Atlas PT Technical Manual
39
11.
ATLAS PT
Messages
The ATLAS PT
sends and receives messages in the PRAVE format. PRAVE is a
proprietary protocol developed by Raveon. Use 38400 bps, 8 data bits, no parity and
one stop bit (8N1) for standard PRAVE data. See below for PRAVE formatting.
11.1
$GPGSV Satellites In View
When this message comes out of the
Atlas SM
, it identifies the number of satellites its
internal GPS has in view. Up to 3 satellites may be reported in one message. The
ATLAS PT
typically does not report any satellite information other than the Number of
Satellites in view.
$GPGSV,1,2,3,4,5,6,7 * cks
Field
Usage
Comments
$
GPGSV
Number of SVs in view, PRN numbers, elevation,
azimuth & SNR values.
1
Count
Total number of messages of this type in this cycle
2
Message number
This message’s number
3
Number of sats
The total number of satellites in view.
4
PRN
Satellite number.
5
Elevation
Elevation in degrees, 90 maximum
6
Azimuth
Azimuth, degrees from true north, 000 to 359
7
SNR
Signal-to-noise ratio for this sat.
cks
NMEA checksum
11.2
$GPWPL Waypoint Location
The waypoint location sentence is used by GPS receivers and plotters in different ways,
often to share waypoint data or to show waypoints on-screen.
$GPWPL,1,2,3,4,5,6 * cks
Field
Usage
Comments
$
GPWPL
Waypoint Location Message Header
1
Lat
Latitude of the point.
2
N/S
North or South.
One character.
