ABSTRACT
This chapter considers the bearing-time delay statistical relations and defines the impact of increased time delay errors on the form of the bearing estimates. It presents derivation of more general statistical measures on the bearing estimates (bias, variance, Cramer-Rao bound) for unequally separated clusters of hydrophones, unequal variances on the time delay estimates, and correlated delays. This derivation takes into account those differences in spatial and temporal characteristics in the direction finding system to conduct space-time processing of multisensor delay data. The ensued filtering improves the direction finding estimates through reduction of both bias and variance. The relative influence of the various approaches on the quality of the bearing estimates is identified. The resulting net improvement is shown in terms of a reduced bearing bias and variance when compared to varied unweighted combinations of time delay data.
