is a data request that directs sdps to place specified data in a user-accessible staging area. The data can be permanently stored or generated on-demand. See data request, for the format of a staging request.

STANDARD PRODUCT (1) a data product generated as part of a research investigation, of wide research utility, accepted by the iwg and the eos program office, routinely produced, and in general spatially and/or temporally extensive. Standard level 1 products will be generated for all eos instruments; standard level 2 products will be generated for most eos instruments. (2) a data product which has been accepted for production at a pgs, including (1) above, as well as a prototype product. This may include browse data products that are generated as part of the product production process.

STANDARDS CHECKING The process of checking whether or not source code and shell scripts follow prescribed coding standards.

STATEMENT OF WORK A description of the end objectives, scope, and constraints of a unique and separately identifiable portion of the work required to satisfy contract requirements.

STATIC BROWSE Refers to interrogation of browse products which have been generated (through subsetting and/or resampling) before any user browses that particular data set.

STATIC DATA SETS Static data sets are those containing parameters whose values may change, but not routinely at set intervals in time.

STATUS Status is information regarding schedules, hardware and software configuration, exception conditions, or processing performance. This information is exchanged with the DADS, and is provided to the system management center (SSMC). The SSMC may also receive information regarding schedule conflicts that have not been resolved with the IMS.

STATUS REQUEST A status request is a service request that requests the status of one or more active service requests. A status request contains the following data:

A. User identifier

B. Request identifier(s) for the statused service request(s)

STRATOSPHERE Region of the atmosphere between the troposphere and mesosphere, having a lower boundary of approximately 8 km at the poles to 18 km at the equator and an upper boundary of approximately 50 km. Depending upon latitude and season, the temperature in the lower stratosphere can increase, be isothermal, or even decrease with altitude, but the temperature in the upper stratosphere generally increases with height due to absorption of solar radiation by ozone. Source: EPO.

STRUCTURE Organizational relationships and used as the framework for the assignment of responsibility.

SUB SAMPLING Standard sub sampling involves extraction of a multi-dimensional rectangular array of pixels from a single data granule, where regularly-spaced, non-consecutive pixels are extracted from each array dimension. For each dimension, the size of the pixel array is characterized by the starting pixel location, the number of pixels to extract, and the pixel-spacing between extracted pixels.

SUBCLASS A refined version of another class, the superclass. An instance of the subclass is also an instance of the superclass.

SUBSAMPLE Extract a non-contiguous regular partition across some set of data, usually for the purposes of obtaining the general nature of the data measured rather than the fullest level of detail. Examples include taking every 10th pixel, or measurements taken once per minute or hour.

SUBSCRIPTION A request for an action to be taken whenever a particular event occurs. Usually, a request to be notified whenever certain specified data is produced or received under certain specified conditions.

SUBSCRIPTION A subscription is a specification for an action to be performed upon the occurrence of one or more user-specified events. The action to be performed may be (1) the execution of another service request or (2) the issuance of a notification. The service request to be executed may perform data processing or may deliver data. The specified event(s) may correspond to the availability of data or to the periodic expiration of a timer. Subscriptions are stored and activated by the data server subsystem. Once a subscription is activated, the subsystem will detect the events specified in the subscription as they occur.

SUBSCRIPTION EVENT A subscription event is an event that triggers a specified action. Both the event and the action are specified in a subscription.

SUBSCRIPTION IDENTIFIER A subscription identifier is information that uniquely identifies an active or expired subscription.

SUBSCRIPTION REQUEST A subscription request is a service request for the acceptance and activation of a subscription by the data server subsystem. A subscription request contains a subscription.

SUBSCRIPTION UPDATE REQUEST A request by a client to change information recorded in an existing subscription.

SUBSET Extract a contiguous partition of some set of data, usually for the purposes of limiting the scope of that data to an area of specific interest. Examples include asking for one full hour out of a product that spans an entire 24-hour period, or some specified region of the north atlantic ocean from a product that spans the global oceans, or asking for 3 or 4 cloud properties in a product that provides 40 geophysical parameters at the same time and regions.

SUBSETTING Standard subsetting involves extraction of a multi-dimensional rectangular array of pixels from a single data granule, where consecutive pixels are extracted from each array dimension. For each dimension, the size of the pixel array is characterized by the starting pixel location and the number of pixels to extract.

SUBSYSTEM A combination of sets, groups, etc., Which performs an operational function within a system and is a major division of a system.

SUMMARY STATISTICS The set of statistical representations of individual data products, summarizing values over a set of granule instances of the product, such as in/ax values, means, standard deviations.

SUPERCLASS A more abstract version of another class, the subclass.

SUPPLY SUPPORT All management actions, procedures and techniques required to determine requirements for, acquire, catalog, receive, store, transfer, issue and dispose of secondary items. This includes provisioning for initial support as well as replenishment supply support.

