Orbits for calibrators.
Found some MATLAB code on the web that does crude orbit determination. Revised it to also compute zenith angle to satellite from Pachon.
Options: Circular or elliptical versions
Special inclinations:
63.4 degrees has zero precession, as seen from Earth, apogee stays locked over single place on the Earth. So precession rate matches 24 hours.
zero degrees should also have zero precession, esp if circular orbit.
sun-synch: nearly polar for LEO/HEO altitudes.
-30: goes overhead, but only for limited amount of night time due to precession
Precession rate is
omega_p=(-3/2) R_e^2 (a(1-e^2))^-2 J_2 Omega cos (inclination)