EverMore Technology Inc.
2F, No.7, R&D Road 1, Science-Based Industrial Park, Hsinchu, Taiwan, 310, R.O.C.
http://www.emt.com.tw
13
4.1.2 GGA – Global Positioning System Fix Data
Purpose
Output time, position and position-fix related data.
Format
$GPGGA,hhmmss.sss,ddmm.mmmm,a,dddmm.mmmm,a,x,xx,xx.x,xxxxx.x,M,,M,xxx,xxxx*CS
Example
$GPGGA,153639.385,2446.5243,N,12100.1494,E,1,08,00.9,00163.8,M,,M,,*74
Field
Name
Example
Unit
Description
1
Message ID
$GPGGA
GGA protocol header
2
UTC Time
153639.385
hhmmss.sss
hour, minute, sec & decimal sec
000000.000 ~ 235959.999
Leading zeros transmitted
3
Latitude
2446.5243
ddmm.mmmm
degree, minute & decimal minute
Leading zeros transmitted
4
N/S Hemisphere Indicator
N
a, N=north or S=south
5
Longitude
12100.1494
dddmm.mmmm
degree, minute & decimal minute
Leading zeros transmitted
6
E/W Hemisphere Indicator
E
a, E=east or W=west
7
GPS Position Fix Indicator
1
x
0 = no position fix or invalid
1 = valid fix, SPS mode
2 = valid fix, DGPS, SPS mode
8
# of Satellites Used
08
xx, 00 ~ 12,
Leading zeros transmitted
9
HDOP
00.9
xx.x, Leading zeros transmitted
10 MSL Altitude
00163.8
Meter xxxxx.x
MSL altitude = WGS-84 ellipsoid
height minus geoidal separation.
Currently this field is WGS-84
ellipsoid height
Leading zeros transmitted
11 Unit of Altitude
M
Meter
12 Geoid Separation
Not supported
13 Unit of Geoid Separation
M
Meter
14 Age of Differential GPS Data
second xxx
Time in seconds since last RTCM
SC-104 Type-1 or Type-9 update.
Null when DGPS is not used
15 Differential Reference
Station ID
xxxx, 0000 ~ 1023
Leading zeros transmitted
Null when DGPS is not used
16 Checksum
*74
