PPRuNe Forums - View Single Post - 737-500 missing in Indonesia

9th Jan 2021, 21:16

#61 (permalink)

DaveReidUK

Join Date: Jan 2008

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Quote:

Originally Posted by 2dPilot

Speed and Altitude from FR24 granular data

Thanks for that. It illustrates my earlier comment:

Quote:

Originally Posted by DaveReidUK

Watch out for dodgy timestamps and latency issues.

The momentary climbs during the descent from FL110 and the equally abrupt variations in groundspeed are artifacts as a result of timing issues: ADS-B data isn't timestamped at source, so FR24's timestamps simply record when it arrived at their servers from the various enthusiast feeds regardless of latency.

So the altitude and speed point values on the charts (and also on my earlier chart) are correct, but not all shown at the correct point in time.

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