Re:
What in the world does the APG-77 have to do with what I said about SAM site defense? If you are saying that SAM sites can use the same techniques as the 77, then you need to show some info about them being AESA radars with LPI because if they are not, they are putting out massive, single freq, radar pulses that can be picked up from many more miles away than the 77 will be picked up by the SAM site.
Actually the difference is not that great. An example would be the giraffe radar which employs agile narrow beams for track.
SAM systems need search radars to search for targets which means wide band high power. A search radar which only emit narrow beams aren't going to find or cover much in a 3D environment. Same thing with a fighter aesa radar. Just simple narrow beams isn't going to find much in a 3D environment so there's still going to be a lot of emission on sweeps. A fighter can rely on AEW so it minimises emission. So can a SAM for early warning before using the tracking radar for an engagement which again minimises emission. An example would be aegis. The key is that in all cases, a big emitter is still required.
RWRs are sensitive enough to pick signals even when the beams aren't directed directly at them. Its also easier to ID a target on a 2D pic ie ground as compared to a 3D volume ie air.
One difference not highlighted is that a fighter is moving. Hence it is difficult to compare a beam at a certain frequency in one location to another beam in a different frequency at a different location (eg travelling at ~200m/s or more which can be in several direction). Whereas in the case of a ground emitter, its still the same location (or approx the same location even with mobile transmitters) emitting albeit at differing frequencies. The slower, the easier to ID location. Not exactly rocket science to determine location and ID type.
That's why the F-117 could be downed as the location could be identified due to similar flight path. In that case, they could maintain radar lock on a moving stealth target at close range and minimise RWR detection. Once stealth target is in distance, its a different story.
That's why long range SAMs like PMU/SA-10 are likely to be as ineffective against stealth targets as SA-2s although the engagement range is further.
The bistatic issue needs to be clarified. If there is no emitter, no matter how many receivers there are, there won't be any long range targeting going on. Hence once an emitter is gone, effectively, any radar guided SAM is a white elephant without targeting info.
Again that puts into question how useful passive receivers like VERA can be. It might be useful as a early warning device ie something is out there but not for other. As to detection of passive receivers, its just a function of visually spotting an antenna sticking upwards.
