Cross-spectral TDOA and FDOA estimation

We present methods for accurately estimating and tracking instantaneous frequency and relative time delay of narrowband signal components. These methods are applied to the problem of estimating the location of an emitter from the signal(s) received by one or more receivers. Both instantaneous frequency estimation and time delay estimation are based on previously reported cross-spectral methods that have been applied successfully to a variety of signal processing problems. Accurate geolocation is accomplished by matching the Doppler characteristics of the received signal to Doppler characteristics estimated from the known emitter motion and possible emitter locations.