When this story broke last month that the Feds had dispatched an extradition plane to fetch Edward Snowden, I followed it with interest. I have just begun tinkering with plane tracking through their ADS-B transponders.
There are plenty of aircraft who would prefer not to broadcast their position. These include, among others, the rendition/extradition planes used by our government. Rather than use the position-broadcasting ADS-B transmitters, these aircraft use Mode-S transponders which don’t include position.
Usually these planes can only be tracked by radar, however some enterprising folks have figured out the technology needed to triangulate these planes positions, using multiple ground-based receivers. Called multilateration, hobbyists using tools like PlanePlotter can combine their receiver data to plot the position of a mystery plane. This technique has been used by activists to “out” the black ops aircraft which would normally fly below the radar (well, technically above the radar above 45,000 feet). The same technique was used to get the approximate position of Malaysian Airlines Flight 370.
You can read how PlanePlotter uses multilateration here. I find it fascinating and would like figure out how to participate.
On the evening of 24 June 2013, as Snowden arrived in Moscow from Hong Kong intending to fly on to Cuba, an unmarked Gulfstream V business jet – tail number N977GA – took off from a quiet commercial airport 30 miles from Washington DC. Manassas Regional Airport discreetly offers its clients "the personal accommodations and amenities you can’t find at commercial airports"
.Early next morning, N977GA was detected heading east over Scotland at the unusually high altitude of 45,000 feet. It had not filed a flight plan, and was flying above the level at which air traffic control reporting is mandatory."The plane showed up on our system at 5:20 on 25 June," according to our source, a member of an internet aircraft-tracking network run by enthusiasts in the UK. "We knew the reputation of this aircraft and what it had done in the past."
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via CIA rendition jet was waiting in Europe to SNATCH SNOWDEN • The Register.