ABSTRACT
The functional relation between the passively measured delay parameters and any one of the desired source location parameters, that is, range or bearing, is nonlinear. The nonlinearity induces a biased estimate of range and bearing whenever noise corrupted time delays are used. A simple bias compensation scheme is applied that removes the bias from the snapshot estimates of range and bearing. This chapter develops an improved snapshot estimate of source bearing and range with significantly less bias than would be obtained when simply using the estimated delays in the equations relating direction and range to true delays. It sets the stage for the formulation of a linear tracker of source range, bearing, down-range rate, and bearing rate that uses the now compensated bearing and range estimates as inputs vs. the commonly used extended Kalman filter which relies on the measured delays as inputs.
