多子阵合成孔径声呐6阶方位空变运动补偿快速算法

A fast algorithm based on a sixth-order azimuth variance model for multi-receiver synthetic aperture sonar motion compensation

为解决6自由度运动误差存在情形下的多子阵合成孔径声呐快速运动补偿与成像问题,本文提出一种多子阵合成孔径声呐6阶方位空变运动补偿快速算法。在考虑6自由度运动误差随方位时间6阶空变特性的基础上,对双根号形式距离历程进行泰勒级数展开并保留至6阶项,进而推导得到严格解析的点目标响应二维谱,通过对传统四阶模型的距离多普勒算法进行改进,同时实现了6自由度运动误差的快速补偿和图像重建。仿真分析和实测数据成像结果表明了所提算法的有效性和高效率,可为大场景宽测绘带多子阵合成孔径声呐快速运动补偿和高分辨成像提供理论依据。

To solve the problem of fast motion compensation and imaging in multi-receiver synthetic aperture sonars(SASs)with six degree-of-freedom(DOF)motion errors,we propose a fast algorithm based on a sixth-order azimuth variance model for compensating motion errors.Considering the sixth-order spatial variation characteristics of the six DOF motion errors over azimuth time,we use a Taylor series expansion of the range history in a double square root form,retaining up to the sixth-order terms.This approach enables us to derive a strictly analytical twodimensional spectrum of the point target response.We then improve the range-Doppler algorithm,which previously accommodated fourth-order models,to handle these higher-order terms.This improvement enables simultaneous fast compensation and image reconstruction for six DOF motion errors.Our simulation analysis and real data imaging results show the effectiveness and efficiency of the proposed algorithm.It provides a solid theoretical foundation for fast motion compensation and high-resolution imaging in multi-receiver SAS with large scene widths.