Spatial acquisition of satellite transmissions in the presence of ephemeris errors

One component of the Automated Remote Tracking Station (ARTS) Program is the ability to acquire a satellite transmission automatically. Under abnormal conditions, where the ephemeris is not precisely known, it is necessary to ensure that the antenna is positioned on the main beam prior to engaging monopulse tracking to complete the acquisition. The ARTS program uses an automated main beam acquisition procedure that is based on auxiliary-aperture amplitude comparison (AAAC) for initial main beam detection, followed by centroiding for main beam convergence. A method for determining a robust decision boundary for use in AAAC is presented. Compared to other methods, this boundary allows for greater tolerance of errors at a lower cost to the input dynamic range. Several improved alternatives to centroiding for main beam convergence are also presented. These techniques are not restricted to satellites and can be used to acquire the transmission from any transmitter.<>