Steve, good idea for a first approximation. If under the belly and behind is really a worry that you'd go to some lengths, you could do what the radar boys do - put the glider on a pedestal. I still remember the F-18 I saw on a post 50 feet above the ground...

-John

On Monday, June 8, 2015 at 1:33:40 PM UTC-4, Steve Koerner wrote:
Yes, under the belly is important. This is not really an important consideration for testing however. The reason is that it would be essentially impossible to create an installation that would so strongly attenuate in the under the belly direction compared to the zero azimuth directions such that acceptable range is found at zero azimuth and yet is not sufficient for good anti-collision operation in the very very close range that matter for under the belly, etc.