Originally Posted by BOAC
Anyone - have we seen any estimates of a/c radial groundspeed from the BFO data from Inmarsat?
I'm not sure I understand your question. The aircraft radial groundspeed to the satellite is determined from the BTO (Burst Timing Offset). It is equal to the distance between two successive arcs divided by the time difference between those arcs. The north-south component of the aircraft velocity can be calculated from the BFO (Burst Frequency Offset). The accuracy of both calculations is critically dependent on the precision that the true BFO and BTO values are known (*), and that is the reason for the uncertainty about probable trajectories.
(*) EDIT: That applies in particular to the BFO value. The notes on page 2 of the Inmarsat release explain the factors that may affect the accuracy.