地表反照率是研究陆地辐射收支情况、区域及全球气候、地貌等信息的先决条件,对其进行精确测量是开展相关研究的前提和保证。由于大气层吸收的影响,地表反照率不能进行直接测量。因此,采用测量垂直向下与向上散射光的方法,结合SCIATRAN辐射传输模型获得地表反照率。基于此方法,在机载平台上进行观测实验,获取机载平台上垂直向上和向下的辐亮度值,采用迭代反演方法获得石家庄到保定地区紫外波段350~395 nm的地表反照率,并对不同下垫面、不同波段反照率进行比较,对城区中心到边缘过渡变化进行详细分析。结果表明,紫外波段350~395 nm地表反照率随波长增大而缓慢升高,结果与中等分辨率成像光谱仪(MODIS)数据可达到良好的一致性。不同观测区域结果对比显示,城区地表反照率大于农田,且城区中心比边缘地表反照率大0.014左右,其差异也随波长增大而升高。

The surface albedo is a prerequisite for the research of the information such as land radiation budget, regional and global climate, and geomorphology. Therefore, its precise measurement is the premise and guarantee of relevant research. Due to the influence of atmospheric absorption, the surface albedo cannot be directly measured. Therefore, the method of measuring vertical downward and upward scattered light and combining SCIATRAN radiative transfer model is adopted to obtain the surface albedo. Based on this method, the observation experiment is carried out on the airborne platform. The vertical downward and upward radiance values are obtained. The iterative retrieval method is used to obtain the surface albedo of the area from Shijiazhuang to Baoding in the ultraviolet band from 350 nm to 395 nm. And the surface albedos of different underlying surfaces and different bands are compared. The transition from the center to the edge of the city is analyzed in detail. The results show that the surface albedo of ultraviolet waveband ranging from 350 nm to 395 nm goes up slightly with the increase of the wavelength, which is in good agreement with medium resolution imaging spectrometer (MODIS) data. In addition, the comparison of different observation areas shows that the surface albedo of urban area is larger than that of farmland, and the surface albedo of the center of the city is about 0.014 higher than the edge of the city. The difference also goes up with the increase of the wavelength.