Imagine I was working in the woods and dropped my cell phone somewhere in a large area where it is now hidden beneath dense vegetation. By calling it I confirm that either it has powered off or its battery is dead. How can I find it?
A consumer metal detector (induction magnetometer) will easily find it if I can get within a few feet of it. But there must be more efficient means of finding electronics in a wide wilderness area given their unique and unnatural characteristics. For example:
They contain dense, refined metals. There is easily more copper, nickel, and perhaps a few other elements in a phone than in an acre of wilderness almost anywhere.
They contain antennas. Even when powered off, the electronic structures are there to receive and transmit signals efficiently in a particular spectrum.
Can radar be used to discriminate either of these characteristics and provide a practical means of scanning a large area to zero in on the device? Are there existing systems that do this?