Common NMEA Setence types
The following information describes the most common NMEA-0183 sentences transmitted by GPS receivers.
The NMEA standard provides quite a range of sentences, but many relate to non-GPS devices and
some others are GPS related but rarely used. We normally recommend the use of NMEA mode for new GPS
applications to give maximum compatibility with all GPS receivers. Most GPS receivers also have
a binary mode but it is normally best to reserve the use of binary GPS protocols for applications that really require
their use, such as those requiring position updates of greater than once per second.
| Sentence | Description |
| $GPGGA | Global positioning system fixed data |
| $GPGLL | Geographic position - latitude / longitude |
| $GPGSA | GNSS DOP and active satellites |
| $GPGSV | GNSS satellites in view |
| $GPRMC | Recommended minimum specific GNSS data |
| $GPVTG | Course over ground and ground speed |
$GPGGA Sentence (Fix data)
Example (signal not acquired): $GPGGA,235947.000,0000.0000,N,00000.0000,E,0,00,0.0,0.0,M,,,,0000*00
Example (signal acquired): $GPGGA,092204.999,4250.5589,S,14718.5084,E,1,04,24.4,19.7,M,,,,0000*1F
| Field | Example | Comments |
| Sentence ID | $GPGGA |
| UTC Time | 092204.999 | hhmmss.sss |
| Latitude | 4250.5589 | ddmm.mmmm |
| N/S Indicator | S | N = North, S = South |
| Longitude | 14718.5084 | dddmm.mmmm |
| E/W Indicator | E | E = East, W = West |
| Position Fix | 1 | 0 = Invalid, 1 = Valid SPS, 2 = Valid DGPS, 3 = Valid PPS |
| Satellites Used | 04 | Satellites being used (0-12) |
| HDOP | 24.4 | Horizontal dilution of precision |
| Altitude | 19.7 | Altitude in meters according to WGS-84 ellipsoid |
| Altitude Units | M | M = Meters |
| Geoid Seperation | | Geoid seperation in meters according to WGS-84 ellipsoid |
| Seperation Units | | M = Meters |
| DGPS Age | | Age of DGPS data in seconds |
| DGPS Station ID | 0000 | |
| Checksum | *1F | |
| Terminator | CR/LF | |
$GPGLL Sentence (Position)
Example (signal not acquired): $GPGLL,0000.0000,N,00000.0000,E,235947.000,V*2D
Example (signal acquired): $GPGLL,4250.5589,S,14718.5084,E,092204.999,A*2D
| Field | Example | Comments |
| Sentence ID | $GPGLL |
| Latitude | 4250.5589 | ddmm.mmmm |
| N/S Indicator | S | N = North, S = South |
| Longitude | 14718.5084 | dddmm.mmmm |
| E/W Indicator | E | E = East, W = West |
| UTC Time | 092204.999 | hhmmss.sss |
| Status | A | A = Valid, V = Invalid |
| Checksum | *2D | |
| Terminator | CR/LF | |
$GPGSA Sentence (Active satellites)
Example (signal not acquired): $GPGSA,A,1,,,,,,,,,,,,,0.0,0.0,0.0*30
Example (signal acquired): $GPGSA,A,3,01,20,19,13,,,,,,,,,40.4,24.4,32.2*0A
| Field | Example | Comments |
| Sentence ID | $GPGSA | |
| Mode 1 | A | A = Auto 2D/3D, M = Forced 2D/3D |
| Mode 1 | 3 | 1 = No fix, 2 = 2D, 3 = 3D |
| Satellite used 1 | 01 | Satellite used on channel 1 |
| Satellite used 2 | 20 | Satellite used on channel 2 |
| Satellite used 3 | 19 | Satellite used on channel 3 |
| Satellite used 4 | 13 | Satellite used on channel 4 |
| Satellite used 5 | | Satellite used on channel 5 |
