Improvement of delay measurements from sonar arrays via sequential state estimation

A state-space formulation allows use of Kalman estimation to improve error variance in the measurement of signal delay between sensors by 1) using all-pair measurements, 2) a priori information, and 3) sequential estimation. The formulation is generalized to M sensors in line and results are investigated in detail for M = 3 for extremes of a priori information and measurement error covariance. Use of a priori information for practical range situations gives up to a factor of four error variance improvement. A priori beating information may give more improvement.