SkyTraq PX1120S - Page 12

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SkyTraq Technology, Inc. Preliminary Draft www.skytraq.com.tw
The formats of the supported NMEA messages are described as follows:
GGA – Global Positioning System Fix Data
Time, position and fix related data for a GPS receiver.
Structure:
$GPGGA,hhmmss.sss,ddmm.mmmmm,a,dddmm.mmmmm,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:
$GNGGA,052315.000,2447.09094,N,12100.52369,E,2,12,0.6,97.9,M,19.6,M,,0000*6B<CR><LF>
Field
Name
Example
Description
1
UTC Time
025315.000
UTC of position in hhmmss.sss format, (000000.000 ~ 235959.999)
2
Latitude
2447.09094
Latitude in ddmm.mmmm mformat
Leading zeros transmitted
3
N/S Indicator
N
Latitude hemisphere indicator, ‘N’ = North, ‘S’ = South
4
Longitude
12100.52369
Longitude in dddmm.mmmmm format
Leading zeros transmitted
5
E/W Indicator
E
Longitude hemisphere indicator, ‘E’ = East, ‘W’ = West
6
Quality Indicator
2
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
12
Number of satellites in use, (00 ~ 12)
8
HDOP
0.6
Horizontal dilution of precision, (0.0 ~ 99.9)
9
Altitude
97.9
mean sea level (geoid), (-9999.9 ~ 17999.9)
10
Geoidal Separation
19.6
Geoidal separation in meters
11
Age pf Differential
GPS data
Age of Differential GPS data
NULL when DGPS not used
12
DGPS Station ID
0000
Differential reference station ID, 0000 ~ 1023
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Checksum
6B