Graphics Display of Satellite Rise and Set Conditions

Compute and display graphics information about observer-to-satellite visibility conditions.

This submission describes a MATLAB script named griseset which can be used to graphically display rise and set conditions of an Earth satellite relative to an Earth observer or ground site. The software numerically propagates a J2-perturbed satellite’s orbit for a user specified time duration and step size while collecting rise-set information whenever the elevation angle of the Earth satellite is above a user-defined minimum elevation angle. This MATLAB script calculates the topocentric coordinates (azimuth, elevation and slant range) and their rates with respect to an observer or ground site on an oblate Earth. In this script the topocentric elevation angle is corrected for atmospheric refraction.

After the orbit propagation is complete the user can elect to graphically display one or more of the following items:

• topocentric azimuth
• topocentric elevation
• topocentric slant range
• topocentric azimuth rate
• topocentric elevation rate
• topocentric range rate

This script will also create a simple text file of the rise-set conditions along with a tiff disk file of the graphics.