Format for a NEMA Sentence
$Talker ID + Sentence ID + Data
- Every NMEA sentence begins with a '$' sign.
- Talker ID is used to identify from which satellite system data is comming from
- It is two characters long. Examples below:
- GP - GPS (USA)
- GL - GLONASS (Russia)
- GI - NavIC/IRNSS (India)
- GN - GNSS
NOTE: GN is used when cobination of multiple satelitte system is used.
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Sentence ID is define what type of sentence it is and what data it contains.
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It is three characters long. Examples beow:
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GGA - Time, position and fix type data
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GLL - Latitude, longitude, UTC time of position fix and status
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GSA - GPS receiver operating mode, satellites used in the position solution, and DOP values
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GSV - Number of GPS satellites in view satellite ID numbers, elevation, azimuth, & SNR values
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RMC - Time, date, position, course and speed data