PilotAware
British Forum => General Discussion => Topic started by: Paul_Sengupta on June 10, 2016, 09:54:14 am
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Quick question, under GPS on the home page, it has "GPS fix (SPS)" and "Mode=3D". I take it SPS means Standard Positioning Service? Is there an indication of whether WAAS/EGNOS is being received? I seen to remember it's an easy spot, a 1 in a certain NMEA message means non WAAS, a 2 means WAAS. It would be nice to have WAAS indicated if only for setting how much to trust the GPS altitude.
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Hi Paul
I took a quick look and could not see anything obvious, if you can point me at a doc reerencing the message and the field which indicates this, it could be added
Thx
Lee
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I believe it's the number "2" in the message highlighted in this post:
http://forum.pilotaware.com/index.php/topic,201.msg3639.html#msg3639 (http://forum.pilotaware.com/index.php/topic,201.msg3639.html#msg3639)
http://forum.pilotaware.com/index.php/topic,201.msg3614.html#msg3614 (http://forum.pilotaware.com/index.php/topic,201.msg3614.html#msg3614)
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Hi Paul
in which case it is already implemented, this is the text that gets printed
0 "Invalid",
1 "GPS fix (SPS)",
2 "DGPS fix",
3 "PPS fix",
4 "Real Time Kinematic",
5 "Float RTK",
6 "estimated (dead reckoning) (2.3 feature)",
7 "Manual input mode",
8 "Simulation mode"
from here
GGA - essential fix data which provide 3D location and accuracy data.
$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47
Where:
GGA Global Positioning System Fix Data
123519 Fix taken at 12:35:19 UTC
4807.038,N Latitude 48 deg 07.038' N
01131.000,E Longitude 11 deg 31.000' E
1 Fix quality: 0 = invalid
1 = GPS fix (SPS)
2 = DGPS fix
3 = PPS fix
4 = Real Time Kinematic
5 = Float RTK
6 = estimated (dead reckoning) (2.3 feature)
7 = Manual input mode
8 = Simulation mode
08 Number of satellites being tracked
0.9 Horizontal dilution of position
545.4,M Altitude, Meters, above mean sea level
46.9,M Height of geoid (mean sea level) above WGS84
ellipsoid
(empty field) time in seconds since last DGPS update
(empty field) DGPS station ID number
*47 the checksum data, always begins with *
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Ah, right, thanks, just that I haven't seen DGPS fix but I haven't actually looked while out in the open or in the air. I've just noticed that the altitude seems to be pretty much spot on when I'm flying.
Good to know, I'll watch out for it now!
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I've just tried my PAW out in the garden with the GPS on a USB extension up on the fence, facing south.
I do indeed get "DGPS" displayed on the homepage. So to answer my original question, yes, there is an indication if WAAS/EGNOS is being received, it's this. :)