Hi,
Is there any particular reason why the $GPRMC message
generated for Atlas protocol only has a 'dummy'
magnetic variation, '0.000,E' - in atlas.cxx,
about line 139
For example, the garmin message correctly gets the -
/environment/magnetic-variation-deg
when generating its $GPRMC message - in garmen.cxx,
lines 127-135.
I am trying to add some 'features' to Atlas, to further
aid in 'navigation', and the magnetic variation will
assist in these calculations...
The message heading given is magnetic -
/orientation/heading-deg
and the addition of the magnetic variation to the
Atlas $GPRMC message would allow the true heading
to be calculated and be used in SG geod distance
calculations, etc...
It would be as simple as duplicating the code from
the garmin.cxx, something like :-
char dir = 'E'; char magvar[10];
float magdeg = fgGetDouble("/environment/magnetic-variation-deg");
if (magdeg < 0.0) {
magdeg = -magdeg;
dir = 'W';
}
sprintf( magvar, "05.1f,%c", magdeg, dir );
then add 'magvar' to the Atlas $GPRMC message...
Of course, Atlas could have code to 'calculate' its own
magnetic variation, like that in coremag.cxx, or use the
functions from that SG library, but hope not to have to
do that... especially since I think it 'should' be part
of the $GPRMC message...
Was this just an oversight, or was there a specific reason
why it was decided that the Atlas message should only
have a 'dummy' value?
If just oversight, then the above code could serve as a
patch to atlas.cxx... when someone has the time... and that
would be very much appreciated ;=))
Regards,
Geoff.
------------------------------------------------------------------------------
Free Software Download: Index, Search & Analyze Logs and other IT data in
Real-Time with Splunk. Collect, index and harness all the fast moving IT data
generated by your applications, servers and devices whether physical, virtual
or in the cloud. Deliver compliance at lower cost and gain new business
insights. http://p.sf.net/sfu/splunk-dev2dev
_______________________________________________
Flightgear-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
