A satellite interference location system using differential time and phase measurement techniques

A description is given of the design and development of a system for inferring the position of terrestrial satellite uplink stations using existing domestic satellites with minimal disruption to normal satellite operation. Two methods are presented by which a quantity measured at a terrestrial receiving site is mapped into a curve of possible uplink locations on the Earth´s surface. One method involves measuring differential time delays of a single uplink signal observed through two adjacent spacecraft. Another method uses a short baseline interferometer composed of the two cross-polarized and spatially separated antenna feeds aboard an affected satellite. A unique location is obtained by employing an appropriate combination of the two presented methods. A system for measurement of the required differential delays and phases is described in addition to experimental work performed to demonstrate the feasibility of these location methods