The impact of refraction on time-delay estimation

This paper considers the impact of refracted multipath acoustic energy on time delay estimation (TDE). The objective is to investigate the sensitivity of correlograms to various sound velocity profiles. Our approach involved using the Generic Sonar Model to compute the cross-correlation function for an array of two separated receivers situated in realistic ocean environments. The results were compared with those predicted assuming isovelocity profiles. The influence of the target range and bearing, as well as the vertical separation of the receivers on the correlograms, is demonstrated for each environment considered. Our results indicate that TDE may be significantly impacted by the processing of highly refracted rays of many different types.