Originally Posted by
Gysbreght
... that the BFO value at 22:41 indicates that the airplane is heading almost due east at that time ...
Hi Gysbreght,
I tried to double check your above conclusion but come to disagree.
To my interpretation in your graph the red line (calibration) represents
DeltaFdown + deltaf_sat + deltaf_AFC + deltaf_bias
from equation (2) page 55. The difference between red and blue line then represents the remaining
DeltaFup + deltaf_comp
At 22:41 this difference between red and blue line happens to be almost zero.
In richardC10's nomenclature DeltaFup + deltaf_comp is:
DeltaFup + deltaf_comp = D1aircraft+D2aircraft + D2Satellite
with
D1aircraft+D2aircraft : error remaining after imperfect compensation (miscompensation)
D2Satellite ............ : Doppler component caused by sat's motion towards aircraft position
That means D1aircraft+D2aircraft and D2Satellite are of equal size but different sign at 22:41. For an assumed position of 15S 98E at 22:41 I calculate D2Satellite as 3.9 m/s or ~21Hz.
Then the miscompensation also was ~21Hz which leads me to a guestimate of 320+-100 kts for the southward component of the speed.