中文摘要：

在远场目标的假设前提下，研究了双线阵的CTA算法。推导了理想状态下双线阵常规波束形成的方向指向性函数，分析了理想状态下双线阵延时相加和延时相减两种常规波束形成方法左右舷分辨性能。针对传统的双线阵波束形成方法延时相加和延时相减波束形成空间分辨性能差，而传统的高分辨方法-最小方差无畸变响应（MVDR）计算量大、不易在实际系统得到应用的事实，提出双线阵子阵算法，并给出了双线阵CTA算法的表达式和信号处理流程图。理论研究表明：子阵算法尤其是基于延时相加的CTA算法具有计算量小、波束窄、空间分辨性能好而且还有很好的左右舷分辨性能。最后海试数据验证了理论分析结果的正确性。

英文摘要：

The conventional-then-adaptive （CTA） algorithm was studied considering signals from farfield sources with twin-line array sonnar. The directivity function of conventional beamforming was deduced, and the port/starboard discrimination with the delay-sum and delay-subtract beamformings was studied for twin-line array sonar under the ideal status. The CTA algorithm was proposed, its expression was deduced, and its flow chart was given for twin-line array sonar, taxing aim at the poor space discrimination performance with delay-sum and delay-subtraction beamforrnings, the high cost of computation with the minimum variance distortionless response algorithm which is hardly applied to the practical system in spite of having high resolution. The researched results theoretically show that the CTA algorithm has low cost of computation, narrow beam, high space discrimination performance, high port/starboard discrimination performance. The sea trial results proved the research results to be correct.