On Jun 4, 11:24 am, Thomas Borchert
wrote:
Andrew,

Do they work when there is no radar
facility nearby, or you are below the radar altitude?

Your targets must be hit by radar (or an active TCAS from an airliner),
not yourself. If that doesn't happen, the units don't work. How much
traffic will there be in such areas?


Since mid-air collisions occur near traffic patterns at low altitudes
this is where I would want the system to be most responsive. It seems
as if the opposite is true. Identifiying airplanes at cruise altitudes
might make someone feel better, but they are rarely a hazard. It would
be nice if there were a passive system that does not rely on a
transponder, like a laser radar.