Originally Posted by
DaveReidUK
That's why, for example, the lat/lon values at 04:13:12 and 04:13:13 are identical, which is impossible unless we're talking about a helicopter or a vertical dive/climb with zero groundspeed.
So, essentially, the only values that can be taken at face value are those that have actually changed compared to the previous row in the table.
And even some of those are suspect - I have yet to see any explanation of the apparent 5g deceleration at 04:13:00 other than the timestamps being out of sync, GPS/NTP notwithstanding.
Strictly speaking, since FR24 only reports lat/lon to 3 digits after the decimal point, 0.001 degrees of latitude is 100 m, and the aircraft is only going ~100 m/s at that point, it's not impossible for two adjacent packets to have the same coordinates.
Presumably, the velocity parameter is airspeed and it's taken from the pitot-static system. Explosive decompression at 04:13:00 could explain the fluctuations both in reported altitude and in airspeed. I don't think that there was a timing issue, since reported lat/lon values progress smoothly.