GPS NMEA

$GPGGA

Global Positioning System Fix Data

Example:

|Structure |Description |Symbol |Example |
|:--- |:--- |:--- |:--- |
|$GPGGA |Log header | |$GPGGA |
|utc |UTC time status of position (hours/minutes/seconds/ decimal seconds) |hhmmss.ss |202134.00 |
|lat |Latitude (DDmm.mm) |llll.ll |5106.9847 |
|lat dir |Latitude direction (N=North, S=South) |a |N |
|lon |Longitude (DDDmm.mm) |yyyyy.yy |11402.2986 |
|lon dir |Longitude direction(E=East, W=West) |a |W |
|quality |refer to "GPS Quality Indicators" | x |1 |
|# sats |Number of satelites in use. May be different to the number in view |xx |10 |
|hdop |Horizontal dilution of precision | x.x |1.0 |
|alt |Antenna altitude above/below mean sea level |x.x |1062.22 |
|a-units |Units of antenna altitude (M=metres) |M |M|
|undulation |Undulation - the relationship between the geoid and the WGS84 ellipsiod |x.x |-16.271 |
|u-units |Units of undulation(M=metres) |M |M |
|age |Age of correction data (in seconds). The maximum age reported here is limited to 99 sec. |xx |(empty when no differential data is present) |
|stn ID |Differential base station ID |xxx |(empty when no differential data is present) |
|\*xx |Checksum |\*hh |\*48 |
|{CR}{LF} |Sentence terminator | |{CR}{LF} |

GPS Quality Indicators:

|Indicator |Description |
|:--- |:--- |
|0 |Fix not available or invalid |
|1 |Single point<br/>Converging PPP(TerraStar-L) |
|2 |Pseudo-range differential<br/>Converged PPP(TerraStar-L)<br/>Converging PPP(TerraStar-C, TerraStar-C PRO, TerraStar-X) |
|4 |RTK fixed ambiguity solution |
|5 |RTK floating ambiguity solution<br/>Converged PPP(TerraStar-C, TerraSTar-C PRO, TerraSTar-X) |
|6 |Dead reckoning mode |
|7 |Manual input mode (fixed position) |
|8 |Simulator mode |
|9 |WAAS(SBAS) |

## $GPGLL
Geographic position

Example:

$GPGLL,5107.0013414,N,11402.3279144,W,205412.00,A,A*73

|Structure |Description |Example |
|:--- |:--- |:--- |
|$GPGLL |Log header |$GPGLL |
|lat |Latitude (DDmm.mm) |5106.7198674 |
|lat dir |Latitude direction (N = North, S = South) |N |
|lon |Longitude (DDDmm.mm) |11402.3587526 |
|lon dir |Longitude direction (E = East, W = West) |W |
|utc |UTC time status of position (hours/minutes/seconds/decimal seconds) |220152.50 |
|data status |Data status: A = Data valid, V = Data invalid |A |
|mode ind |Positioning system mode indicator, see Table: NMEA Positioning System Mode Indicator |A |
|\*xx |Check sum |*1B |
|{CR}{LF} |Sentence terminator |{CR}{LF} |

NMEA Positioning System Mode Indicator:

|Mode |Indicator |
|:--- |:--- |
|A |Autonomous |
|D |Differential |
|E |Estimated (dead reckoning) mode |
|M |Manual input |
|N |Data not valid |

## $GPGSA
GPS DOP and active satellites

Example: 

