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Old 30th Apr 2014, 08:45
  #10314 (permalink)  
henra
 
Join Date: May 2010
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Originally Posted by Profit Max
Robin Clark, I think you are misinterpreting the Doppler effect. The numbers show a frequency offset. So when the satellite and the aeroplane are moving towards each other, the frequency is shifted up. If they move away from each other, the frequency is shifted down.
Indeed.
Altitude variation will have negligeable effect compared to direction variation.
What strikes me is the spike around 18:25 in the actual values which is missing in the simulations. Did they not try to re- model and re-fly the actual track based also on the Radar data they have?
To me it seems not, which would have been a mistake IMHO.
Because due to the resulting positional variance this course change will have consequences on the relation of course flown and Doppler reading during the subsequent phases of the flight. By flying the same path/positions in the first stage, the direction of the flight could be more exactly derived in the latter stage by comparing the steepness of the Doppler change. This steepness will correspond to a combination of speed and course. At the same time speed and course are related to each other via the time distance between crossing the arcs.
Due to this double relationship you could theoretically narrow down the possible combinations significantly.
That would have given an important further data point for narrowing the search Location.
Would it be thus worth to do another re-fly of the whole flight path based on all the data they have now and then let the boffins re-calculate based on this?
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