太阳辐照度测量中孔径光阑衍射效应

Aperture stop diffraction effect of solar irradiance measurement

针对当前在辐照度测量中对孔径光阑衍射效应的评估仍停留在理论计算层面,无法评估衍射修正结果不确定度的现状,研究了光阑衍射效应实验检测方法,以校正孔径光阑的衍射效应并提升太阳总辐照度的测量精度。基于暗场成像技术和夫琅和费远场衍射理论,设计孔径光阑的衍射效应检测方法,开展检测实验,通过研究探测器线性度标定、背景信号校正、衍射图像数据分析等,建立数据修正处理流程,获取孔径光阑在前结构的太阳绝对辐射计衍射效应值,并对实验结果进行不确定度分析。测试结果显示:衍射效应测量值为8.81×10^(-4),合成不确定度为6.49%。研究成果将为我国下一代风云气象卫星太阳辐射监测仪衍射效应的精确校正及实现高精度太阳总辐照度的测量奠定关键技术基础。

To address the current reliance on theoretical calculations for evaluating the diffraction effects of aperture stops in irradiance measurement,an experimental method to detect diaphragm diffraction effects was developed.This aims to correct aperture stop diffraction and enhance total solar irradiance measurement accuracy.Utilizing dark-field imaging and Fraunhofer far-field diffraction theory,a detection method was designed and tested.By calibrating detector linearity,correcting background signals,and analyzing diffraction image data,a data correction process was established.This process determined the solar absolute radiometer diffraction effect value at the aperture stop's front structure and assessed the experimental uncertainty.The experiment found a diffraction effect value of 8.81×10^(-4) with a total uncertainty of 6.49%.These findings provide a crucial technical foundation for accurately correcting diffraction effects in China's next-generation Fengyun meteorological satellites'solar radiation monitors,enabling precise total solar irradiance measurements.