A structure is presented for passive estimation of range, bearing as well as velocity of a source from a linear array. It uses a quasi-optimal post-processor of the time delays, which are obtained from a generalized correlator with finite observation time. The post-processor ultimately maps the sequential time delay observations onto invariant source trajectory parameters over which smoothing is performed to reduce, jointly, the variance and the bias in the estimate of the source kinematics. The present approach remains viable for moving sources at long ranges, off-broadside source directions and high time delay variances. Analysis and simulation results are presented to justify its usefulness under the stated stringent conditions. Review of and comparison to existing approaches are made to highlight the viability of present approach in the estimation of source trajectory.

Ray position in slope-controlled waveguides is studied. A linear combination of three consecutive position measurements is used to calculate the slope error of the middle lens. This is the error input to the middle lens positioning system. Independent lens correction results and thus a decoupling of space and time response is achieved. The system is shown to be stable. Overshoot in the transient response due to cross coupling between controllers is eliminated. Performance is compared to that of the position-controlled waveguide. Computer simulations indicate that the system is stable in the presence of statistical parameter variations.