I'm writing an Android app that reads and parses NMEA sentences from GPS receiver and using a Nexus S phone for tests.
I'm getting GPGGA, GPGSV, GPGSA and GPRMC sentences that are pretty common and very well documented, but in addition, I'm getting next sentences and I'cant find any info about them:
PGLOR, GNGSA, QZGSA
Where I can find some docs about those sentences format?
The $GN-prefix is usually used when the sentence is formed using several satellite constellations (so far usually Glonass and GPS are the viable options). The $QZ-prefix is a little more unclear but I assume that it is for the Japanese QZSS-satellite constellation.
The rest of the sentence after the prefix is standard NMEA 0183 and contains what the normal GSA-sentence would contain.
The $PGLOR is probably used to produce information and / or configure the locationing chip. Or something similarly uninteresting.
What's really interesting is that Nexus S seems to have a Multi GNSS locationing chip.
Further information here