基于子孔径参数估计的双基地ISAR图像融合方法研究

Research on Image Fusion Based on Sub-aperture Parameter Estimation for Bistatic ISAR

双基地逆合成孔径雷达(Bistatic ISAR)能够同时获取两个视角下的目标雷达回波,将分别所成的图像进行融合处理可以获得质量更高的ISAR图像以提供更丰富的目标信息,但由双基地角带来的目标像尺寸形状不一致等问题将造成融合困难。该文针对转台模型目标,提出一种基于子孔径参数估计的双基地ISAR图像融合方法,利用孤立强散射点在不同子孔径下的多普勒差值估计出目标的转动角速度和半双基地角,再将不同视角下的数据映射到同一个坐标平面中进行融合处理,得到效果更好的图像,最后利用仿真实验结果验证了该方法的有效性。

Bistatic ISAR systems can receive echoes from different observation angles simultaneously,thus a finer image with more abundant information of a certain target can be obtained by fusing the two images attained with bistatic radars.However,the dis-match of dimensions and shapes of the two target images caused by bistatic angle highly complicates the image fusion process.This paper,based on the bistatic ISAR turn table model,proposes an ISAR image fusion method based on sub-aperture parameter estimation.The algorithm first extracts the Doppler difference between two sub-apertures of an isolated prominent scattering point to estimate the Rotation Velocity（RV） and half bistatic angle,then maps the two data sets from different observation angles onto a global coordinate system to perform the image fusion process,resulting in an ISAR image of higher quality.Finally,simulation experiments are provided to demonstrate the effectiveness of the method proposed.