Very true, I just want to make sure we aren't taking the "stealth used to be perfect but passive radar makes it mostly useless" claims at face value. Passive ra

Very true, I just want to make sure we aren't taking the "stealth used to be perfect but passive radar makes it mostly useless" claims at face value. Passive radar certainly isn't useless and it does tip the table towards detection. It only tips the table, though. By using ambient RF it is very difficult to track, but very easy to spoof and mess with. How well would it deal with a dozen drones omnidirectionally blasting the star-spangled-banner at high amplitude over FM with a bunch of wacky reverb (and maybe a few leads/lags chosen to look like scattering)? Traditional active radar wouldn't have the slightest problem rejecting interference at that sophistication tier, but most passive radar systems would have a tougher time. As for stealth, > Want to active-cancel the VHF signal? You'll need a transmitter for that. Like antennas in the skin hooked to software radios with resilient analog front ends? To my ears, that sounds like a bet that payed off. > How many can you miniaturize into your fighter A few, probably. That's not enough to do active cancellation at microwave wavelengths, but it might be enough to do active cancellation at VHF. > You have to detect the signal quickly enough and recognize that it's a signal With active radar, that's the game. With VHF passive radar, you characterize the "ambient" radiation, which in this case probably boils down to mapping the FM stations. It's public information, and that is both the greatest strength and the greatest weakness of passive radar.