Question for ana1936
ana1936 posted some time ago:
"The red arcs are determined just by working out the accurate distance of the ping source from one single satellite (IOR).
The ping messages are very accurately timestamped using very accurate clocks at both ends. Even though this communication system is not for GPS purposes it uses similarly accurate clocks. So we know that the plane was, say 38000km, from the satellite at 0:11Z.
That gives a circle on the surface of the earth.(The so-called 40 degree circle).
No other satellites could be used as there are only four satellites altogether in space listening for ACARS pings. They do not cover the relevant longitudes: they are below the horizon from most of the Indian Ocean and middle Eurasia.
The fact that that the other satellites (POR and AOR-E) did not hear the 0:11Z ping rules out some chunks of the red circle.
This leaves the two red arcs."
ana1936 - your posts have been first class. Are you satisfied with the gap between the two red arcs and that it appears that POR did not pickup the ping? Perhaps, being near the extreme range limits of POR, it can be acceptable that the ping was not received ??
Last edited by Mach2point7; 17th Mar 2014 at 02:14.
Reason: Improved language