为了实现对太阳直接光谱辐照度的地基观测,研制了一台用于测量太阳直射光谱辐照度绝对值的扫描式紫外光谱辐射计,工作波段250～400nm,通过太阳跟踪器及二维转台等设备实现地基观测时对太阳的自动跟踪。以NIST标准光源标定了这台光谱辐射计光谱辐照度响应度,定标误差2.4%。在云南丽江地区(26°52′N,100°13′E)开展的地面太阳直射紫外光谱辐照度观测试验进一步检验了仪器的性能。结果表明:时间、云量和大气气溶胶等因素对抵达地表的太阳直射紫外光谱辐照度有直接的影响。 In order to realize the direct spectral irradiance observation of the sun, a scanning ultraviolet spectroradiometer was developed for measuring the absolute irradiance of direct solar radiation. The working wavelength range was 250-400 nm. The solar tracker and two-dimensional turntable Such as equipment to achieve the foundation of the sun when the automatic tracking. The spectral irradiance response of this spectroradiometer was calibrated with a NIST standard light source with a calibration error of 2.4%. Observations of the solar irradiance at the surface of the earth in Lijiang, Yunnan (26 ° 52’N, 100 ° 13’E) further examined the performance of the instrument. The results show that time, cloud amount and atmospheric aerosol have a direct impact on the irradiance of direct sunlight reaching the earth’s surface.