You are all blithely assuming that the low amplitude
oscillations of charge around some
average that are received when the receiving antenna is pointing
in the region of the
sky containing the spacecraft show a clear frequency over a
period of four hours or
so when the receiver antenna is so positioned and constantly
readjusted to point
to the spacecraft as the earth moves.
This may be a perfectly correct assumption on your part
and Anderson et al.; parts of the Anderson paper and others
describing the method of amplifying and detecting the expected
doppler shifted frequency are hard to decipher though
George Dishman has been helpful in translating some of the
FFT and PLL jargon.
If the reception was perfectly clear then one would see every
(1/2.11.....) times 10^-9 seconds a crossing at zero ( average
value) of the oscillating voltage.
But because of thermal noise and other radiation other
voltages
are added to this expected set of voltages and so to those at the
zero crossings every (1/2.11.....) times 10^-9 seconds
obscuring|
the zero and to other voltages making zero crossings appear which
are not part of the systematic pattern.
Using phase locked loops one could find a first true zero
and then one could take a second or billions of successive
voltage values
and add them to the next second or billion etc for 60 seconds and
the
random obscuring voltages would cancel out.
Apparently they have done so until recently for Pioneer 10 but
I
imagine there had been a steady degradation and I would like
to know from a radio astronomer what form this degradation
takes??
eg How many regularly spaced zeros do you have to miss before
you decide the data is too noisy to establish a specific
frequency?



"Volker Hetzer" wrote in message
...

"Jonathan Silverlight"
schrieb im
Newsbeitrag
...
In message , Volker
Hetzer
writes

"Jonathan Silverlight"

schrieb im Newsbeitrag
...
In message
, greywolf42
writes
Jonathan Silverlight

wrote in message

conjunction.

There are no modelling of forces on the spacecraft in
the paper
-- construct
or otherwise.

Have you actually looked at the paper??

Yes.

They wouldn't be able to see anything without accurate
modelling of the
gravitational and non-gravitational forces on the
spacecraft.

You are incorrect. The paper does not deal with forces
on the
spacecraft at all. Please read it.


Which part of "An important contribution to the frequency
shift is due
to non-gravitational forces acting on the spacecraft" do
you have a
problem reading?
Maybe my english isn'g good enough but the sentence
"However, the uncertainty
in the thermal model overwhelms any plausible application of
the pioneer
anomaly to Cassini." seems to me that they couldn't model
arrurately enough
for the checking of the "pioneer anomaly". Thermal seems to
refer to the
thermal radiation of the isotope batteries.

That's _very_ interesting. Thanks! I assume you're quoting
"Improved
Test of General Relativity with Radio Doppler Data from the
Cassini
Spacecraft" by Anderson et al., as that's the only hit I get
doing a
search for "application of the pioneer anomaly to Cassini".
It's at http://www.arxiv.org/abs/gr-qc/0308010v1, but there's
a note
that "This paper was withdrawn at the recommendation of the
Cassini
Radio Science Team."
Yep. That's the one.

Version 1 is still available, and they quote a radial
acceleration of
-26.7 x 10^-8 cm s^2 and note that "unlike Pioneer, the
result is not
anomalous".
Hm. Sounds like a contradiction to me. First they say that they
don't
have an anomaly and then they say they couldn't check for it.

Lots of Greetings!
Volker