Extended-image reconstruction through horizontal path turbulence using bispectral speckle interferometry
Extended-image reconstruction through horizontal path turbulence using bispectral speckle interferometry
复制标题
使用双谱散斑干涉测量法通过水平路径湍流进行扩展图像重建
DOI：
10.1117/12.56083
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
E. Johansson
中科院分区：
文献类型：
--
作者：
T. Lawrence;J. Fitch;D. Goodman;N. A. Massie;R. J. Sherwood;E. Johansson
结果是从一个水平路径成像实验中，0.5米的望远镜集中在目标位于1.2公里的范围。这些目标的复杂程度各不相同，从简单的二进制字母到具有灰度和大小变化的卫星扩展表示。在中心波长为0.7 μm的成像中，我们发现平均大气退化因子D / r 0 = 17。我们使用了一个缓慢的读取速率裸CCD探测器，因此必须有效地处理加性噪声的散斑测量。我们的图像重建算法的基础上使用的复杂的双谱，我们已经证明了衍射限制成像的光级接近每个斑点每个分辨率区域的几个光子。我们已经仔细注意到加性噪声对重建过程的影响，并表明它们可以被充分克服。这些结果支持了利用CCD对高轨卫星进行高分辨率散斑成像的可行性。
Results are presented from a horizontal path imaging experiment in which a 0.5-m telescope was focused on targets located at a range of 1 .2 km. The targets varied in complexity from simple binary letters to extended representations of satellites with gray scale and size variations. Imaging at a center wavelength of 0.7 μm, we found an atmospheric degradation factor of D / r 0 = 17, on average. We used a slow read-rate bare CCD detector and thus had to deal effectively with additive noise in the speckle measurements. Our image reconstruction algorithms are based on the use of the complex bispectrum, and we have demonstrated diffraction-limited imaging down to light levels approaching a few photons per speckle per resolution area. We have paid careful attention to the effects of additive noise on the reconstruction process and have shown that they can be adequately overcome. These results support the feasibility of high-resolution speckle imaging of high-earth-orbit satellites using CCDs.