关联成像是通过对测得的参考光和信号光进行关联计算来获取物体信息的新型成像技术。在复杂环境中，湍流、散射等因素会以噪声的形式影响信号光的测量。由于关联成像中信号光是以桶探测器来测量的，因此，对这种含噪信号光的处理及其在关联成像过程中的影响有必要进行系统地研究。文中系统地回顾了笔者所在课题组在上述背景下的相关研究。首先，简述了复杂环境下的关联成像模型；然后，分析了含噪信号光对二值目标和灰度目标关联成像的影响；接着，对大气信道中湍流引起的信号噪声进行了测量和分析，最后，对关联成像的应用进行了展望。

The scattering medium is usually thought to have a negative effect on the imaging process. In this paper, it is shown that the imaging quality of reflective ghost imaging (GI) in the scattering medium can be improved effectively when the binary method is used. By the experimental and the numerical results, it is proved that the existence of the scattering medium is just the cause of this phenomenon, i.e., the scattering medium has a positive effect on the imaging quality of reflective GI. During this process, the effect from the scattering medium behaves as the random noise which makes the imaging quality of binary ghost imaging have an obvious improvement.

We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness. The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio (SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector’s transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed.