Nmea 0183 Sentences Updated -

| Sentence | Description | Typical Talker | Key Data Fields | |----------|-------------|----------------|------------------| | | Global Positioning System Fix Data | GP, GN | Time, Lat, Lon, Fix quality, # satellites, HDOP, altitude, geoidal separation | | RMC | Recommended Minimum Specific GNSS Data | GP, GN | Time, Status (A/V), Lat, Lon, Speed over ground, Course, Date, Magnetic variation | | GSA | GNSS DOP and Active Satellites | GP, GN | Mode (2D/3D), Satellites used (PRNs), PDOP, HDOP, VDOP | | GSV | Satellites in View | GP, GN | # satellites, PRN, elevation, azimuth, SNR (repeated for up to 4 satellites per sentence) | | VTG | Course Over Ground & Ground Speed | GP, GN | True course, Magnetic course, Speed in knots, Speed in km/h | | ZDA | Time & Date (UTC) | GP, GN | UTC time, day, month, year, local zone hours/minutes | | HDT | Heading – True | HE, HC | Heading in degrees true | | HDM | Heading – Magnetic | HC | Heading in degrees magnetic | | ROT | Rate of Turn | HE | Rate of turn (degrees/min), status (A/V) | | DPT | Depth of Water | SD | Depth (meters), offset from transducer | | DBT | Depth Below Transducer | SD | Depth in feet, meters, fathoms | | MTW | Mean Temperature of Water | MT | Degrees Celsius | | MWV | Wind Speed and Angle | VW | Wind angle (relative/true), reference (R/T), speed (knots/m/s), status | | VHW | Water Speed and Heading | VW | Heading true/magnetic, speed through water (knots) | | APB | Autopilot Sentence "B" | EC, GP | Cross-track error, arrival status, bearing to waypoint | | RMB | Recommended Minimum Navigation Info | GP | Cross-track error, waypoint ID, range, bearing, velocity | | BOD | Bearing (Origin to Destination) | GP | Bearing true/magnetic to destination waypoint | | BWC | Bearing & Distance to Waypoint | GP | UTC time, bearing true/mag, distance (nm), waypoint ID | | GLL | Geographic Position (Lat/Lon) | GP | Latitude, longitude, UTC time, status (A/V) | | TLL | Target Latitude/Longitude | RA, AI | Target name, lat, lon, time, status | | TTM | Tracked Target Message | RA | Target number, range, bearing, course, speed, CPA/TCPA | | ALR | Alarm/Alert Sentence | II | Time, unique ID, alarm condition, description | | TXT | Text Transmission | II, GP | Text messages (e.g., device warnings) | | RTE | Route Message | GP | Route name, waypoint list | | WPL | Waypoint Location | GP | Waypoint ID, latitude, longitude |

Encoded AIS position report (requires decoding per ITU-R M.1371). nmea 0183 sentences

The checksum is the XOR (exclusive OR) of all bytes between $ (excluded) and * (excluded). | Sentence | Description | Typical Talker |

An NMEA sentence is a string of ASCII characters transmitted serially (traditionally at 4800 baud). Each sentence acts as a distinct packet of information. Because the data is sent as plain text, it is human-readable and easy to parse with microcontrollers (like Arduino or Raspberry Pi) or PC software. Each sentence acts as a distinct packet of information

Despite the emergence of the newer NMEA 2000 standard, NMEA 0183 remains essential on millions of vessels due to its simplicity, human-readability, and reliability in life-saving applications like connecting GPS receivers to VHF radios for emergency distress signals. The Anatomy of an NMEA 0183 Sentence