George Dishman suggested to me that Doppler signals sent to
a spacecraft and relayed back to earth would provide a good
test of the instantaneous speed of light hypothesis.
That hypothesis states that the r/c delay in light does not
extrapolate
beyond c but at great distances does not increase beyond a
maximal value. Thus a
light source, 30 time 10^8 meters away, like a source 3 times
10^8
meters away still produces an effect in a second (due to
instantaneous forces that produce a cumulative effect rising
above threshold after such a one second at most delay)
The problem with this proposed test is that Doppler data
that is inconsistent with the speed of light assumptions is
partially or entirely filtered out by NASA.
According to Morabito-Asmar(see Google) paper "The
closed-loop NASA tracking system produces Doppler counts,
Doppler
"pseudoresiduals"( residual based on predicted frequencies used
to tune the receivers),signal strengths(AGCs) and Doppler
reference frequencies either in the form of a constant
frequency or uplink ramps." All this is output on a so called
ATDF tape ,
so frequencies that are too far from the predicted shifted
frequency may be filtered out.
( I am assuming that in this process the carrier frequency is
modulated
so that when a resonant increase of a specific incoming frequency
is produced
it is not Johnson noise or whatever but the code modulated
carrier from the
spacecraft. I am also assuming that tuning around the predicted
shift will occur
so that even if the incoming frequency is not too far from the
predicted frequency it can still be obtained)
Craig Marquardt has further filtered some of these files to
exclude the daily modulations due to the earth's spin, plus or
minus.5km/sec(plus or minus10kHz he claims although I dont
think this takes into account the enormous changes in the
projection
angle between the velocity of the earth and the line to the
spacecraft)
The result is another "data" file attempting to be consistent
with the
speed of light delay . The assumptions of the speed of light
delay are so built
into all of the data coming from NASA that it may be impossible
to
actually test the hypothesis that light is nearly instantaneous.
But lets see. I am told that at 7:38 Mar 7 1988,
rx=2.291710886.9109Hz.

From the telnet ephemeris I find that Pioneer 10 had the
following heliocentric,xyz, coordinates in AU units:
2447227.817361111, A.D. 1988-Mar-07 07:37:00.0000,
1.436437796483437E+01, 4.078001848489932E+01,
2.333352522486281E+00,
2447227.818055556, A.D. 1988-Mar-07 07:38:00.0000,
1.436438157235370E+01, 4.078003529995198E+01,
2.333352811320062E+00,
2447227.818750000, A.D. 1988-Mar-07 07:39:00.0000,
1.436438517997504E+01, 4.078005211560639E+01,
2.333353099907363E+00,
and that the Sun at the same time had :
2447227.817361111, A.D. 1988-Mar-07 07:37:00.0000,
9.674871050446867E-01, -2.212064445087720E-01,
3.105791038669308E-05,
2447227.818055556, A.D. 1988-Mar-07 07:38:00.0000,
9.674901060953275E-01, -2.211948077051214E-01,
3.108019085814273E-05,
2447227.818750000, A.D. 1988-Mar-07 07:39:00.0000,
9.674931072480047E-01, -2.211831702995969E-01,
3.110222484770500E-05,
and so Canberra in solar coordinates would have an x coordinate
which is the negative of the sun's x coordinate here etc.
From this data one gets the craft-site difference vector at
7:38 that represents the craft-site line "d" and the two time
difference vectors (7:38 and 7:37 etc) divided by 60 seconds
gives the speed
of the site,'vs', and the speed of the craft,'vc'.
The dot products of each velocity and the line "d" divided by
the sum of squares of coordinates of "d" gives the projections
of
these velocities on the line, "d" and the difference in these
projected
velocities gives the craft site relative velocity v which plugged
into the
formula above gives the predicted Doppler.
If the predicted Doppler here is close to the observed rx then
the instantaneous hypothesis is indicated.
The problem is to obtain from NASA the correct tx values??????