Anyone know of systems that would detect some of the radio signals from police vehicles?
I am not interested in eavesdropping since that can be illegal and tough with encrypted channels.
What I am interested in knowing is if anyone makes a device that finds sources in the 800Mhz range or other "public safety" bands and then lets you detect their direction and distance?
I've also heard that many police vehicles today have an onboard computer to let them access databases. Again, I don't want to eavesdrop but it would be nice to be able to "home in" on such signals so that I can determine their distance and bearing.
I am hoping to supplement radar and laser detectors with equipment that lets me know when police vehicles are close by.