面向高轨目标的强度相干成像技术研究

Intensity Correlation Imaging Technology for High Earth Orbit Objects

强度相干成像技术是指利用地基强度相干阵列测量空间目标光强随机涨落的相干性,可获得目标的空间频谱模值,结合目标先验信息即可恢复目标光强分布图像。这种成像方法具有成像分辨力高、设备精度要求低、受大气湍流影响小等优点,目前已应用于恒星目标的成像观测领域,是一种有发展前景的地基光学成像手段。在综述强度相干技术原理与发展历程基础上,分析了利用强度相干阵列对高轨目标成像的可行性,认为在利用强度相干阵列对高轨目标成像过程中,主要存在空间频谱探测信噪比低和相位恢复复杂2大难题,提出利用激光主动照明对目标进行探测,同时采用符合计数方法和正则化优化方法可提高探测信噪比与相位恢复质量,对实现高轨目标成像有一定参考。

Intensity correlation imaging is a high-resolution-imaging technology, in which the intensity fluctuations of incoherent luminary were measured by the ground-based intensity interferometry array, and the modulus of spatial coherence were calculated by the correlation of intensity fluctuation from different field point,by which the intensity distribution of the target can be acquired using phase retrieval algorithm. This high-resolution imaging method is immune to atmospheric turbulence and apparatus＇ deviation, it has been used in stellar imaging for a long time . This paper introduced the basic theory and development of intensity correlation technology. The feasibility of geostationary satellite imaging by intensity interferometry array was analyzed. We deemed that the low measuring signal-noise ratio of spatial coherence and the ambiguity of phase retrieval are the main obstacles of intensity correlation imaging, laser Illumination, coincidence-counting as well as optimized regularization would solve these problems and make it possible to image the geostationary satellite using intensity correlation method.