无方位模糊的非均匀稀疏阵MVDR测向方法  

MVDR based unambiguous direction finding method for non-uniform sparse array

作　　者：李倩茹[1] 宋志杰[1] 王良[1] 杨晴[1] 

机构地区：[1]中国海洋大学信息科学与工程学院,山东青岛266100

出　　处：《声学技术》2015年第5期389-394,共6页Technical Acoustics

基　　金：声场声信息国家重点实验室基金(SKLA201406)

摘　　要：稀疏阵能够获得更大的阵列孔径,但常规波束形成(Conventional Beam-Forming,CBF)对非均匀稀疏阵测向时会出现方位模糊。提出了一种基于最小方差无畸变响应(Minimal Variance Distortionless Response,MVDR)同局部非稀疏的非均匀稀疏阵(Non-Uniform Sparse Array,NUSA)的设计相结合来抑制方位模糊的方法(NUSA+MVDR),对其无方位模糊现象进行了理论分析,表明MVDR这一非线性处理方法对伪峰有很好的抑制能力。针对一种典型的NUSA(Typical NUSA,TNUSA),进行了TNUSA+MVDR数值仿真实验,其结果和理论分析一致,表明:1 MVDR有很强的NUSA检测能力,在所给仿真条件下,等效阵元间距为50倍波长时,仍能很好地抑制方位模糊;2TNUSA+MVDR较阵元数相同的均匀非稀疏阵列的CBF和MVDR有更高的方位分辨力;3阵元数一定,TNUSA+MVDR方位分辨力随着等效间距增加而提高,最小可分辨角度反比于等效间距;4等效间距一定,TNUSA+MVDR方位分辨力随阵元数增加而增加。海上实验在等效阵元间距为10倍波长条件下部分验证了NUSA+MVDR的检测性能。Sparse array can get large aperture, but it will also lead to azimuth ambiguity if conventional beam-forming（CBF） is used for non-uniform sparse array. In order to solve this problem, the method called NUSA＋MVDR is presented, in which minimal variance distortionless response（MVDR） is applied to non-uniform sparse array with local non-sparse element distribution（NUSA）, and theoretical analysis indicates that false peaks could be suppressed by this method. For a typical NUSA（TNUSA）, numerical simulations are carried out, and the results, which are in good agreement with theoretical analysis, show that： 1. MVDR has great detection performance, as the equivalent element spacing reaches to 50 times of the wavelength under the simulation condition given in this paper, TNUSA＋MVDR can still suppress azimuth ambiguity perfectly; 2. Azimuth resolution of TNUSA＋MVDR is higher than that of CBF and MVDR for a uniform non-sparse array with the same number of elements; 3. For the given number of array elements, the azimuth resolution of TNUSA＋MVDR improves with the increase in equivalent element spacing, and the minimum resolvable angle is inversely proportional to the equivalent element spacing; 4.For the given equivalent element spacing, the azimuth resolution of TNUSA＋MVDR improves with the increase in the number of array elements. The detection performance of NUSA＋MVDR is verified partially by marine experiments under the condition where the equivalent array element spacing is 10 times of the wavelength.

关 键 词：非均匀稀疏阵 最小方差无畸变响应 被动测向 

分 类 号：O427[理学—声学]