[time-nuts] MH370 Doppler

[Chris Albertson]

The total Doppler in this case is on the order of 100 Hz.   The tiny
frequency shifts of an out of spec OCXO is just to small to measure.
The data says at UTC 18:30 the shift was in the mid range and was
about 175Hz.       Assume the OCXO drifts 10 parts per million.  That
is a lot for an OCXO.  But maybe the effect is only about 50 feet on
the ground.

The OCXO error of even 1E-5 is just not very important as it does not
move the aircrafts ground track enough to matter.

On Tue, Aug 19, 2014 at 6:26 PM, Joe Leikhim <jleikhim at leikhim.com> wrote:
> I raised this on the Duncan Steel website and was pretty much blown off.
>
> "Oh there is a nice stable OCXO aboard" etc.
>
> Well DUHH yes there is an OCXO aboard and if it is good to -20 to +75C, or
> just -20 to +60C and there is a huge fire raging around it for an hour, and
> then perhaps later the plane decompresses at 32,000 feet and ice forms
> inside the aircraft that all has to be a factor to consider.
>
> The ATSB (Australian NTSB) report is mute on this as well.
>
> Plus the Doppler reports are only every hour or so, so there isn't much of a
> trendline. But some interesting excursions.
>
> I was surprised no time-nuts have ventured over to that blog.
>
>
> "David I. Emery" wrote:
>
> "Of course if environment significantly changes the drift performance of
> that particular OCXO it is possible that temperature, or pressure or power
> conditions were so different on the fatal flight that the drift might be
> larger and unknown in character... not sure. It is an error to consider of
> course. Not clear to me how carefully it has been or what possible factors
> have been considered. But surely the folks doing the analysis know about
> these issues."
>
> --
> Joe Leikhim
>
>
> Leikhim and Associates
>
> Communications Consultants
>
> Oviedo, Florida
>
> JLeikhim at Leikhim.com
>
> 407-982-0446
>
> WWW.LEIKHIM.COM
>
>
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-- 

Chris Albertson
Redondo Beach, California