Interferometric radio-frequency emitter location

A generalised correlation technique is developed as the basis for radio-frequency emitter location employing two or more intercept platforms. The technique extends the applicability of the interferometric correlation approach, as exemplified by the use of the ambiguity function in satellite interferer location, to a broader range of emitter location problems. In particular, the proposed approach allows accurate localisation of RF sources in situations where the motion of the intercept platforms would seriously degrade the performance of the more conventional approach. A generalised correlation function is derived which utilises differential time delay and differential phase which are, respectively, related to conventional time difference of arrival, and frequency difference of arrival and higher-order time derivatives. Criteria expressing the significance of the higher-order terms are also derived. Case studies are presented which illustrate the effectiveness of the proposed approach and emphasise important aspects of the theory. It is envisaged that the proposed approach will be highly effective in most civil and military emitter localisation applications