面向高轨目标成像的强度相干阵列优化

Amelioration of Intensity Correlation Array towards High-Orbit Satellite Imaging

对高轨目标成像时为减小恢复图像中的噪音,需对相干阵列系统参量进行优化以提高强度相干成像质量.根据强度相干原理分析空间频谱测量噪音和相位恢复噪音产生的原因,在高频探测器数量固定情况下,分析相干阵列的集光面面积、探测器排布间距等参量对成像质量的影响.通过室内实验,研究最优集光面面积和最短观测基线的选取方法.实验结果表明:对于14星等的地球同步轨道卫星,阵列最短基线长度为光场横向相干长度0.61倍,集光面直径为光场横向相干长度的0.46倍时可获得最佳成像效果.对阵列的优化能够提高强度相干成像质量.

In order to reduce the noise of reconstuted image when imaging high orbit satellites with intensity correlation array, research on array amelioration should be done to improve the quality of intensity correlation imaging. According to intensity correlation principle, the reasons of spatial spectrum measurement noise and phase retrieval noise generation were analyzed. Also, the effect of condenser area of intensity correlation array, detector arrangement spacing and other parameters on imaging quality was analyzed in condition that the number of high-frequency detectors was fixed. The selecting methods of optimal condenser area and the observation baseline was discussed by a mockup experiment. As the experiment results indicate： for the 14 Mv geostationary satellite, the optimal image can be obatined when the shortest array baseline length is 0.61 times as long as the transverse coherence length, and the condenser diameter is 0.46 times as long as the transverse coherence length. The intensity correlation imaging quality can be largely improved by array amelioration.