Message posted by kegdr (Member since 02/08/2023) on July 24, 2023 at 9:15:41 PST:
Most aircraft that don't show on flight trackers are still using a transponder and are still in contact with ATC (not due regard, which isn't related to transponder modes), just using a mode that we can't so easily track. When B-2s visit the UK I know for a fact that ATC have been able to monitor their positions. There are encrypted versions of ADS-B for military use, as well as modes 'below' Mode S which, when interrogated by a ground unit, will transmit some information depending on the specific transponder modes in use. Mode C, for example, contains altitude information, while Mode A contains the aircraft's squawk code. To the public it can be difficult, though far from impossible, to track these - the most tricky thing is tracking them *and* also knowing what they are, because without a Mode S hex code there's no accessible identifying information for the airframe. You go back to needing someone nearby with radio comms listening out for squawk and altitude allocations. U-2s are an easy find though as there's not much else reporting an altitude of FL600.
In Reply to: Re: Beginning of the end of ADSB Tracking posted by Jason S on July 20, 2023 at 8:46:49 PST:
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