Originally Posted by
Airbubba
Looks like the FR24 data is from ADS-B (not MLAT) and the location should be from GPS inputs.
The aircraft didn't have GPS when it flew for CityJet, and I'd be surprised if it had been retrofitted, so the ADS-B position reports will be from an inertial source.
That's supported by the fact that the coordinates sent as it turned onto the runway at Viru Viru were offset by approximately 1 nm SSE, so it's likely that at least that much error will apply to the subsequent ADS-B track.