中文摘要：

研究水下目标优化估算精度问题。在满足对称分布的海洋环境噪声中进行波达方向（DOA）估计的方法对于解决水下目标感知问题有重要意义。由于水下存在的海洋噪声等识别目标难度大,提出了一种重构数据协方差矩阵实部的DOA估计。通过消除数据协方差矩阵实部来降低对称噪声的影响,然后对协方差矩阵实部进行重新构造,恢复损失的目标信息,实现精确DOA估计。与传统方法的比较,方法能够有效降低对称噪声影响,避免双边谱的出现,提高了估计精度。仿真结果表明,方法性能优良,对于海洋环境中DOA估计的研究提供了参考。

英文摘要：

Studying the method of Directions Of Arrival（DOA） estimation in the approximate symmetrical distribution marine environment noise field is of great significance to solve the perceived problem of underwater target.According to the theory that the imaginary part of data covariance matrix has nothing to do with the symmetrical noise component,a new DOA estimation method based on Reconstructing Real-part of Covariance Matrix（RRCM） was proposed.The method first eliminates the real-part of covariance matrix to reduce the symmetrical noise,and then a new real-part is reconstructed so as to restore the lost target information.By doing this,the DOA can be estimated accurately.Comparing with existing methods,the proposed method can effectively reduce the impact of symmetrical noise while the bilateral spectrum does not appear,and the estimation accuracy is improved better.The method achieves a good simulation effect and shows practicability.This work has a positive reference value for DOA estimation in the marine environment.