NMEA 0183 GGA Parser
Decode GNSS NMEA GGA sentences into readable position, fix quality, satellite count and HDOP.
Input
Result
Understanding NMEA 0183 sentences
NMEA 0183 is the standard data protocol for marine and GNSS electronics. Every GPS receiver outputs NMEA sentences as comma-separated ASCII strings starting with "$GP" (GPS only) or "$GN" (multi-constellation) and ending with a checksum.
The GGA sentence is the most commonly decoded message because it contains the full 3D position fix: UTC time, latitude, longitude, altitude, fix quality indicator, number of satellites used, and HDOP. This parser extracts all fields and shows them in a readable format.
nmea_parse.formula_title
nmea_parse.formula_explain
nmea_parse.factors_title
- nmea_parse.factor_1
- nmea_parse.factor_2
- nmea_parse.factor_3
- nmea_parse.factor_4
- nmea_parse.factor_5
- nmea_parse.factor_6
- nmea_parse.factor_7
nmea_parse.dop_types_title
- nmea_parse.dop_1 \u2014
- nmea_parse.dop_2 \u2014
- nmea_parse.dop_3 \u2014
- nmea_parse.dop_4 \u2014
- nmea_parse.dop_5 \u2014
Typical uses of NMEA parsing
Debugging GNSS receivers: verify the receiver outputs correct data before integrating with field software.
Custom mapping applications: parse real-time sentences to plot positions on maps.
Quality monitoring: extract fix quality and HDOP to filter low-quality epochs automatically.
Logger analysis: decode archived NMEA logs for post-mission accuracy analysis.
Frequently asked questions
What is the difference between $GP and $GN sentences?
$GP means the data comes from GPS only. $GN indicates a multi-constellation solution (GPS + GLONASS + Galileo + BeiDou combined).
How do I verify the NMEA checksum?
The two hex characters after * are the XOR of all ASCII characters between $ and *. Valid receivers always include a correct checksum.
Does this parser handle RMC or VTG sentences?
Currently only GGA is supported. We plan to add GSA, RMC, VTG, and GSV support in future updates.
nmea_parse.faq_4_q
nmea_parse.faq_4_a
Related topics
See our glossary entries on GNSS, RTK, GDOP, and GPS for more background.