Geolocation of multiple emitters in the presence of clutter
T. Sathyan, Thiagalingam T. Kirubarajan, Abhijit Sinha · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
In geolocating by time difference of arrival (TDOA), an array of sensors at known locations receive the signal from an emitter whose location is to be estimated. Signals received at two sensors are used to obtain the TDOA measurement. A number of algorithms are available to solve the set of nonlinear TDOA equations whose solution is the emitter location. An implicit assumption in these algorithms is that all the measurements obtained are from a single emitter. In practice, however, one has to deal with measurement origin uncertainty, which is a result of either multiple emitters being present in the region of interest, or clutter returns. In this paper, a method to determine the location of multiple emitters in a cluttered environment is presented. Several unmanned aerial vehicles (UAVs) are assumed as receivers of the electromagnetic emission from the emitter. Emissions received by different UAVs are used to obtain the TDOAs. Using a constrained optimization procedure, measurement-to-emitter associations are determined. Then, the resulting nonlinear equations are solved to find the emitter locations. An Interacting Multiple Model (IMM) estimator is used to track the located sources and to obtain their motion parameters.