In a previous article, "Gene Whitt" said:
electronically to remove all the slow moving targets. Initially it was
possible for an aircraft flying an arc around the antenna at a specific
distance to disappear from the scope. Don't know if problem has been
solved. Anyone know?

I would think that the speed gate would only apply to primary targets, not
transponders, don't you think? If it weren't, it seems that it would be a
mere matter of programming to fix it.

I'm told that fighter planes use the same technique to evade enemy radar
guided missiles, flying an arc around the in-coming missile (although they
use terminology like "putting your z-pole on the target" or something). I
believe fancier radars can apply the speed gate to your speed even if it's
parallel to the antenna, even if it's primary only, but I don't believe
either ATC radar (which is, after all, designed to track cooperative
targets) or older missiles like Sparrow have that capability. I wouldn't
be surprised if AMRAAM and other newer missiles do.

--
Paul Tomblin http://xcski.com/blogs/pt/
I am not a vegetarian because I love animals; I am a vegetarian
because I hate plants. -- A. Whitney Brown