On 11/17/17 5:16 PM, Hal Murray wrote:
[email protected] said:
Ok, 1 Hz at 437.5 MHZ is roughly 2 ppb. That is pretty much “slam dunk�
accuracy with a GPSDO. Much easier to obtain and set up in a school
environment. The key will be orbit estimation for the +/- doppler part of
it. Orbit estimation is not quite a slam dunk sort of thing. The GPSDO
would also give accurate location. Even with good orbit data, the solution
still requires a good location estimate.
What is the orbital period? It would be fun to plot the Doppler over time
and see if you can get something that looks like a big chunk of an orbit.
Ugh. What is the Doppler due to the Earth's rotation?
not huge.. Earth is 40,000 km circumference (thank you Napoleon and the
Cassinis), so at the equator the velocity is on the order of 500 m/s
Doppler is about 600 Hz from earth rotation.
1ppm at mid latitudes
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