I'm late to the FLARM party and my observations were based on only one flight. But what I recall seeing was *in a thermal*, a new target would show up as the only other glider in the nearby sky joined. Then, a circle or two later, there would be two images (I believe they were identical in shape--circles--but I can't swear to it), the second one a much lighter color gray (the "ghost" image I referred to) was usually near but not exactly overlaid on the darker symbol (although I guess I wouldn't have been able to see if they were precisely on top of one another). The light gray symbol quickly faded away in a few seconds. The dark symbol behaved normally.

This happened repeatedly. Given the nearly empty sky that day and the number of times this occurred, the FLARM screen was obviously showing the same glider in two different positions and in two different colors. Was it a case of trying to refresh the screen and displaying where the glider was now and where it had been a few seconds earlier? Or was this cause by some sort of reflected signal? I have a canopy wire deflector cage in the cockpit and the range pattern I saw shows a large narrow loop of enhanced sensitivity way out to the left that caused me to wonder if part of my canopy wire deflector was acting as a parasitic antenna. Or was the fact that my flying buddy was transponder and FLARM equipped causing my FLARM to read him as two targets?

I just wanted to know if this was normal. My buddy hadn't seen anything like this on his display, but he didn't have a portable unit. This was a trial flight with few people flying so I gave the screen more attention than I otherwise plan to in the future. FWIW, I didn't see the same phenomenon for the fast-moving targets up high.

Chip Bearden
ASW 24 "JB"
U.S.A.