Sound Source Depth Estimation Based on Multipath Time Delay in Deep Water

In deep water, when the minimum time arrivals in all receiver depths are rowed and then fixed on a certain time on time delay-receiver depth plane, time delays of bottom reflection (BR) and surface-bottom-surface reflection (SBS) have a linear relationship with the receiver depth under the approximation condition. Besides, time delay arrivals of BR and SBS intersect at a receiver depth which is equal to the negative source depth. Based on the feature, a source depth estimation method with the multipath time delay difference is proposed. If the depths of receivers which are deployed vertically are known, the pair of time delays can be used to estimate the source depth. With the proposed method the source depth can be estimated successfully at a moderate range in deep water without complicated matched-field calculations in the simulations and experiments.