Re: Question For Craig Markwardt re Pioneer 10 Data

"ralph sansbury" <[EMAIL PROTECTED]> writes:

> George,
>     I think I have a pretty good idea by now of the techniques
> used and their reliability  in detecting the actual
> doppler changes in radiation from Pioneer 10.

>From your continued mis-descriptions, I unfortunately doubt you have a
pretty good idea of the techniques.

>    I am curious about the Watola paper that Craig Markwardt
> refers to and
> the summary statement there that the signal is 100 times stronger
> than the noise.Have you read this or do you know what is meant
> here?

I thought it was pretty clear.  At the time of that measurement
(1991), the carrier was about 100 times (20 dB) stronger than the
noise level, perhaps 15 dB if one is conservative.  The power spectrum
presented in Fig 3 of that paper is based on an FFT of the I.F. data.
The carrier peak is clearly detected above the noise floor.  By
eyeball I read off the difference between the two.




>    This is really the important consideration finally. I am
> supposing that either the  difference between the observed
>  sequence of voltages and the fitted sine curve of specific
> frequency
> phase and rms amplitude or succession of these or the difference
> between a sequence of fitted 1s and 0s and observed 1s and 0s etc
> is
> the basis for this estimated error.

You are supposing incorrectly.  The Pioneer analysis is completely
independent of the telemetry (1s or 0s) which is modulated onto the
carrier.

Once the phase locked loop locks onto the signal, specialized cycle
counting equipment is used to count carrier cycles, and accumulated
cycle counts (sampled at regular intervals) is the Pioneer 10
observable.  The numerical derivative of the cycle count can be used
to estimate the frequency, which in turn can be compared to a model of
the same, based on physics.

CM

References
Watola, D. A. 1992, TDA Progress Report 42-111