My take on how to detect and counteract stealth aircrafts

Well, today I'm going to take on a possible solution to detect and counteract the so called stealth or invisible aircraft.
To do so, I will focus on key requirements that can make the system both doable and reliable.
This requirements ate as follow:
- Technical availability: Using already proven technologies in novel combined ways in order to provide a new solution to serious threat.

- Budget friendly: It must be affordable both on acquisition and maintaining so that anyone who wants it could buy it.

- Reliable and attack resistant: Most be able to detect any stealth threat 99.9% of the times, as well as endure a focused attack.

So, based on this 3 premises I came up with the following solution: Microphones and high resolution thermal imaging!!! Yes you read it right!!!

Here's the neat part: You mount high sensitivity microphones coupled with thermal imaging cameras pointed to the sky in a series of masts arranged on a grid pattern distanced from each other 20Km covering the territory you want to protect connected in tandem with the conventional radar system. All this systems will be connected by fiber optics to a central managing system.
An AI system then would compare the real time readings "collected" from its portion of the sky with both the signature recordings from a database of the sound frequency and thermal signature of the different jets (civilian and military, passenger, cargo, bomber or fighter) and the conventional radar readings. By doing so, the system will identify the readings that don't appear in radar as possible stealth or clandestine flight overs. The grid pattern and superposition of this sensors would make it possible to the AI give in real time an identification of the kind of aircraft, its speed, location and heading, so that authorities could respond as they deem appropriate. A very similar approach to the system of detection and tracking of submarines. And, unless they use silencers on their engines, an acoustic sensor calibrated to filter the frequencies of air pressure waves that both the air displacement and the exhaust of jet engines cause, could cover a considerable section of the sky even at high altitudes...

The advantages of such a system are obvious. They could be easily use the communications infrastructure already in place, they are redundant, they use a passive detection system,
and most important, it would be a very efficient and alternative way of monitoring airspace... the technologies already exists... They just need to be used in a new way...

You champs no need to kneel on my keyhole now and mine my fucking guts... just fucking read this and show it to your best minds... they will now what to do with it...
the downside is that you can no longer claim it as yours... oh well... tough luck... you can always pretend. to those of you who still believe in living and working with a straight spine, and don't do everything or anything for an advantage, well , you now have the same advantage that my parasites entourage have...  in this matter.