| Satellite used 6 | | Satellite used on channel 6 |
| Satellite used 7 | | Satellite used on channel 7 |
| Satellite used 8 | | Satellite used on channel 8 |
| Satellite used 9 | | Satellite used on channel 9 |
| Satellite used 10 | | Satellite used on channel 10 |
| Satellite used 11 | | Satellite used on channel 11 |
| Satellite used 12 | | Satellite used on channel 12 |
| PDOP | 40.4 | Position dilution of precision |
| HDOP | 24.4 | Horizontal dilution of precision |
| VDOP | 32.2 | Vertical dilution of precision |
| Checksum | *0A | |
| Terminator | CR/LF | |
$GPGSV Sentence (Satellites in view)
Example (signal not acquired): $GPGSV,1,1,01,21,00,000,*4B
Example (signal acquired): $GPGSV,3,1,10,20,78,331,45,01,59,235,47,22,41,069,,13,32,252,45*70
| Field | Example | Comments |
| Sentence ID | $GPGSV | |
| Number of messages | 3 | Number of messages in complete message (1-3) |
| Sequence number | 1 | Sequence number of this entry (1-3) |
| Satellites in view | 10 | |
| Satellite ID 1 | 20 | Range is 1-32 |
| Elevation 1 | 78 | Elevation in degrees (0-90) |
| Azimuth 1 | 331 | Azimuth in degrees (0-359) |
| SNR 1 | 45 | Signal to noise ration in dBHZ (0-99) |
| Satellite ID 2 | 01 | Range is 1-32 |
| Elevation 2 | 59 | Elevation in degrees (0-90) |
| Azimuth 2 | 235 | Azimuth in degrees (0-359) |
| SNR 2 | 47 | Signal to noise ration in dBHZ (0-99) |
| Satellite ID 3 | 22 | Range is 1-32 |
| Elevation 3 | 41 | Elevation in degrees (0-90) |
| Azimuth 3 | 069 | Azimuth in degrees (0-359) |
| SNR 3 | | Signal to noise ration in dBHZ (0-99) |
| Satellite ID 4 | 13 | Range is 1-32 |
| Elevation 4 | 32 | Elevation in degrees (0-90) |
| Azimuth 4 | 252 | Azimuth in degrees (0-359) |
| SNR 4 | 45 | Signal to noise ration in dBHZ (0-99) |
| Checksum | *70 | |
| Terminator | CR/LF | |
$GPRMC Sentence (Position and time)
Example (signal not acquired): $GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*1D
Example (signal acquired): $GPRMC,092204.999,A,4250.5589,S,14718.5084,E,0.00,89.68,211200,,*25
| Field | Example | Comments |
| Sentence ID | $GPRMC | |
| UTC Time | 092204.999 | hhmmss.sss |
| Status | A | A = Valid, V = Invalid |
| Latitude | 4250.5589 | ddmm.mmmm |
| N/S Indicator | S | N = North, S = South |
| Longitude | 14718.5084 | dddmm.mmmm |
| E/W Indicator | E | E = East, W = West |
| Speed over ground | 0.00 | Knots |
| Course over ground | 0.00 | Degrees |
| UTC Date | 211200 | DDMMYY |
| Magnetic variation | | Degrees |
| Checksum | *25 | |
| Terminator | CR/LF | |
$GPVTG Sentence (Course over ground)
Example (signal not acquired): $GPVTG,,T,,M,,N,,K*4E
Example (signal acquired): $GPVTG,89.68,T,,M,0.00,N,0.0,K*5F
| Field | Example | Comments |
| Sentence ID | $GPVTG | |
| Course | 89.68 | Course in degrees |
| Reference | 89.68 | T = True heading |
| Course | | Course in degrees |
| Reference | 89.68 | M = Magnetic heading |
| Speed | 0.00 | Horizontal speed |
| Units | N | N = Knots |
| Speed | 0.00 | Horizontal speed |
| Units | K | K = KM/h |
| Checksum | *5F | |
| Terminator | CR/LF | |
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