Recall your basic radio frequency and you will find (by looking at the FCC data base) that, lo and behold, drone radio control frequencies are listed. Understand that the hobby ones are on common public frequencies. The police and para-military ones are on frequencies which are on channels authorized for the police, public safety, and so forth. 1) find the frequencies and plug them into your hand held scanner (preferably with direction antenna); 2) listen for either tones or digital bursts when the drones are in your vicinity; 3) identify those tones or bursts as related to movement of the drone if you want to, but with digital signals it will be difficult without a spectrum analyzer. Next once you have the frequencies (a task of maybe 10 minutes) you can build a burst type transmitter using common hobby parts and usually modified hand-held frequency agile hobby radios such as those made by PuxXing, the radio folks. And, zap away.
Cf. http://www.puxingradio.com/
