基于哈特曼波前传感器的白天天光背景时空特性分析

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关键词：自适应光学；白天天光背景；哈特曼波前传感器；星等；时空特性 中图分类号：O439；TP212 文献标识码：A doi：10.37188/OPE.20253321.3431 CSTR：32169.14.OPE.20253321.3431

Abstract： To address strong sky background interference in daytime adaptive optics （AO） systems，a method is proposed to quantitatively evaluate sky brightness distribution and its impact on observations by calibrating the Hartmann wavefront sensor to compute the equivalent magnitude of the sky background， without introducing additional equipment. Experimental results indicate that the equivalent magnitude of the sky background decreases with increasing solar elevation and with decreasing observation elevation angle; during typical target tracking，sky background brightness can vary by approximately one magnitude at a fixed azimuth. The computed magnitudes exhibit strong agreement with the Kasten-Young linear air mass model. Spatio-temporal analysis of the Hartmann target surface shows that mean grayscale values differ significantly among sub-apertures，while their short-term fluctuation trends remain consistent. The standard deviation of sky background image fluctuations is substantially larger in the spatial domain than in the temporal domain，with an approximate ratio of 1.68. Consequently，efective daytime target observation requires attention to spatial nonuniformity within sub-apertures and implementation of dynamic pixelwise sky background modeling. The proposed method and experiments provide quantitative data to support dynamic parameter adjustment and noise suppression in AO systems，thereby improving daytime observation efficiency and target detection capability.

Key words： adaptive optics； daytime sky background； Hartmann wavefront sensor; stellar magnitude;spatio-temporal characteristics

1引言

自适应光学系统通常工作在晨昏和夜晚，为了拓展自适应光学系统在白天的工作时段，需要克服强烈的天光背景对目标的影响[1-3]。（剩余12902字）