0

Two people provided answers to my previous questions:

And they referred me to Appendix G. "Explanatory Notes on BTO and BFO Analysis".

Now I have questions about Appendix G.

  1. The report (Appendix G) says that the Doppler shift from the satellite (down-link) to GES depends on the satellite movement with respect to GES, since the satellite is not exactly stationary. But in Table 6. the Down-link Doppler frequency varies, from the satellite to GES depending on the aircraft Latitude. Why should the Aircraft Latitude affect the DeltaFdown Doppler frequency shift?

  2. And another question is about the Down-link doppler-shifts, from the Satellite to GES, given in Table 5. The listed Doppler-shift in frequency is -75.1 Hz for UTC time 17:07. However, I can only derive this frequency using the satellite velocity for UTC time 16:55:00? The calculated frequency differs slightly from the one in the report.

Community
  • 1
John Mauch
  • 135
  • 3
  • 4
    While I share your interest in this subject, I worry these questions are getting to the point where they don't have a lot to do with normal aviation. More attention to spelling MH370 etc correctly, providing links to info you mention and formatting would probably go down well with the audience here. Just my 0.02 worth. I'll fix that for you on this question. – RedGrittyBrick Jul 28 '14 at 21:04
  • Your reply does not answer the question I asked. You include the aircraft velocity and heading as viewed from the satellite's location as a possible explaination. But the DeltaFdown is suppose to only apply to the satellite movement wiith respect to GES. The Aircraft velocity should not affect the the DeltaFdown value. The same goes for the Aircraft Latitude. I now understand that Mr. Duncan Steel asked the same question about the aircraft Latitude several days ago. Getting answers as to how the Log- Data was derived may help in locating Flt370. Reasonable questions should be encouraged. – John Mauch Jul 29 '14 at 23:39
  • For 16:55 UTC, I calculate a doppler frequency of -74.5 Hz for DelFdown. For 17:05 UTC, I calculate a Doppler frequency of -71.2 Hz for DelFdown. These calculations are based upon the relative movement of the satellite with respect to GES. If there are other variables that contribute to DelFdown then the report should state so. – John Mauch Jul 30 '14 at 01:55
  • Being reasonable is a necessary but insufficient condition for questions here. Questions should also be on-topic and it appears that many people feel this question does not meet that condition. 2) It is better that comments on answers are attached to the answer not to the question. I'd delete my answer but it contains some links and info that may be useful to future readers.
    • – RedGrittyBrick Jul 30 '14 at 09:34