NMEA-0183 Sentences for GPS Receivers

1 Introduction

The National Marine Electronics Association (NMEA) has a standard for the formatting of Global Positioning System (GPS) information. Some of the standard NMEA-0183 "sentences" include:

AAM	Waypoint arrival alarm
APA	Autopilot format A
APB	Autopilot format B
BOD	Bearing, origin to destination
BWC	Bearing and distance to waypoint, great circle
BWR	Bearing and distance to waypoint, rhumb line (overridden by BWC if available)
DBT	Depth below transducer
DPT	Depth of water
GGA	Global Positioning System Fix Data
GLL	Geographic position, latitude and longitude (and time)
GSA	GPS DOP and active satellites
GSV	Satellites in view
HDM	Heading, magnetic north
HDT	Heading, true north
HSC	Steer to heading
MTW	Mean water temperature
RMB	Recommended minimum navigation info when dest. waypoint is active
RMC	Recommended minimum specific GPS/Transit data
VTG	Track made good and ground speed
WCV	Waypoint closure velocity
WPL	Waypoint location
XTE	Cross-track error
XTR	Cross-track error, dead reckoning (overriden by XTE if available)

Some of the proprietary "sentences" that are recognized by the NMEA include:

PGRME	Garmin Proprietary Estimated Position Error
PGRMF	Garmin Proprietary Position Fix Sentence
PGRMM	Garmin Proprietary Map Datum Sentence
PGRMV	Garmin Proprietary Velocity Sentence
PGRMZ	Garmin Proprietary Altitude Information
PRWIZCH	Rockwell Zodiac Proprietary Channel Information

Some of these sentences are described below. Note that this document should not be treated as authoratative.

2 The GGA Sentence

An example GGA sentence (without differential coorection) is shown below:


$GPGGA,210230,3855.4487,N,09446.0071,W,1,07,1.1,370.5,M,-29.5,M,,*7A

The sentence contains the following fields:

The sentence type
Current time (if available; UTC)
Latitude (in DDMM.MMM format)
Latitude compass direction
Longitude (in DDDMM.MMM format)
Longitude compass direction
Fix type (0 for no fix, 1 for GPS, 2 for DGPS)
Number of satellites used for fix
Horizontal dilution of precision
Altitude above mean sea level
Altitude units (M for meters)
Height of mean sea level above WGS-84 earth ellipsoid
Units of the above geoid seperation (M for meters)
Time since last differential correction (ignored if inactive)
Differential station ID (ignored if inactive)
The checksum validation value (in hexadecimal)

3 The GSV Sentence

Two example GSV sentences are shown below:


$GPGSV,2,1,08,02,74,042,45,04,18,190,36,07,67,279,42,12,29,323,36*77
$GPGSV,2,2,08,15,30,050,47,19,09,158,,26,12,281,40,27,38,173,41*7B

The GSV sentence contains the following fields:

The sentence type
The number of sentences in the sequence
The number of this sentence
The number of satellites
The satellite number, elevation, azimuth, and signal to noise ratio for each satellite
The checksum validation value (in hexadecimal)

4 The RMC Sentence

An example RMC sentence is shown below:


$GPRMC,210230,A,3855.4487,N,09446.0071,W,0.0,076.2,130495,003.8,E*69

The sentence contains the following fields:

The sentence type
Current time (if available; UTC)
Position status (A for valid, V for invalid)
Latitude (in DDMM.MMM format)
Latitude compass direction
Longitude (in DDDMM.MMM format)
Longitude compass direction
Speed (in knots per hour)
Heading
Date (DDMMYY)
Magnetic variation
Magnetic variation direction
The checksum validation value (in hexadecimal)