基于改进最大熵谱估计的弹道目标超分辨成像

Hyper-resolution Imaging of Ballistic Targets Based on Improved Maximum Entropy Spectral Estimation

鉴于高频宽带雷达回波信号可采用自回归(AR)模型进行有效拟合的机理,提出了一种弹道目标超分辨逆合成孔径雷达(ISAR)成像方法。该方法首先采用改进的最大熵谱估计方法计算AR模型全局线性预测系数,然后对已有宽带测量数据进行外推预测等效大带宽数据,最后利用距离-多普勒原理进行ISAR成像。利用电磁计算数据进行了实验验证,结果表明,该方法可有效改善弹道目标ISAR成像分辨率,尤其是径向距离分辨率,且计算量小,易于工程实现。

In view of the mechanism that the echo signal of high frequency wideband radar can be fitted effectively by using auto-regression(AR) model, an imaging method of ballistic target super-resolved inverse synthetic aperture radar(ISAR) is proposed spectrum estimation method, then the equivalent large bandwidth data is extrapolated from the existing broadband measurement data, and finally ISAR imaging is performed by using the Range-Doppler principle. The experimental verification is carried out with the electromagnetic calculation data. The experimental results show that this method can effectively improve the ISAR imaging resolution of ballistic targets, especially the radial range resolution.