Research On Fast Joint Estimation Of Array Shape And DOA For Short Towed Line Array

With the fast development of maneuvering platforms such as autonomous underwater vehicles and unmanned surface vehicles,it is of great significance to research on direction of arrival(DOA)estimation of the short towed line array.During maneuvering,the bending of the towed line array leads to the degradation of the performance of the target DOA estimation.Therefore,this thesis focuses on the joint estimation of array shape and DOA based on sparse Bayesian learning(SBL)and convolutional neural network(CNN).Based on the study of the spatial matrix filtering to suppress the platform radiation noise,the short towed line array is modeled with a circular arc model,and the adaptive bow sparse Bayesian learning(ABSBL)algorithm is used for the joint estimation of array shape and DOA to reduce the effect of array mismatch.The ABSBL-Prune algorithm and the ABSBL algorithm based on Gaussian generalized approximate message passing(GGAMP)are proposed and used for fast DOA estimation,with the former achieving algorithm speedup through basis vector pruning and the latter solving the posterior mean and variance in ABSBL by approximating to improve the computational efficiency.Both of them solve the problem of inefficiency of the ABSBL algorithm while maintaining high-resolution performance.In order to further improve the performance of DOA estimation of short towed line array and the computational efficiency of the algorithm,the DOA estimation method of deep learning is studied.The DOA estimation model based on the multi-task convolutional neural network(MTCNN)is designed to learn the mapping relationship between the received signal of the towed line array and the DOA through the training data.The covariance matrix of the received signal of the towed line array is used as the model input,DOA estimation is used as the primary task,and bow estimation is used as the secondary task to further improve the performance of DOA estimation.The numerical simulation has verified the performance of ABSBL-Prune,GGAMP-ABSBL,and GGAMP-ABSBL-Prune and the MT-CNN model for high-resolution DOA estimation of the short towed line array.The experimental data of the South China Sea towed line array experiment and the west coast of Italy MAPEX2000 towed line array experiment has demonstrated the effectiveness of each algorithm for the short towed line array DOA estimation during maneuvering.