A generalized target description and pulse time-of-arrival estimation

An iterative method that combines a parametric channel model with the maximum likelihood and cross-correlation estimation techniques has been developed to estimate the reflection, creeping wave, and times-of-arrival from an echo emanating from a rigid acoustic sphere. The modeled echo is assumed to have a generalized form, i.e., it is more complex than a linear combination of delayed and scaled versions of the transmitted pulse. Experimental results demonstrate that the algorithm is successful in determining the proper time delays of the reflection and the creeping wave for a variety of received signal-to-noise ratios (SNRs).