GGA - Global Positioning System Fix Data
Time, Position and fix related data for a GPS receiver.

        1         2       3 4        5 6 7  8   9  10 |  12 13  14   15
        |         |       | |        | | |  |   |   | |   | |   |    |
 $--GGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh<CR><LF>

 Field Number:
  1) Universal Time Coordinated (UTC)
  2) Latitude
  3) N or S (North or South)
  4) Longitude
  5) E or W (East or West)
  6) GPS Quality Indicator,
     0 - fix not available,
     1 - GPS fix,
     2 - Differential GPS fix
     (values above 2 are 2.3 features)
     3 = PPS fix
     4 = Real Time Kinematic
     5 = Float RTK
     6 = estimated (dead reckoning)
     7 = Manual input mode
     8 = Simulation mode
  7) Number of satellites in view, 00 - 12
  8) Horizontal Dilution of precision (meters)
  9) Antenna Altitude above/below mean-sea-level (geoid) (in meters)
 10) Units of antenna altitude, meters
 11) Geoidal separation, the difference between the WGS-84 earth
     ellipsoid and mean-sea-level (geoid), "-" means mean-sea-level
     below ellipsoid
 12) Units of geoidal separation, meters
 13) Age of differential GPS data, time in seconds since last SC104
     type 1 or 9 update, null field when DGPS is not used
 14) Differential reference station ID, 0000-1023
 15) Checksum