基于速度合成孔径雷达的海面舰船动目标成像方法

Imaging of moving surface ships based on velocity synthetic aperture radar

海面舰船成像技术在军事和民用领域应用广泛。针对海面动目标成像定位模糊的缺点,提出了使用速度合成孔径雷达(velocity synthetic aperture radar,VSAR)估计动目标速度频率的方法。首先,分析了VSAR的成像机理和限制条件,建立了基于相控阵雷达对海面舰船的成像模型;然后,采用多天线图像域的速率频率估计方法纠正方位向的偏移,采用图像熵算法完成目标图像的自适应聚焦;最后,利用该方法对海面运动舰船进行仿真计算。仿真结果表明,VSAR在处理大海域海面静动目标同时存在的场景下,可以甄别出目标所属类型,判断出动目标的运动趋势和航行轨迹。相比于传统的单通道SAR雷达和沿航迹干涉雷达算法,速度频率估计算法解决了方位定位精度不足的缺点,提高了大面积海域条件下的动目标舰船的定位性能,具有良好的应用前景。

Surface ship imaging technology is widely used in military and civilian applications.To resolve the problem of imaging target positioning blur on sea surface,this paper proposes a method for estimating the velocity of the moving target using velocity synthetic aperture radar(VSAR).Firstly,this paper analyzes the imaging mechanism and constraints of the VSAR method,and establishes an imaging model based on phased array radar for surface ships.Then,the rate frequency estimation method of the multi-antenna image domain is used to correct the azimuth offset,and the image moisture algorithm is used to complete the adaptive focusing of the target image.Finally,this method is used to simulate the moving ship on the sea.The simulation results show that VSAR can identify the type of target and judge the moving trend and trajectory of the moving target when dealing with the simultaneous existence of static and dynamic targets on the sea surface in large sea areas.Compared with the traditional single channel SAR and the along track interferometer algorithm,the rate frequency estimation algorithm solves the shortcomings of the azimuth positioning accuracy,and improves the positioning performance of the moving ship under large area sea conditions,and has good application prospects.