TomasGPS » 17 Rgs 2009, 12:18
GGA pozicijos žinutėje jau yra informacija kokia yra matavimo kokybe: RTK, DGPS, RTK float, Navigated ir panašiai.
Štai GGA žinutės aprašymas:
NMEA GGA Definition
The NMEA GGA string is a standard format for transmission of geographic coordinates and dilution of precision information.
Format
Content
$xxGGA,
Either GPGGA for NMEA message from GPS system, GLGGA for GLONASS or GNGGA for GPS&GLONASS. Header, incl . Talker ID, message sent from the Receiver
hhmmss.ss ,
UTC time of Position
llll.ll ,
Latitude
a,
Hemisphere “N”/“S”
yyyyy.yy ,
Longitude
a,
“E”/“W”
x,
GPS Quality Indicator
0 = fix not available or invalid
1 = No Realtime position, navigation fix
2 = Realtime position, ambiguities not fixed
(3 = PPS solution, not used by Leica rover)
4 = Realtime position, ambiguities fixed
(5 = Realtime position, float ambiguities, not used by Leica rover)
6 = Estimated (dead reckoning) mode
xx ,
Number of satellites in use, 00-12
x.x ,
HDOP
x.x ,
Antenna altitude above/below mean sea level. Note, if no orthometric height is available the local ellipsoidal height will be exported.
The geoid separation can be configured in the Site Properties: Antenna.
M,
Units of altitude meters (fixed text “M”)
x.x ,
Geoid separation
M,
Units of geoid separation meters (fixed text “M”).
x.x ,
Age of differential GPS data, null when DGPS not used
xxxx
Differential Reference Station ID, 0000-1023
* hh
Checksum
<CR>
Carriage Return
< LF >
Line Feed
Example:
$GPGGA,125622.00,4724.5287493,N,00937.0830581,E,4,07,1.200,474.375,M,0.000,M,,0000*52
$GLGGA,125622.00,4724.5287493,N,00937.0830581,E,4,02,1.200,474.375,M,0.000,M,,0000*52
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