On Nov 2, 1:39*pm, Greg Arnold wrote:
On 11/2/2010 1:28 PM, Darryl Ramm wrote:



You are asking a different question than I was talking about. flarm-
flarm collision avoidance radio links uses GPS altitude and does not
involve pressure. I did not say th PowerFLARM does not use pressure
information elsewhere.

So PowerFLARM uses GPS altitude to avoid collisions, but also broadcasts
pressure altitude, and this is what shows up on the SeeYou screen next
to other gliders?

I was saying PowerFLARM is a PCAS *receiver* it just needs to know the
pressure altitude for that to work - it does not transmit anything.
Same for ADS-B since it is only a receiver.

Flarm and PowerFLARM have to be 100% compatible and Flarm does not use
pressure altitude in its collision avoidance protocol. And I want to
qualify that as far as I know PowerFLARM does not transmit pressure
altitude, but it might, I dont know. And if anybody ever wanted to use
that it might break things so I'm not sure it would ever be a good
idea. See my other post in this thread on how SeeYou Mobile does what
it does which I think will address these concerns.

Darryl

Darryl