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Comment by computerex | Hacker News Reader

Do you have a reliable source for any of the stuff you are claiming to be true? Because you are not making any sense.

Read up on SEAD tactics, it's pretty interesting. The nature radar propagation and reflection means that a plane will know a radar is active long before the radar can detect the plane. Planes can then fire anti radiation missiles that home in on the radar emissions source. Also, most radars are limited by the horizon. Low level flying can let planes get close without detection.

Now this doesn't mean destroying air defenses is easy. Factor in smaller SAM sites dispersed around th larger ones, as well as enemy air superiority fighter operating in the area and SEAD gets more complicated. SAM sites also sometimes turn their radars off until planes are close and ambush them. But SAM sites alone are not an impervious defense against air power.

Detected with what, AWACS? Do you know how big those radar signatures are?

Detected by Radar Warning Receivers (RWR). These are passive sensors, they're listening to the radar emissions that other planes and Radar stations are emitting. Because the radar needs to send a signal that bounces off the plane and have enough energy for those bounces to travel back to the radar, whereas th RWR only needs to detect the emissions traveling from the radar to the plane the radar will be detected by RWR from much further away. Most modern aircraft carry RWR, not just AWACS.

1. Let's stop re-explaining how radar works as an argument, everyone gets it. For those who don't - radar works like turning on a flashlight, end of story.

2. Non-SEAD RWR is generally limited to "There is light shining on me." Not where it's coming from, let alone providing targeting information.

All modern (1980s and later) RWRs can determine the bearing of emissions. Heck, even the RWR in the Mig-21 (1950s plane) could determine bearing. With bearings known, all you need is two planes to determine location by taking the intersection of the two bearings. Most RWRs can also identify the type of radar, as well as whether it is searching or locked into a target. Planes can also equip targeting pods that have even more advanced passive sensors: https://en.m.wikipedia.org/wiki/AN/ASQ-213

Passive sensors have advanced significantly.

The sensor you linked is limited to SEAD missions in most occasions.

I am going to admit to moving the bar - but at this point you have MIG-31s in the air looking for SEAD and taking down any AWACS.

Planes can then fire anti radiation missiles that home in on the radar emissions source

It’s worse than that (for the defender). Missiles can loiter and wait, if the emitter is switched off, then strike when it switches back on again.

>a plane will know a radar is active long before the radar can detect the plane.

The other bit of information that might be perhaps missing from some (other!) explanations is that this arises entirely because the ground station has to receive a radar reflection _of the original beam_ from the target. Given that power goes as 1/r^2, this means that in practice range drops off sharply for the ground-based station as 1/r^4. Meanwhile, the aircraft can just _detect_ some sort of blip-over-thermal power spectral density coming from somewhere. Given identical amplifier performance (which, with good designs, should be limited by physics) and you end up with the attacking aircraft "winning" from a back-of-the-envelope point of view.

This ignores the fact that it can be traditionally quite easy to confuse radar by "just" transmitting the "right" signals at the right time. There's a good 1960s video that explains a lot of the basic ideas here: https://www.youtube.com/watch?v=pyFqaaqqph0

You might also cite some sources for your claims...

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