由于天文观测领域大部分自适应光学系统只能在夜晚工作，提出了采用偏振滤波技术抑制天光背景的办法以达到白天探测微弱星体目标的目的。介绍了偏振滤波的原理并估算了抑制天光背景的效果，通过观测角度关系得到了偏振方位角的计算公式，并在丽江观测站1.8 m望远镜自适应光学系统平台上进行实验，给出了消像旋模型。实验结果表明，偏振滤波技术能有效抑制天光背景，提高星体目标探测能力，一定程度上提高了自适应光学系统在白天探测弱小星体目标的可能性。

Most of adaptive optics systems work in nighttime. Polarization filter technique is applied to suppress sky background for detecting the weak objects in daytime. The theory of polarization filter is introduced. Different kinds of polaroid sheets are placed between the adaptive optics system and the secondary mirror of 1.8 m telescope in Lijiang observation station. Experimental results indicate that polarization filter technique can suppress sky background light effectively and improve the detectability of adaptive optics system. It is shown that polarization filter technique can be used for observing the stellar stars in daytime.