Ask HN: Ads-B Tracking PD Helicopters in South SF Bay Area

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=~2b093f

I 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?

3 comments

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schoen 5y ago ↗

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.

wiedehopf 5y ago ↗

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.

ModeC MLAT ... is theoretically possible but you can't tell the aircraft identity and implementation is complicated and not planned.