随着科学技术的迅速发展,人们对信息量的需求不断增大。空间激光通信因其具有通信速率高、通信束散角小、 安全保密性高等众多优点,受到越来越广泛的应用。在空间激光通信系统中,天空背景辐射 是影响系统性能的主要背景噪声。强天空背景条件下,粗跟踪光斑的提取成为了影响粗跟踪精度的主要难点。 首先介绍了几种抑制天空背景光的方法,如采用原子滤光片、减小接收机口径等。在实验条件下,采 取Otsu阈值处理和质心算法对粗跟踪光斑进行处理,分析天空背景光对粗跟踪成像光斑的影响。实验结果表明, 在天空背景光影响下,这种Otsu阈值处理方法能够准确提取成像光斑,可以有效提高粗跟踪精度。

With the high-speed development of science and technology, the demand for information is growing rapidly. Space laser communication is used more and more widely due to its advantages, such as faster rate of communication, smaller beam divergence angle of communication and better security and confidentiality. In the space laser communication system, the sky background radiation is the main background noise. Spot extraction has become a major impact on tracking accuracy in strong sky background conditions. Several methods for suppressing sky background were described, such as using atomic filters, reducing the caliber receiver, et al. Under the experimental conditions, coarse tracking spot is processed by using Otsu thresholding and centroiding algorithm. The effects of sky background light on coarse tracking spot are analyzed. The experimental results show that under the influence of the sky background, the Otsu thresholding method can accurately extract imaging spot, it also can effectively improve the coarse tracking accuracy.