SUPPORT EQUIPMENT (1) Equipment used to interface with the spacecraft for the purpose of simulating the command and telemetry interface which will be present in the EOC, as well as providing additional status information that may be necessary in the integration and verification processes. Source: EPO.

SUPPORT EQUIPMENT (2) All equipment required to support the operation and maintenance of a material system. This includes associated multi-use end items, ground handling and maintenance equipment, tools, calibration equipment, communications resources, test equipment and automatic test equipment with diagnostics software for both on-and-off equipment maintenance. It also includes the acquisition of logistics support for the support and test equipment itself.

SUPPORTABILITY The ability of design characteristics and logistic resources to sustain system elements in a ready and usable status.

SUSPEND REQUEST A suspend request is a service request that directs a lim, dim, or data server to suspend an active session. Service requests may not reference data and services that were previously created or defined within the context of a suspended session.

SYSTEM HIERARCHY A set of terms used to decompose the system into smaller "building blocks." The ecs sow identifies system, segments, elements, and subsystems. This sdp further decomposes subsystems into hwcis, cscis, cscs, and csus.

SYSTEM A composite of equipment, skills, and techniques capable of performing or supporting an operational role (or both). A complete system includes all equipment, related facilities, material, software, services and personnel required for its operation and support to the degree that it can be considered a self-sufficient item in its intended operational environment.

SYSTEM DESIGN REVIEW (SDR) The SDR addresses the top-level ECS design. The SDR includes the definition and high-level design of ECS segments and elements, the interfaces between these and the interfaces between these and external systems, facilities, users, operators, etc.

SYSTEM FACILITIES All system real property assets required to develop and operate system elements.

SYSTEM REQUIREMENTS REVIEW (SRR) The SRR encompasses a complete review of the ECS specification and the EOS/EOSDIS Requirements (Level 2) that drive the specification, it promotes a common understanding between the Project and the Contractor of the capabilities that ECS must provide.

TARGET OF OPPORTUNITY (TOO) A too is a science event or phenomenon that cannot be fully predicted in advance, thus requiring timely system response or high-priority processing.

TEAM LEADER (TL) The person designated by the EOS Program as ultimately responsible for the delivery and performance of Standard Data Products derived from an EOS Facility Instrument. Source: EPO.

TEAM MEMBER (TM) A person designated by the EOS Program to develop algorithms for Standard Data Products derived from an EOS Facility Instrument. Source: EPO.

TEAM MEMBER COMPUTING FACILITY (TM CF) Project-provided facilities at research instrument team member locations used to develop and test algorithms and assess data quality.

TECHNICAL DATA All recorded, engineering and technical information defining form, fit, function and integrated logistics support for the system.

TELEMETRY A space-to-ground data stream of measured values (including instrument science data, instrument engineering data, and spacecraft engineering data) that does not include command, tracking, computer memory transfer, audio, or video signals. Source: EPO.

TEMPORARY FILE Temporary file is a file which may exists for the duration of a single PGE, or may exist for some indeterminate time beyond the termination of the PGE which created it.

TEST A procedure or action taken to determine under real or simulated conditions the capabilities, limitations, characteristics, effectiveness, reliability or suitability of a material, device, system, or method.

TEST DATA Test data is any data set designed or specially selected to aid in the algorithm integration and test process, to help test the operation of algorithms under development by simulating realistic input.

TEST PRODUCTS Test products are science products generated by new or updated algorithms during the integration and test period. Test products are delivered to scientists at a science computing facility.

TEST READINESS REVIEW (TRR) Conducted by the project for each release at the segment and element levels to review the plans for the integration and verification of the subsystems with the elements and the elements with their segments.

TESTING An element of inspection and generally denotes the determination by technical means of the properties or elements of supplies, or components thereof, including functional operation, and involves the application of scientific principles and procedures.

THERMOSPHERE Outermost layer of the atmosphere, above the mesosphere. Source: EPO.

THREAD

A set of components (software, hardware, and data) and operational procedures that implement a function or set of functions.

THREAD, AS USED IN SOME SYSTEMS ENGINEERING DOCUMENTS A set of components (software, hardware, and data) and operational procedures that implement a scenario, portion of a scenario, or multiple scenarios.

TOOLKITS Some user toolkits developed by the ecs contractor will be packaged and delivered on a schedule independent of ecs releases to facilitate science data processing software development and other development activities occurring in parallel with the ecs.

TRACE GAS A minor constituent of the atmosphere. The most important trace gases contributing to the greenhouse effect are water vapor, carbon di-oxide, ozone, methane, nitrous oxide, and chloro-fluorocarbons. Other trace gases include ammonia, nitric oxide, ethylene, sulfur dioxide, methyl chloride, carbon monoxide, and carbon tetrachloride. Source: EPO.

