UniTraQ International Corp.
RoHS compliance
2007, Version 1.1
6
Eastern Star 7 series GT-3731R
GPS Receiver
9. APPROVED NMEA MESSAGE
The serial interface protocol is based on the National Marine Electronics Association’s NMEA 0183 ASCII
interface specification. This standard is fully define in “NMEA 0183, Version 3.01” The standard may be
obtained from NMEA,
www.nmea.org
9.1 GGA – GLOBAL POSITIONING SYSTEM FIX DATA
Time, position and fix related data for a GPS receiver.
Structure:
$GPGGA,hhmmss.sss,ddmm.mmmm,a,dddmm.mmmm,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh<CR><LF>
1 2 3 4 5 6 7 8 9 10 11 12 13
Example:
$GPGGA,060932.448,2447.0959,N,12100.5204,E,1,08,1.1,108.7,M,,,,0000*0E<CR><LF>
Field Name
Example
Description
1
UTC Time
060932.448
UTC of position in hhmmss.sss format, (000000.00 ~
235959.99)
2
Latitude
2447.0959
Latitude in ddmm.mmmm format
Leading zeros transmitted
3
N/S Indicator
N
Latitude hemisphere indicator, ‘N’ = North, ‘S’ = South
4
Longitude
12100.5204
Longitude in dddmm.mmmm format
Leading zeros transmitted
5
E/W Indicator
E
Longitude hemisphere indicator, 'E' = East, 'W' = West
6 GPS
quality
indicator
1
GPS quality indicator
0: position fix unavailable
1: valid position fix, SPS mode
2: valid position fix, differential GPS mode
3: GPS PPS Mode, fix valid
4: Real Time Kinematic. System used in RTK mode with
fixed integers
5: Float RTK. Satellite system used in RTK mode. Floating
integers
6: Estimated (dead reckoning) Mode
7: Manual Input Mode
8: Simulator Mode
7
Satellites Used
08
Number of satellites in use, (00 ~ 12)
8 HDOP
1.1
Horizontal
dilution
of precision, (00.0 ~ 99.9)
9
Altitude
108.7
mean sea level (geoid), (-9999.9 ~ 17999.9)
10
Geoid Separation
Geoid separation in meters according to WGS-84 ellipsoid
(-999.9 ~ 9999.9)
11
DGPS Age
Age of DGPS data since last valid RTCM transmission in
xxx format (seconds)
NULL when DGPS not used
12
DGPS Station ID
0000
Differential reference station ID, 0000 ~ 1023
NULL when DGPS not used
13 Checksum
0E
Note:
The checksum field starts with a ‘*’ and consists of 2 characters representing a hex number. The
checksum is the exclusive OR of all characters between ‘$’ and ‘*’.
