I thought you might like to see a couple of screenshots taken from SkyDemon during MLAT testing on Friday using the latest pre-release PilotAware and SkyDemon Software.
The screenshots - taken a couple of seconds apart - show a couple of local ‘ADSB’ equipped aircraft, plus three ‘pure Mode-S’ Aircraft (at bottom-centre and bottom-right of the screen) whose positions were rebroadcast via MLAT from the OGN-R station at East Fortune, some 10 / 20 miles away. The rebroadcast is also supported by overlapping broadcasts from other local stations at Edinburgh West and Balerno.
The screenshots clearly indicate how PilotAware can now differentiate between Rebroadcast MLAT traffic and ‘traditional’ known position (ADSB) traffic by alternately displaying the Aircraft Reg (+ Relative Altitude) and ‘M - for MLAT’ (+ Relative Altitude).
A later flight that day shows further Mode-S/3D and FLARM traffic (Denoted by ‘-G’ + Relative Altitude) received at in excess of 20 miles from the nearest of the 3 Rebroadcast Stations.
Of particular significance is the fact that (as with known-position ADSB traffic) this traffic was received at a range of between 5 and 30 miles, which clearly allows the pilot to monitor approaching aircraft well before the proximity of that traffic would present any danger to their own aircraft. If, of course you DON’T want to see traffic at that range, it’s a simple matter to zoom in your screen to show a smaller area, and of course PAW audio alert ranges are user selectable on the ‘Configure’ Screen.
I have been out again today specifically testing SkyDemon visual position reports and SkyDemon audio position warnings from MLAT aircraft against their visual acquisition and am happy to report that in every case, the aircraft appeared right where the visual and audio prompts told me they would be
. OK, these tests were ‘subjective’ rather than scientific, but I have been testing Mode-S Rebroadcast for over 6-months now and - far from the ‘worst case scenarios’ being mooted on this Forum - I have never
been notified of an aircraft which was found to be at any significant distance from its reported position.
Taken together with the fact that we aren’t looking at ‘tracks on a screen’, but are being prompted to carry out a visual scan for an aircraft approaching from outside visual range, I personally have no concerns whatever with the Rebroadcast system, though that doesn’t of course mean we will rest on our laurels and will continue to refine and improve the accuracy of our reporting as already advised by @leemoore1966