Modeling Method of Target Echo in Underwater Near Field Based on Highlight Zones-Hightlights Model

To meet the demand for target characteristics modeling of acoustic detection system for underwater weapon in near field, we propose a modeling method of target echo in underwater near field based on the highlight zones-highlights model. Firstly, the target is divided into a series of surface elements in order to ensure each element is located in the far field region of a transducer. Then, the directivity function of the transducer is used to determine the surface elements which are located in the highlight zones of target. Finally, a highlights model is established to achieve the information of target echo by predicting and accumulating the echo of each surface element in highlight zones. A tank experiment is carried out to analog the echoes of an ellipsoidal target in 90°and 30°incidences at side board, and a group of real echoes is achieved. In addition, a simulation is also carried out to compare the results with the experimental ones. It is concluded that the proposed model can simulate the amplitude, time delay and pulse width of the echo effectively, and it can simulate the echo waveform with certain accuracy.