I see a number of reports on the MILScanners forum of people plotting the whereabouts of certain US Mil movements over the UK. They say they are using MLAT. Is tthis a feature of a combination of the SBS-1 box and PlanePlotter using a form of triangulation?
ASsume not a feature enabled on RDB? Will it be in the next verson? If not could I sign up with PlanePlotter and get a view of of this without the SBS-1?
MLat (i.e. Multilateration) is a system that can be implemented by taking advantage of a serendipitous feature of the SBS-1 whereby very accurate TDOA (time difference) data can be derived for any Mode S aircraft (with or without ADS-B) that's being picked up simultaneously by 3 or more receivers. Clearly in the case of non-ADS-B aircraft such as bizjets, spamcans and military, this enables the user to track aircraft that coudn't previously be located.
Whether that constitutes a hack or not is a moot point - it's not a patch as such, but works by substituting the FTD USB driver with a replacement that allows access to the USB data stream. The resulting TDOA data is then processed by the PlanePlotter server. As for the legality, the PlanePlotter folks seem to be taking a responsible attitude by a) monitoring who's using the facility and b) making it possible only to get one-off position fixes in near-real-time, but not possible to do continuous real-time tracking.
N.B. the above applies only to SBS-1, AFAIK although there exists a comparable USB driver replacement for RadarBox that gives access to the USB data stream, the latter doesn't contain any timing data that can be used for MLat.
HTH
Dave