> The F-22 is out of production and there's no practical way to build more.

Lockheed Martin have all the manufacturing equipment in storage and have been trying to sell the Pentagon and others on the idea of restarting the production line to build more F22s with upgraded avionics/electronics taken from the F35. To offset the cost of restarting production they propose allowing Japan to buy them too since Japan has been keen on buying them for a long time.

Actually the tooling is owned and possessed by the USGov, not LM. And restarting the production line isn't as simple as flipping a switch. You'd need all the components made by subcontractors (that are out of business). And you'd also need to find assembly workers familiar with the processes involved in fabricating the airframes etc. Plus the technology is OLD. The avionics are old, 1980/1990 designed systems. So you'd naturally want to upgrade it to the latest standards, which would cost more money and extend the time required to deliver a plane to the AF.

What you're saying about long wave is true for monostatic radar where you're using the angle of the beam to localize the target. In the multistatic case, you don't need to do this, it can be all timing based. This wasn't possible in the past because we didn't have the ability to easily synchronize clocks to high precision and the computers and communication technology to easily fuse the results. We do now though.

That's more of a theoretical possibility than something that can be used operationally today.

It's a bit more than a theoretical possibility. 5G requires cooperative MIMO. If you can do cooperative MIMO, you can build the type of radar I'm describing. I don't have insider knowledge, but this is something that has been openly talked about for over twenty years. I'd be shocked if someone doesn't have at least a working test system.