Jim Lux wrote:
Szczepan Bialek wrote:

But the Mars is the best. Are available data for the Mars?
I don't know why Mars would be the best..

Probably is possible to measure the optic signal from the Mars
satellite. If yes, we have the direct comparison light - radio waves.

I don't think that there is any way to "see" a satellite at Mars.
Perhaps if one did some sort of Moon/mars occultation?

Radio transmitter can be installed only on the Mars.

There are precision transmitters suitable for this kind of measurement
at many places in the Solar System.
You're going to be on your own to find the relevant data files. Try
"radio science" as a search term.


For me will be enough your steatment if speed of light and radio waves
were measured in different regions of the Solar System.
Katz: http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF
wrote that the electron temperatures are from 10^4 to 10^6. Look at
Fig 2. Place the Mars instead a spacecraft. Between (a) and (c) should
be some differences.


Are you asking if the calculations in Katz's paper for the two paths
have been experimentally verified? I don't know..
Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

You wrote: " NASA knows the results. Are they published? Of course,
they're published. Widely."

What the conclusion are?
I do not need the quantitative data.

I'll assert that propagation through interplanetary space is moderately
well understood and matches all modern models of electromagnetic behavior.