SIR-C Mode Table

SIR-C Radar Modes

The SIR-C radar has various modes of operation which are different combinations of frequency and polarization (see Table below). Modes 1 through 16 were the primary modes of operation; most of the repeat-pass interferometry data collected during the last three days of SRL-2 were collected in Mode 20. Different modes were used for each datatake depending on the primary science goal of the datatake. For example, geology datatakes were often taken in Mode 11 which provides dual frequency and dual polarization data and a swath width of approximately 30-50 km thereby providing good data coverage. Ecology datatakes were often taken in mode 16 which is dual frequency and quad polarization; due to the greater amount of data collected in mode 16, the swath width is narrower and is typically 10-25 km wide. Many sites were imaged in more than one mode on different data passes. The mode information for each datatake is included in a text file posted with the survey data at the EROS Data Center for each datatake. This text file, called DTHDR.TXT has the mode information on line #6.

The columns headed by "channel 1", "channel 2", etc., indicate the data recorded to each of four high density digital recorders on-board the Space Shuttle during mission operations. Therefore, to find out which frequencies and polarizations were recorded for a particular mode, just look up all the frequencies and modes saved to the four recorder channels. In order to double the swath, the same frequency and polarization was saved to more than one channel.

The frequency and polarizations letter abbreviations indicate the following :

• LHH - L-band, Horizontal transmit and receive
• LVH - L-band, Vertical transmit, Horizontal receive
• LHV - L-band, Horizontal transmit, Vertical receive
• LVV - L-band, Vertical transmit and receive
• CHH - C-band, Horizontal transmit and receive
• CVH - C-band, Vertical transmit, Horizontal receive
• CHV - C-band, Horizontal transmit, Vertical receive
• CVV - C-band, Vertical transmit and receive

Mode	Channel 1	Channel 2	Channel 3	Channel 4	Notes
0	---	---	---	---	X-SAR only
1	LHH	LHH	LHV	LHV	Double swath
2	LVH	LVH	LVV	LVV	Double swath
3	CHH	CHH	CHV	CHV	Double swath, APL receives CH
4	CVH	CVH	CVV	CVV	Double swath
5	LHH	LHH	LVV	LVV	Double swath
6	CHH	CHH	CVV	CVV	Double swath
7	LHH	LHH	CVV	CVV	Double swath, APL receives CH
8	LHH	LHH	CHH	CHH	Double swath
9	LVV	LVV	CVV	CVV	Double swath
10	LVH	LVH	CVH	CVH	Double swath, APL receives CV
11	LHH	LHV	CHH	CHV	Normal swath
12	LVH	LVV	CVH	CVV	Normal swath
13	LHH	LVV	CHH	CVV	Normal swath
14	LHH	LVH	LHV	LVV	Normal swath
15	CHH	CVH	CHV	CVV	Normal swath
16	LHH,LVH	LHV,LVV	CHH,CVH	CHV,CVV	Reduced swath
17	LHH	LHH	LVV	LVV	Normal swath, 40 MHz experimental mode
18	CHH	CHH	CVV	CVV	Normal swath, 40 MHz experimental mode
19	LHH	LHH	CHH	CHH	Normal swath, 40 MHz experimental mode
20	LVV	LVV	CVV	CVV	Normal swath, 40 MHz experimental mode
21	LVH	LVV	CVV	CVV	Normal swath, interferometry mode
22	CVV	CVV	CVV	CVV	Double swath, interferometry mode
23	LVH,LHH	LVV,LHV	CVH,CHH	CVV,CHV	Normal swath

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