为了达到在0.4～1.0 μm波段实现绝对不确定度0.05%以内、相对稳定性0.03%/年的太阳绝 对光谱辐照度观测,在太阳绝对光谱辐照度仪研制过程中,入射狭缝光阑的面积需要实现高精度的测量。设计了 激光扫描法和通量比较法相结合的测量方法。测量中以激光-积分球系统作为光源,用高精度trap探测器接收信 号,无需基准光阑,同时突破了激光扫描法测量中对小尺度光阑的限制。对标称为7 mm×0.1 mm光阑 面积的测量中,相对不确定度为4.5×10－4。

In order to achieve the absolute uncertainty which is less than 0.05% and the relative stability which is 0.03% per year in 0.4～1.0 μm of solar absolute spectral irradiance observation, the slit aperture area must be measured with high-precision in the development of solar absolute irradiance spectra-radiometer. The flux comparison method is developed by using laser scanning for precise measurement of the slit aperture area. The laser-illuminated integrating sphere system is used as a light source, and the high-precision trap detector is used to receive signals. Small size apertures can be measured without a reference aperture. In the measurement of the entrance area of solar absolute irradiance spectra-radiometer of which the nominal area is 7 mm×0.1 mm, the total relative uncertainty is about 4.5×10－4.