Computer antenna pointing for orbital debris radar

A Kalman filter using rate gyro information from the Space Station Freedom high-gain antenna (HGA) and observed unit pointing vector to target satellite is introduced to compensate for pointing errors due to structural oscillations of the long, flexible boom on which the antenna is mounted. An application to orbital debris radar is discussed. A computer simulation was implemented to demonstrate proof of concept. In the program, the HGA is modelled as a six-foot-diameter parabolic dish which radiates in the Ku-band. The flexible tower has a total length of about ten feet. Gaussian noise on the measurements of the antenna gimbal angles and rate gyros is taken into account. The pointing accuracy goal for this design was chosen to be one-half of the 3-dB beamwidth, or approximately six milliradians. The simulation results demonstrate that this objective can be met.<>