See:
http://cryptome.org/faa021307.htm
http://www.tc.gc.ca/eng/civilaviation/standards/general-reca...
See:
http://cryptome.org/faa021307.htm
http://www.tc.gc.ca/eng/civilaviation/standards/general-reca...
As this happens there will be some who will take it as a challenge to destroy, capture, and most of all, to take over these drone. That does not entail injuring or harming an officer or a human so those who would never try to mess with a real helicopter or police cruiser might not have a problem messing with flying remote robots.
I wonder if there are any projects that are starting the process from the other side : take a mosquito and bio-engineer it somehow to use as a micro surveillance platform. I wouldn't be surprised if DoD already has such projects underway.
As the size gets smaller, FAA radars won't be able to detect these anymore. They might have to scan the control frequencies perhaps and triangulate to the base station.
As for radar signature, the smaller drones are already barely bigger than a large bird, so I guess they aren't spotted by radars, or at least not recognized as UAVs.
It's like ham radio in the sense that you have very limited and specific rights to use a shared medium so long as you don't interfere with the professional users.
You can do drones in the US, but you have to have line of sight to it at all times, and you have to be able to take control of it at any time.