Fast Range and Doppler Estimation for Narrowband Active Sonar

In this paper, we present a computationally simple algorithm suitable for fast, high resolution estimation of time delays and doppler shifts (which are necessary for target localization and tracking) between narrowband signals in an active sonar system. The algorithm uses a modulated Lagrange interpolation filter and an LMStype algorithm. The problem of delay and doppler estimation is reduced to a linear regression problem. Convergence and performance analysis of the method is studied both analytically and through simulation. It is demonstrated that the method provides estimates close to the Cramer-Rao Lower Bound