空间目标双基地ISAR一维距离像速度补偿方法

Bistatic ISAR Speed Compensation Method for Space Target in One-Dimensional Range Profile

空间目标的高速运动会造成双基地ISAR一维距离像的畸变,针对此问题,研究了相应的速度估计与补偿方法。基于中频直接采样匹配滤波非相参双基地ISAR成像系统,首先研究了高速运动对双基地ISAR成像的影响,其次利用雷达基带回波具有的稀疏性,构造出与高速运动目标回波特性相匹配的冗余基并对其进行稀疏分解,然后据此估计出回波的调频斜率,进而估计出目标的无模糊速度,最后构造补偿相位项完成对宽带回波的速度补偿。算法补偿精度高,且无测速模糊,空间目标理想散点的仿真实验验证了补偿方法的有效性。

High velocity motion of space target can lead to the distortion of one-dimensional range profile in bistatic ISAR.To solve this problem,velocity estimation and compensation method is researched.Based on the imaging system of direct intermediate frequency sampling matching filter non-coherent bistatic ISAR,the imaging influence caused by high speed motion is researched firstly.Secondly,the redundant dictionary matched with high speed motion target echo is created and the echo is decomposed sparsely based on the sparse character of radar baseband echo.Then,the frequency modulation slope of target echo is estimated and target velocity without ambiguity is estimated based on the frequency modulation slope.With the estimated velocity without ambiguity,compensation phase item is created and the speed compensation is finished finally.Compensation accuracy of this method is high and no velocity ambiguity exists.The compensation method is validated by simulation experiment of space target model with ideal scatters.