How To read Solmeta GMAX log files

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The Solmeta GMAX geotagger saves a daily log file in text format. This file is in NMEA (National Marine Electronics Association) format which is essentially text, csv (Comma Separated Values). At first sight this seems fairly impenetrable. This page describes how to read it - some of the entries are repeated, which simplifies things.

Each entry has four lines starting with $. When a photograph is taken an extra line is included which is simply "flash". the four lines start with $GPRMC, $PTNTHPR, $GPGGA and $GPGSA - these identify the type of data that the line contains. A typical entry is


$GPRMC,091444.00,A,5251.72674,N,00226.30992,W,2.129,90.25,061017,,,D*58
$PTNTHPR,85.2,N,19.5,N,-2.6,N*1F
$GPGGA,091443.00,5251.72691,N,00226.31152,W,6,12,0.75,99.5,M,48.7,M,0000,0000*77
$GPGSA,A,3,27,16,08,21,26,07,10,18,11,30,,,1.07,0.75,0.77*07

Let us examine these four rows one at a time. Call them rows A, B, C and D. The cells are separated by a comma (,) except for the checksum which is preceded by an asterisk (*) and are identified by numbers in the tables below.
A1A2A3A4A5A6A7A8A9A10A11A12A13A14
$GPRMC,091444.00,A,5251.72674,N,00226.30992,W,2.129,90.25,061017,,,D*58
B1B2B3B4B5B6B7B8
$PTNTHPR,85.2,N,19.5,N,-2.6,N*1F
C1C2C3C4C5C6C7C8C9C10C11C12C13C14C15C16
$GPGGA,091443.00,5251.72691,N,00226.31152,W,6,12,0.75,99.5,M,48.7,M,0000,0000*77
D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15D16D17D18D19
$GPGSA,A,3,27,16,08,21,26,07,10,18,11,30,,,1.07,0.75,0.77*07

Page Information

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Information compiled from various sources including APRS where a lot more information is available.
Page first published Wednesday the 11th of October, 2017
Last modified: Fri, 24 Nov 2017 09:02:04 GMT
© 2009-2018 Richard Torrens.