Recently Dan, a reader of RTL-SDR.com wrote in to let us know about a new web project he’s started called adsbexchange.com. ADSBexchange is similar to services like FlightRadar24.com and FlightAware.com, but with one key difference. ADSBExchange explicitly states that they do not and will not filter ADS-B traffic for security reasons. Other similar services all filter FAA BARR (Block Aircraft Registration Request), military and other potentially sensitive ADS-B data. However, Dan argues that filtering the data is simply unneeded security theatre as anyone can build their own unfiltered receiver for very cheap. He writes:
I recently started a website that collects SDR ADS-B and MLAT data (typically from dump1090) worldwide, and displays it unfiltered – http://www.adsbexchange.com . This means that military, “blocked” and other “restricted” traffic is available to see, which is unique as far as I can tell. We’ve recently tracked a U2 over the UK above 60,000 ft., Air Force One, and various diplomatic aircraft. Additionally, there is a database of all previous aircraft “sightings” searchable on various parameters.
All of my research indicates this is legal, but perhaps “frowned upon” by local authorities. The major flight tracking sites seem to not want to make any waves and voluntarily strip this data from their public feeds, even though they are typically fed “unfiltered” data from their volunteer participants.
The service is currently looking for RTL-SDR users who feed ADS-B data to join their feeding program so that they can expand their service coverage.
Source: RTL SDR