Shadow Conditions of Earth Satellites in Circular Orbits

[cdeaglejr]

This HP Prime computer programs determines beta angle and eclipse characteristics for Earth satellites in circular orbits.

The software will prompt you for the initial calendar date, the satellite's altitude in kilometers, the initial right ascension of the ascending node in degrees and the orbital inclination of the satellite in degrees. It will also ask you for the total simulation time in days, and the time step to use in minutes. The software will also print shadow statistics consisting of the minimum and maximum values of shadow duration and beta angle, and the average shadow duration. For good statistics, the simulation duration should be long enough such that all relative geometries between the satellite and Sun are simulated.

For more realistic shadow predictions, the radius of the Earth is increased by 2% to account for the effect of the atmosphere on the size of the shadow.