• TDRSS AVAILABILITY FROM THE LUNAR SURFACE

      May, Anna Marie; Center for Space Telemetering and Telecommunication Systems (International Foundation for Telemetering, 1992-10)
      The aim of the present research is to develop a computationally efficient numerical model to analyze geostationary satellite availability from the lunar surface. This simulation includes a menu-oriented interface which facilitates user interaction and incorporates an animated visual display. The animated graphics display depicts the satellite constellation as the simulation progresses and aids in proper evaluation of the model. This simulation is general in configuration and allows for arbitrary input parameters for positioning satellites, specifying the rate of program execution, and specifying the sampling rate. A method of determining when the moon is visible to a geostationary satellite is presented. The effects of varying the sampling rate on the correct determination of the time window in which lunar-geostationary satellite visibility occurs is studied. Large time intervals yield misleading data while small time intervals slow the execution of the simulation. The optimum time interval which yields reliable data was shown to be thirty minutes.