FEASIBILITY STUDY AND DESIGN OF AN ANTENNA POINTING SYSTEM WITH AN IN-LOOP, TIME-SHARED DIGITAL COMPUTER.
Abstract:
The report describes the application of time and frequency domain analysis methods to the study and design of a computer controlled pointing system for a 60-foot parabolic dish antenna to be used in satellite tracking. The emphasis is on the time domain methods including state variable matrix techniques and digital simulation. The validity of the analysis methods is shown by their application to well known examples. The effect of delay in the feedback path on stability is studied. A compensation scheme to combat the undesirable effects of feedback delay is discussed and its limitations noted. The feasibility of including a real time digital computer within the feedback loop as a data source and for digital compensation was studied. The effect on system stability and performance of a random processing delay was examined as the computer was to be available only on a time-shared basis with other tasks. The computer interface and antenna control equipment designed for the system is described in moderate detail. The computer program used for the antenna control and digital compensation is discussed, as well as the improvements in performance made possible by its use. Author