用多子阵空间互相关矩阵估计合成孔径声呐基阵速度
Utilizing the multiple-receiver spatial mutual correlation matrix to estimate the velocity of synthetic aperture sonar array
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摘要: 受接收子阵长度的影响,单纯依靠重叠相位中心的合成孔径声呐(Synthetic Aperture Sonar,SAS)基阵速度估计方法的精度较低。为此,提出一种利用多子阵空间互相关矩阵的方法以提高速度估计精度。通过SAS多子阵回波数据构造空间互相关矩阵(Spatial Mutual Correlation Matrix,SMCM),利用Radon变换和SMCM系数分布精确估计重叠相位中心对直线(Line of Displaced Phase Center Pairs,LDPCP)参数,并利用重叠相位中心对速度关系式估计SAS基阵速度。对高低频SAS试验数据应用的结果表明:该方法可有效地消除接收子阵长度的影响,将基阵速度估计的精度提高3~5倍,满足高频和低频SAS系统成像的要求。Abstract: Affected by the length of the receiving element,the method utilizing displaced phase center to estimte the velocity of Synthetic Aperture Sonar(SAS) array suffers the low precision problem.Therefore,a method utilizing the multiple-receiver Spatial Mutual Correlation Matrix(SMCM) is proposed to improve the velocity estimation precision. The SMCM is built by the multiple-receiver raw echo data.Then,the parameters of the Line of Displaced Phase Center Pairs(LDPCP) are estimated based on the Radon Transform and the distribution of the SMCM coefficients.At last,the velocity of the SAS array is calculated by the DPCP velocity estimation formula.The method was applied to high and low frequency SAS system.Resultsshow that the effect of the length of the receiving element is eliminated effectively, the precision is improved 3 ~ 5 times and the method can fulfill the requirements of the high frequency and the lowfrequency SAS imaging.
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