On Saturday, September 24, 2016 at 12:54:26 PM UTC-7, Paul Agnew wrote:
What about the time delay between ground and geostationary satellites? I once helped get an initial STC to put a Satphone in a Lockheed JetStar and I can tell you there is a noticeable delay when you are bouncing signals from low altitude to space and back. Not a huge delay, mind you, but enough to make carrying a simple conversation a little awkward. When we are expecting near-instantaneous position communications between aircraft and satellites, could the delay be substantial enough to skew the warnings?

I see the use of the satellite based collection of ADS-B location packets for high resolution tracking of sailplanes... not as a collision advisory/avoidance system. The time delay round trip to satellites might be an issue there... but not high resolution real-time tracking. One second updates could produce some fairly realistic real-time viewing of gliding contest and activities. I'm not as interested in the intended use for a global Air Traffic Control services ADS-B based system.

BTW, There still would be use for the Delorme Inreach in sailplanes. It's a good emergency services unit that can be attached to a parachute and provide text message/email services from anywhere on the ground or in the air. Although, there wouldn't be a need to the 1 or 2 minute tracking intervals.... 5-10 minutes would be sufficient... if the ADS-B tracking from the glider were logged somewhere for use in emergency location services.

Walt Rogers WX