TRACK-BASED Refers to an instrument which does not scan across its orbital path in collecting data, but simply takes a reading directly along the path.

TRACKING AND DATA RELAY SATELLITE SYSTEM (TDRSS) A constellation of NASA satellites and ground stations that track and relay data to and from low-altitude, Earth-orbiting satellites (including the Space Shuttle). This NASA system includes specialized communications satellites located in geosynchronous orbit both east and west of the continental U.S. (providing coverage of virtually the whole globe) and a TDRSS Ground Terminal at White Sands, New Mexico. Beginning in 1995P96, redundant Ground Terminals are scheduled to be in place at White Sands. Source: EPO.

TRAINING The processes, procedures, devices and equipment required to train personnel to operate and support system elements.

TRANSPORTATION All necessary actions, resources and methods necessary to ensure the proper and safe movement of system elements and material. Included are the packaging, handling, and storage of items.

TROPOPAUSE Boundary between the upper troposphere and the lower stratosphere that varies in altitude between approximately 8 km at the poles to 18 km at the equator. Source: EPO.

TROPOSPHERE Lowest atmospheric layer, between the surface and tropopause. Source: EPO.

UNIT An assembly of any combination of parts, subassemblies and assemblies mounted together which are normally capable of independent operation in a variety of situations.

UNIVERSAL REFERENCE A uniform model for referencing objects throughout SDPS which each SDPS service will understand and support.

UNIVERSAL TIME A single time of day common to the entire globe, the origin of which is in utah rather than the u.K. (as for utc)

UPDATE METADATA REQUEST An update metadata request is a service request that directs the data server subsystem to modify specified metadata associated with ecs data products..

UPWELLING The vertical motion of water in the ocean by which subsurface water of lower temperature and greater density moves toward the surface of the ocean. Upwelling occurs most commonly along the western coastlines of continents, but may occur anywhere in the ocean. Upwelling results when winds blowing nearly parallel to a continental coastline transport the light surface water away from the coast. Subsurface water of greater density and lower temperature replaces the surface water, and exerts a considerable influence on the weather of coastal regions. Carbon dioxide is transferred to the atmosphere in regions of upwelling. This is especially important in the Pacific equatorial regions, where 1 to 2 gigatons of carbon per year may be released to the atmosphere. Upwelling also results in increased ocean productivity by transporting nutrient-rich waters to the surface layer of the ocean. Source: EPO.

USER A user is a person that originates service requests to be processed by sdps. Includes science users, and operations staff.

USER Any person accessing the EOSDIS. AUTHORIZED USERS are users who have viable EOSDIS accounts, and who may therefore make EOSDIS data requests. These users may be Affiliated or Unaffiliated. AFFILIATED USERS are those who are sponsored by one of the parties to the Earth Observations ICWG (EO-ICWG) data policy. Each party is responsible for ensuring that all its affiliated users comply with the EO-ICWG data policy. Use of data by Affiliated Users is classified in one of three categories, defined in the EO-ICWG data policy: (Source: EPO.) + Research Use: A study or an investigation in which the user affirms (1) the aim is to establish facts or principles; (2) the data will not be sold or reproduced or provided to anyone not covered by this or another valid affirmation; (3) the results of the research will be submitted for publication in the scientific literature; and (4) detailed results of the research will be provided to the sponsoring spacecraft operator as agreed between the researcher and the sponsoring spacecraft operator. In the context of EOSDIS , this means that NASA-affiliated users must make available to the research community their detailed results, including data, algorithms, and models at the time their research is accepted for publication, and that the data may be copied and shared among other researchers provided that either they are covered by a research agreement or the researcher who obtained the data from EOSDIS is willing to take responsibility for their compliance with the agreement. Data for affiliated users and for research and applications use will be made available at no more than the marginal cost of production and distribution. + Environmental Monitoring and Operational Use: Includes data use by those government agencies affiliated with the parties which conduct environmental monitoring and/or operational observations for the public good, and can include larger agencies to which the parties belong (i.e., the World Meteorological Organization); or national agencies, or their designates, involved in other operational forecasting activities which are conducted for the public good (i.e., weather, sea state, sea ice, agriculture, hydrology, etc.). Environmental Monitoring and Operational Use of Data constitutes any use of data to carry out a mandate of environmental observation and prediction as part of an agency's responsibilities to provide for the general welfare. Such use may include the routine downlink or direct broadcast of enhanced and unenhanced data in near-real time within the operational community. Data for Environmental Monitoring and Operational use shall be provided in real or near-real time without fee, and shall be available through international EOS archives for non-real time users for no more than the marginal cost of reproduction and distribution consistent with the access terms for each instrument category. + Other users: Those persons requesting data for scientific, operational, applications, or commercial use, who are not directly represented by an EO-ICWG member, and who agree to the stipulations on data access and use as set by the EO-ICWG and the EOS program.

