Cheers,
I'm off the study of this topic, but can offer a clue. I have a
ham program which permits the use of the NMEA protocol. This worthy
application includes a series "statements" which allow the GPS receiver to
calculate your position, and other qualities. However, it was designed as
marine program, wherein ships don't usually change route every few minutes
as our aircraft might. Therefore, it is missing a sentence which allows for
setting up a series of legs on a flight. This is either RMB or RMC (I think
the former - experts please correct). I have failed to discover a device -
other than the multi-buck aircraft navs - which include this vital sentence.
For clarity why not consult Wikipedia, which explains it far better than I
what the sentences are. It's marvellous - and shouldn't leave anyone 'cold'.
hey,
Ferg
|