Flight track log - missed updates shows estimated

FlightAware ADS-B Flight Tracking
1

Hi,

What does the solid white line in this flight path mean?

https://flightaware.com/live/flight/ETD131/history/20191021/0655ZZ/OMAA/KIAD

Is there any documentation explaining all these different scenarios?

Thanks.

2

The white line is an estimated track while the aircraft was out of range of terrestrial ADS-B coverage. If you look at the track log, you will notice a “gap in available data” between approx 1450Z and 1750Z - this is the part of the track that corresponds to the white line.

3

Thank you @obj. What does terrestrial ADS-B coverage mean ? Are those known areas where we always show white solid line ?

4

Terrestrial = land based.
Data received by land based receivers and fed to FA.

In contrast: space-based receivers: Aireon Space-Based ADS-B Flight Tracking - FlightAware

There is a coverage map:
FlightAware ADS-B Coverage Map - FlightAware

And terrestrial coverage is where there will be data.
As normal user you don’t get access to the space-based data, so you are shown an estimation of where the plane was. The white line is not actual data but a best guess.

5

To add to what wiedehopf said, ADS-B is essentially limited to line-of-sight reception, limited by the horizon, so in areas where there are no nearby terrestrial (i.e. Earth-based) receivers that can see the aircraft - notably over the oceans away from the coastline - we don’t receive ADS-B data from the terrestrial network. That’s what the coverage map reflects.

6

Thank you again @obj and @wiedehopf.