Uzytkownik "Jim Lux" napisal w wiadomosci
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Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?
Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.
As a practical matter, precise measurements of the time of flight to/from
a spacecraft is used to figure out where the spacecraft is and its radial
velocity.
Typical range accuracy is on the order of a few meters, velocities good to
a few cm/s, for something at the orbit of Neptune or Uranus.
Precise doppler measurements are used for radio science experiments, e.g.
to determine the internal structure of a planet or moon by precisely
measuring the orbit of a satellite. A typical performance for such a
measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or 8GHz.
Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm
We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.
Lately the one way is possible with the Mars. But independently for radio
waves and light. Mars has the satellite and radio transmitter.
In next your post is Table 1 and Fig 2. There are electrons density and
temperature. Speed of waves is temperature dependent.
Roemer's method is able to measure the speed of light in different region of
Solar system. Before me Maxwell was interested in this: "Incidentally,
Maxwell once suggested that Roemer's method could be used to test for the
isotropy of light speed, i.e., to test whether the speed of light is the
same in all directions. Roemer's method can be regarded as a means of
measuring the speed of light in the direction from Jupiter to the Earth.
Jupiter has an orbital period of about 12 years, so if we use Roemer's
method to evaluate the speed of light several times over a 12 year period,
we will be evaluating the speed in all possible directions (in the plane of
the ecliptic). "
It is interesting that Roemer has measured 220 000 km/s.
S*