Performance analysis and simulation of the SPS reference phase control system

The major elements required in the operation of an SPS which employs retrodirectivity as a means of pointing the beam to Earth include the spacetenna, the rectenna, and the pilot signal transmitter. The phase control system is faced with several problems: (1) path delay variations due to imperfect SPS circular orbits; (2) ionospheric effects; (3) initial phase beam forming; (4) beam pointing; (5) beam safing; (6) high power phase noise effects; and (7) interference. The use of SOLARISM, a computer program to select pilot signal parameters and evaluate SPS performance is described.