(some of those thousands signals can be dependent on GPS too...)
it is possible to listen to small part of spectrum thru receivers which enthusiasts connected to internet, without buying anything for example -http://kiwisdr.com/public/
but "high performance signals" are not in frequency range of those radios. but it is possible to hear ham radio, aviation, military, maritime, not only voice but weather fax, other digital signals, all sorts of timing signals...
it is possible to listen to small part of spectrum thru receivers which enthusiasts connected to internet, without buying anything for example -http://kiwisdr.com/public/
but "high performance signals" are not in frequency range of those radios. but it is possible to hear ham radio, aviation, military, maritime, not only voice but weather fax, other digital signals, all sorts of timing signals...