USER ACCOUNTING INFORMATION Is accounting management data recording the resource utilization attributed to a specific used

USER COMMENTS User comments is user feedback information containing at a minimum:

A. Product data quality assessment

B. Schedule performance assessment

C. Evaluation of quality of ecs service.

USER IDENTIFIER A user identifier is information that uniquely identifies an authorized user of sdps services.

USER PROFILE A user profile is information associated with a user that is used to control the user interface and supply default parameters in service requests. The contents of the user profile is derived from system default parameters and information supplied directly by the user. The user profile will contain the following information at a minimum:

A. User electronic address

B. Media specification (for distribution media)

C. Data distribution address

D. User expertise level

E. Default search parameters

F. Terminal characteristics

G. Technical specialty

USER REGISTRATION REQUEST A message sent to csms to request the creation of a new user account.

USER SESSION LOG A user session log is a log that records the following information and activities associated with a single user session:

A. Service requests initiated by the user

B. Service request status

C. Notifications

USER VALIDATION STATUS A message sent by csms, in response to a logon authorization request, which indicates whether or not a user is authorized to logon as an ecs user.

V0 ADVERTISING INFORMATION V0 advertising information is a message, in version 0 format, that describes data and services that are provided by version 0.

V0 BROWSE REQUEST A v0 browse request is a message, in version 0 format, that directs the recipient of the request to provide browse data.

V0 BROWSE RESULTS V0 browse results are the output of a v0 browse request.

V0 INVENTORY SEARCH REQUEST A v0 inventory search request is a message, in version 0 format, that directs the recipient of the request to provide information that describes data that can be provided by the recipient.

V0 INVENTORY SEARCH RESULTS V0 inventory search results are the output of a v0 inventory search request.

V0 MIGRATION DATA Many of the v0 data holdings will be migrated into ecs data server data holdings. The data being ingested by ecs for that purpose is called the v0 migration data.

V0 PRODUCT REQUEST A v0 product request is a message, in version 0 format, that directs the recipient of the request to provide a data product.

VALID A value of a particular attribute (or column in a database). Valids (or keywords in the IMS interface) are both the search criteria and the key descriptions of attributes for inventory information. For example, "radiance" is a keyword within the attribute domain Parameter.

VALID VALUES Valid values are parameter values that describe the acceptable values for a given parameter.

VALIDATION The process of evaluating a system or component during or at the end of the development process to determine whether it satisfies specified requirements.

VARIANCE ANALYSIS Identification and explanation of deviations from a planned baseline.

Vdata A framework for storing customized tables in hierarchical data format files. Vdata is accessed via a Vdata interface and can be organized into Vdata classes.

VECTOR SPATIAL OBJECTS Objects composed of directed lines. See spatial reference information object class for further domain definitions.

VERIFICATION The process of evaluating the products of a given development activity to determine correctness and consistency with respect to the products and standards provided as input to that activity.

VERSIONS Versions are the culmination of a series of ecs releases, in conjunction with incorporation of scf-developed science data processing software and unique site capabilities.

Vgroup An aggregate of Vdata classes.

VISUAL AIDS Any graphical representation of data used to communicate the contents or meaning (including spatial and temporal location) of the data.

VOLUME A unit of physical media which contains data, usually physically interchangeable with other volumes of a similar type, and requiring a specific device for reading or writing (e.g., a CD-ROM). Source: ESADS.

WAIVER A written authorization to accept a configuration item that departs from specific requirements but considered suitable for use "as is" or after rework by an approved method.

WAIVER, CONFIGURATION MANAGEMENT SPECIFIC A written authorization to accept a configuration item that departs from specific requirements but considered suitable for use "as is" or after rework by an approved method.

WAIVER, ENGINEERING A written authorization to accept an item, which during manufacture or after having been submitted for inspection, is found to depart from specified requirements, but nevertheless is considered suitable for use as is or after repair by an approved method.

WORK AUTHORIZATION AND DELEGATION The document that assigns responsibility and authority for a defined task within a specified schedule, budget, and statement of work.

WORK BREAKDOWN STRUCTURE A product/service oriented logical subdivision of hardware, software, services, and other related tasks that shows how work is planned, performed, and managed.

WORK PACKAGES A natural subdivision of activities within a cost account.

WORKING STORAGE ALLOCATION REQUEST A request for the allocation of temporary storage.

WWW BROWSER Software (local or remote) which allows a user to access the www either textually or graphically. Www (world wide web) is a mechanism for connecting internet via a set of hypertext documents.

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