Simulation of defence systems

I want to know, what the problems are in simulating targets for defence systems ?
Defence system could be radar, infrared or sonar based.

defence systems works with radas.if u have more intrest see the DRDO web site

thanks. I have to give a presentation, discussing the problems related to simulating targets. IF you have any related documents or links, do post them.

check this link
http://eesof.tm.agilent.com/applicat...rospace-b.html

khouly

lot of Radar books are available in this forum to understand defence systems