How does the Pro Stick Plus record the time for an ADS-B signal? Is it based on the computer system time, or is it from the aircraft signal?
It is based on an internal clock within the USB dongle. FA back end systems use this information and site location information, and other feeder information to perform MLAT.
Thank you for the quick response. Do you know why the ADSB time we receive from the USB dongle is behind by about 3s? Is this an issue with the dongle itself?
The software decoder counts the samples.
Thus it’s a free running clock based on the SDR oscillator.
It’s zero when the software decoder starts.
But this is the beast timestamp, it’s pretty much not exposed to the user.
So i get the impression you’re talking about something different.
What are you looking at?
We have a software that stores the timestamp that flightaware gives us from the SDR. When comparing it to GPS data, or even FlightRadar24, the timestamp we stored directly from the ADSB signal from the SDR is off by around 3s (delayed).
That’s still not specific enough.
Also you say from the SDR … how do you know it’s from the SDR?
Because probably it’s not.
Second level description: It is Flightaware Magic.