主动目标深度估计一直是主动声呐探测领域的难题。理论推导了目标深度大于收发深度时深海海底反射区目标回波到达结构特征，建立了9路径响应到达结构模型，分析了海底海面反射和海底反射时延差与目标深度之间的关系，提出了基于海底反射区目标回波结构特征的主动目标深度估计方法。基于爆炸声源数据对本文算法开展了验证，通过单水听器得到的水下目标深度估计结果与真实目标深度较为一致，对实验中2.0km至25.6km内20批次目标进行了深度估计，其中17批次深度估计结果误差小于10m，20批次数据深度估计平均误差约为7m。

The discrimination and recognition of underwater targets has been the focus of active sonar detection. The structural characteristics of the target echo arrival in the bottom bounce area are analyzed when the target depth is greater than the transmit-receive depth. A 9-path arrival structure model is established. The relationship between the time delay of the bottom reflected/ surface – bottom reflected path and the target depth is analyzed. A method is proposed to estimate the time delay by searching for target arrival structure in bottom bounce area, and to estimate the target depth by using the relationship between the time delay and the target depth. The algorithm was verified based on explosion sound source data. The estimated depth of the underwater target obtained by a single hydrophone is in good agreement with the real target depth. The depth estimation of 20 targets within 25.6km was carried out, among which the depth estimation error of 17 batches was less than 10m, and the average depth estimation error of 20 batches was about 7m.