Ads-B Tracking PD Helicopters in South SF Bay Area

Question

Any ADS-B heads in the SF Bay Area can help me track the answer down.A couple months ago if I heard the ghetto bird flying overhead I could jump on adsbexchange.com and find the details. It was always a tail number ending in PD.Now I can't, for about the last 2 months, see that info anymore. It's clearly PD overhead, but I just see MLAT info now. Like this. https://globe.adsbexchange.com/?icao=~2b093fI know buzzfeed put out that article about tracking military/police flights in June, which drew a lot of attention to this info. Even though it had been available for a while by then.Why did this info only recently get censored? Any change in law or is this just someone finally realizing the info was there and squashing it?

wiedehopf · Accepted Answer

We're not censoring anything.They changed their transponders to either military stuff or ModeC which can't be easily identified.TIS-B are traffic information broadcast by ATC so we're not getting signals directly from the aircraft.

schoen · Answer

There were a few recent HN posts about "ADS-B privacy"https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...I wonder if the change you're seeing is due to adoption of this new mechanism.

Ads-B Tracking PD Helicopters in South SF Bay Area

We're not censoring anything.
They changed their transponders to either military stuff or ModeC which can't be easily identified.
TIS-B are traffic information broadcast by ATC so we're not getting signals directly from the aircraft.

There were a few recent HN posts about "ADS-B privacy"
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
I wonder if the change you're seeing is due to adoption of this new mechanism.