LOOK-ANGLE-PREDICTION TECHNIQUE FOR ARTIFICIAL EARTH SATELLITES.
NAVAL RESEARCH LAB WASHINGTON D C
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This report is concerned with the investigation of a method for obtaining look-angle predictions for artificial earth satellites relative to a given point on the earth. The input to the problem consists of the most-recently -determined elliptical orbital elements of the satellite, the spherical coordinates of a station on the earth, and a desired time of search. The results to be obtained for the satellite trajectory are azimuth, elevation, range, range rate i.e., velocity, and the doppler frequency shift as a function of time. The problem has been programmed for use on digital electronic computers in both NELIAC and FORTRAN compiler languages and is available for use at both NRL and the David Taylor Model Basin in the Washington, D. C., area. As part of the checking out procedure, a comparison of the results was made with data obtained at the Radio Research Establishment RRE in Malvern, England. It was concluded that the major portion of those discrepancies that exist between the NRL and the RRE data is due to differences in the models used. Examples of both NELIAC and FORTRAN input, an example of the FORTRAN output, and the FORTRAN source program for this problem are included in the appendices. Author
- Computer Programming and Software
- Computer Hardware
- Spacecraft Trajectories and Reentry