Black line is the RPC boresight.
Red line is the CW energy emitted towards the target.
Blue line is the area interrogated by the IFF. (Where the IFF request is sent.)
The target can be pretty far from the drone, while the crew still receives "Im your target".
To be honest, it's pretty hard to believe that they used solely the IFF to identify their target... There is a lot of civilian airways in that area, and the one flown by Tu-154 is actually not the closest one. The restricted airspace around the Feodosian range is small enough, not nearly adequate for S-200. They should have been double, triple checked what they firing at. This is either an extreme recklessness or I don't know what...
By the way, there is another Russian article on the subject:
http://nvo.ng.ru/wars/2001-10-12/3_flight.html
