TARGET LOCALIZATION AND TRACKING FROM DOPPLER-SHIFT MEASUREMENTS

It is possible to localize a moving source which is nonma-neuvering and radiates a constant frequency tone from measurements of the Doppler-shifted frequency at several sensors. Due to the nonlinear nature of the problem, it is necessary to find the solution by grid searches. However, if measurements of the rates of frequency changes are available, the search is only in three dimensions instead of the normal five in source frequency, its x-y positions, and speeds. The validity of the new localization scheme of combining frequency and frequency-rate measurements is confirmed with simulation studies. The overall system includes a least-squares track-sort algorithm to differentiate the true track from the extraneous track, and a Kalman tracker for the prediction of future source positions so as to reduce the grid search size. An error analysis relating localization accuracy to uncertainties in frequency measurements and sensor positions is also given. © 1990 IEEE