$GPGSA,M,3,17,02,30,04,05,10,09,06,31,12,,,1.2,0.8,0.9*35

|Structure |Description |Symbol |Example |
|:--- |:--- |:--- |:--- |
|$GPGSA |Log header | |$GPGSA |
|mode MA |A = Automatic 2D/3D<br/>M = Manual, forced to operate in 2D or 3D |M |M |
|mode 123 |Mode: 1 = Fix not available; 2 = 2D; 3 = 3D |x |3 |
|prn |PRN numbers of satellites used in solution (null for unused fields), total of 12 fields<br/><li><ul>GPS = 1 to 32</ul><ul>SBAS = 33 to 64 (add 87 for PRN number)</ul><ul>GLO = 65 to 96</ul></li>|xx,xx,..... |18,03,13,25,16,24,12,20,,,, |
|pdop |Position dilution of precision |x.x |1.5 |
|hdop |Horizontal dilution of precision |x.x |0.9 |
|vdop |Vertical dilution of precision |x.x |1.2 |
|system ID |GNSS system ID. GPS System ID = 1, L1 C/A Signal ID = 1 | | |
|\*xx |Checksum |\*hh |\*3F |
|{CR}{LF} |Sentence terminator |{CR}{LF} |

## $GPGSV
GPS Satellites in View

Example:

$GPGSV,3,1,11,18,87,050,48,22,56,250,49,21,55,122,49,03,40,284,4778 $GPGSV,3,2,11,19,25,314,42,26,24,044,42,24,16,118,43,29,15,039,427E $GPGSV,3,3,11,09,15,107,44,14,11,196,41,07,03,173,4D $GLGSV,2,1,06,65,64,037,41,66,53,269,43,88,39,200,44,74,25,051,64 $GLGSV,2,2,06,72,16,063,35,67,01,253,*66

|Structure |Description |Symbol |Example |
|:--- |:--- |:--- |:--- |
|$GPGSV |Log header | |$GPGSV |
|# msgs |Total number of messages (1-9) |x |3 |
|msg # |Message number (1-9) |x |1 |
|# sats |Total number of satellites in view. May be different than the number of satellites in use |xx |09 |
|prn |Satellites PRN number<br/><li><ul>GPS = 1 to 32</ul><ul>Galileo = 1 to 36</ul><ul>BeiDou = 1 to 63</ul><ul>NavIC = 1 to 14</ul><ul>QZSS = 1 to 10</ul><ul>SBAS = 33 to 64 (add 87 for PRN#s)</ul><ul>GLONASS = 65 to 96</ul></li> |xx |03 |
|elev |Elevation, degree, Max 90 |xx |51 |
|azimuth |Azimuth, degree True, 000 to 359 |xxx |140 |
|SNR |SNR (C/No) 00-99dB, null when not tracking |xx |42 |
|... |Next satellite PRN number, elev, azimuth, SNR | | |
|system ID |GNSS system ID | | |
|\*xx |Checksum |\*hh |\*72 |
|{CR}{LR} |Sentence terminator | |{CR}{LR} |

## $GPRMC
GPS specific information

Example:

$GPRMC,144326.00,A,5107.0017737,N,11402.3291611,W,0.080,323.3,210307,0.0,E,A*20 ```

Structure	Field Description	Symbol	Example
$GPRMC	Log header		$GPRMC
utc	UTC of position	hhmmss.ss	144326.00
pos status	Position status (A = data valid, V = data invalid)	A	A
lat	Latitude (DDmm.mm)	llll.ll	5107.0017737
lat dir	Latitude direction: (N = North, S = South)	a	N
lon	Longitude (DDDmm.mm)	yyyyy.yy	11402.3291611
lon dir	Longitude direction: (E = East, W = West)	a	W
speed Kn	Speed over ground, knots	x.x	0.080
track true	Track made good, degrees True	x.x	323.3
date	Date: dd/mm/yy	xxxxxx	210307
mag var	Magnetic variation, degrees	Note that this field is the actual magnetic variation and will always be positive. The direction of the magnetic variation is always positive.	x.x	0.0
var dir	Magnetic variation direction E/W	Easterly variation (E) subtracts from True course.
Westerly variation (W) adds to True course.	a	E
mode ind	Positioning system mode indicator, see Table: NMEA Positioning System Mode Indicator	a	A
*xx	Checksum	*hh	*20
{CR}{LR}	Sentence terminator		{CR}{LR}

NMEA Positioning System Mode Indicator:

Mode	Indicator
A	Autonomous
D	Differential
E	Estimated (dead reckoning) mode
M	Manual input
N	Data not valid