非均匀转动目标ISAR成像及横向定标

当目标在平面内非均匀转动时，传统算法不能获得包含定标信息且聚焦良好的ISAR像。为解决这一问题，提出了一种非均匀转动目标的转动参数估计方法。该方法首先通过一维搜索对角加速度与角速度的比值进行估计，并根据估计结果对原始距离像序列进行非均匀采样，补偿角加速度引起的相位误差，从而得到聚焦的ISAR像；然后根据成像质量准则对重采样距离像序列的角速度进行一维搜索，估计出角速度，进而实现ISAR像的横向定标。仿真结果表明:该算法通过2个一维搜索能得到非均匀转动目标聚焦的、横向定标的ISAR像。

ISAR Imaging and Cross Scaling for Non-uniform Rotating Targets

The use of traditional algorithms cannot obtain a well-focused and cross scaled ISAR image for non-uniform rotating targets. To solve this problem, a method is proposed to estimate the rotating parameters when targets undergo non-uniform rotation. Firstly, the ratio between the angular acceleration and the angular velocity is estimated by one dimension search. By non-uniformly sampling the raw profile sequence according to the estimated ratio, the phase error caused by angular acceleration can be compensated and a focused ISAR image can be obtained. Based on the rule of image quality, the rotating velocity of the resample signal can be estimated by another one dimension search. Furthermore, the scalar of cross-range can be obtained. A focused, cross-range scaled ISAR imaging can be obtained for non-uniform rotating targets based the proposed algorithm. Experimentations with the simulated and measured ISAR data demonstrate the effectiveness of the algorithm.