Geolocation of source interference from a single satellite with multiple antennas

Abstract

Interference of satellite communications is a frequent and ongoing concern for both DoD and civilian enterprises. Geolocation of the interfering source is an essential step in mitigating or eliminating the interference and restoring operation of the communications service. Existing techniques to locate sources of such interference are not applicable to newer satellite communications systems. This thesis offers an innovative method for locating interference that takes advantage of modern multi-antenna satellites. The location of a source of radio frequency interference can be determined by comparing the received signal strength across multiple antennas on the same satellite. The difference between signal strength'as received by the satellite antennas'can be computed and plotted as lines of position on the surface of the Earth. The intersection of two or more lines of position represents the location of the interfering transmitter. An advantage of this method is that it is completely passive and can be done in real time. The size and accuracy of the resultant geolocation area are a function of a number of different factors, including terrestrial latitude of the interfering transmitter, the accuracy of the signal strength measurement, and the geometry of the intersecting lines of position.