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Message number
2
Number of sats
3
4
Elevation
5
6
7
cks
13.3.
$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
$ GPWPL
1
2
3
4
WP Name
5
cks
When the ATLAS PL is set to GPS 4 mode of operation, it will output this message
every time it receives a position report from another ATLAS PL transponder.
Within the WPL message, is the latitude, longitude, and "waypoint ID". In the
waypoint ID field, the ATLAS PL puts the ID of the RV-M7 that transmitted its
position.
For example, if a ATLAS PL receives a position report from ID 0003 located at
4917.16N , 12310.64W it sends out the following message.
$GPWPL,4917.16,N,12310.64,W,3*65
The lat/lon is sent using the dddmm.mm format, where ddd is the degrees, and
mm.mmmm is the decimal minutes. There is no sign to these numbers.
GPS 4 mode with the $GPWPL message is the most common way of using the
ATLAS PL with a hand-held or mobile GPS. Most any GPS with a serial-data input
will accept the $GPWPL message, and put an icon on its screen, with a label
showing the ID of the RV-M7 at that position.
Some GPS display have an issue when a new position report is received. Most will
move the waypoint to the new location, but some re-draw a new waypoint at the
new position, and leave the old waypoint in place.
To help make the waypoints easier to read, the ATLAS PL may be programmed
with an ID prefix, using the PREFIX vvvv command. The default is a capitol letter
M7 PL Technical Manual
This message's number
The total number of satellites in view.
PRN
Satellite number.
Elevation in degrees, 90 maximum
Azmuth
Azimuth, degrees from true north, 000 to 359
SNR
Signal-to-noise ratio for this sat.
NMEA checksum
Usage
Comments
Waypoint Location Message Header
Lat
Latitude of the point.
N/S
North or South.
Lon
Longitude of the position
E/W
East or west. One character.
The ID of the unit that transmitted its position plus any user-set
prefix.
NMEA checksum
One character.
42
Raveon Technologies Corp.
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