On Tue, 23 Oct 2012 00:43:28 -0700, Ramy wrote:

This is an important point which should have been emphasized in the
manual, or I missed it. I bet not many are aware that the bearing to the
target is based on track not heading. The error is relatively small at
lower wind speed, but can be significant in strong cross wind especially
at slow flight.

Surely this is obvious.

As any fule kno[1] a GPS receiver can only know its track vector and
record its track: it doesn't matter whether you carry it forwards,
backwards or sideways, it still correctly records its track without
having the faintest idea of which way its being pointed relative to that
track.

The FLARM depends entirely on GPS for its knowledge of its current track
vector, so it follows that it too knows nothing about its orientation
relative to your gliders fuselage or what the glider's heading might be.


[1] nigel molesworth, the terror of st custards

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