The following quote comes from the Trig web page for their TN72 GPS.

"Wherever ADS-B technology is used it is worth highlighting that most ADS-B In traffic receivers will only display aircraft traffic that generate a non-zero quality indicator, (also referred to as SIL 1). In contrast a zero quality indicator (referred to as SIL 0) ADS-B Out, is ignored and not displayed on a traffic display – rendering an aircraft invisible."


Does anyone have any first hand experience/information on how common it is for those with ADSB out that report a zero "quality" indicator to be ignored? Is every ATC or airliner actively excluding these targets?


Separately, it's interesting to learn that while the TN72 can provide the higher "quality" GPS information, it appears that some (most?) ADSB-Out Mode S transponders don't have the ability report that they are getting "quality" GPS info. In this case, the TN72 (or equivalent) is a moot point and one would be just as visible (or invisible) with GPS from a Flarm or other generic GPS unit.

So, it would be interesting to know just how prevalent it is that non "quality" units are being ignored.