a radar like Fan Song for the S-75 Dvina could perform a false launch to the enemy which missile guidance signals were transmitted without a missile actually being launched. This could distract enemy pilots, or even occasionally cause them to drop ordinance prematurely to lighten their aircraft enough to dodge the nonexistent missile
but i got a question , for what range could this method deployed ? i know the Fan Song is close to 150 km could it be done at 100 km ?
No, the Fan Song radar cannot do a 'false launch'... The Fan Song radar is there to provide target positioning data to a computer, as well as missile positioning data. The missiles of an SA-2/S-75 Svina are radio guided, using the target and missile positioning data. From what I have seen, there is no reliable way to cause an SA-2/S-75 to spoof a missile launch.
In order for an actual, live warshot to take effect, an SA-2/S-75 would have at a minimum two radar systems hot, a Spoon Rest for initial detection/acquisition and then a Fan Song (which uses two transmitters/antennae on different frequencies at the same time) for positioning. Then there is the actual guidance information the missiles themselves receive via radio-link. All of these transmitters would need to be hot for an SA-2/S-75 system to even look like it was actually firing.
Now depending on who one's opponent is, and how sophisticated their EW and ELINT capabilities are, they may be able to tell which of the emitters are active, and which ones are off and/or transmitting electronic garbage. Given the age of the SA-2/S-75 system, I would not have much faith in it's effectiveness against an aware and reasonably modern opponent.
-Cheers
