高轨目标掩星成像相位恢复技术研究

Phase Retrieval Algorithms for Occultation Imaging of Geostationary Satellites

高轨目标掩星成像通过观测高轨卫星对恒星的遮掩过程,实现对高轨目标的成像。该方法采用望远镜线性阵列观测高轨目标遮掩恒星过程中恒星亮度变换,获得高轨目标在地面的投影,通过相位恢复方法可计算得到卫星轮廓图样,具有成像分辨力高,设备制造难度小等优点,在高轨目标成像领域具有较好应用前景。本文分析利用掩星成像方法对高轨目标成像的可行性,重点对掩星成像过程的相位恢复方法进行改进,根据掩星成像特点对输入输出算法进行优化,仿真结果表明:改进后的相位恢复方法可显著提高图像恢复质量和掩星成像方法的空间分辨力。

The silhouettes of geostationary satellites can be obtained by observing their shadow produced by satellite occultation on the ground. An array of telescopes are positioned on the ground for observation of the changes of stellar brightness at the time of the satellite occultation, and the shadow of a satellite can be calculated from observation data. Using phase retrieval algorithm, we can calculate the silhouette of an object from its shadow. Featuring high imaging resolution and cost-effective measurement equipment, occultation imaging has a promising prospect in ima ging of high earth orbit objects. The feasibility of high earth orbit imaging using occultation imaging method is ana lyzed. The highlight is on improvement of the phase retrieval method in the process of occultation imaging. The in- put-output algorithm is optimized based on the characteristics of shadow imaging. Simulation results show that better images are recovered by the phase retrieval algorithm, and the spatial resolution of shadow imaging can be increased by this method.