Mysterious Planes Over Baltimore Spark Surveillance Suspicions
If you're big into crowd-sourcing:<p>There are super-inexpensive RTL-SDR dongles[1] that can be used to track airplanes such as this.<p>I'm not a lawyer, but I've fooled around with these dongles and a few programs enough to discern that Gov't aircraft absolutely need to broadcast their info on the 1090MHz band.<p>It wouldn't be much of a stretch to have a few people pop these up and see if they could monitor the airplanes that are monitoring the city! :)<p>Just to expand a little bit:<p>You get an SDR, plug it in and use a program like `dump1090` or FlightAware. The repurposed TV Tuner will then listen to data on 1090MHz and decode airplane's Active Dependent Surveillance-Broadcast (ADS-B) messages.<p>The ADS-B messages typically contain flight callsign, location (lat,lon), altitude, heading, and a few other tidbits.<p>There's a really active community around things like this. [2]<p>[1] <a href="http://www.amazon.com/RTL-SDR-DVB-T-Stick-RTL2832U-R820T/dp/B00C37AZXK" rel="nofollow">http://www.amazon.com/RTL-SDR-DVB-T-Stick-RTL2832U-R820T/dp/...</a>
[2] <a href="http://www.rtl-sdr.com" rel="nofollow">http://www.rtl-sdr.com</a>