TARGET TRACKING WITH A NETWORK OF DOPPLER RADARS

By observing a Doppler signal at several points in space, it is possib le to determine the position, velocity, and acceleration of a moving t arget. Parameter identification for a constant-acceleration motion mod el is studied, and the Cramer-Rao bound on motion parameter uncertaint y is obtained for phase-and frequency-based estimation strategies, wit h the result that the preferred strategy depends upon the sensor/targe t geometry and target motion. Direct identification of the constant-ac celeration trajectory model from the Doppler signal requires a 9-dimen sional nonlinear optimization. Exploiting symmetry in the sensing geom etry, a novel trajectory representation is presented which reduces the nonlinear optimization to one in 3 dimensions, with additional parame ters obtained by linear identification. Baseball tracking using a netw ork of four Doppler radars is experimentally demonstrated.