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Old 9th Jun 2014, 06:46
  #10990 (permalink)  
BOAC
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Originally Posted by shadoko
but you have a minimum speed (flight direction exactly away from the satellite) and a maximum angle between the direction of flight and the line of sight of the satellite given by the maximum speed of the a/c.
- my point. What prevents detemination of the first from the measured Doppler shift? Obviously if the following is correct, this does......

Originally Posted by Gysbreght
the a/c system assumes the satellite to be at its nominal position and that error results in the BFO.
- if I read you correctly, you are saying that any Doppler shift is PURELY due to satellite motion away from geo-stationary and not aircraft speed? I had understood from all the previous stuff about BFO that it was affected by aircraft ground speed. Now I am told that a/c speed is removed from the equation? Would this not result in a reversal of BFO sign as the satellite 'turned' on its path? Is this apparent in the published BFO data? Can you highlight it?
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