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利用MODTRAN4模型对地表-大气-遥感器之间的辐射传输过程进行模拟,模拟出对应大气参数下的表观辐亮度;利用模拟生成的大气校正查找表,逐像元对HJ-1卫星CCD数据进行大气校正;并从光谱曲线、与MODIS地表反射率产品比较、归一化植被指数(NDVI)三个方面,探讨了HJ-1卫星CCD数据大气校正效果。结果表明:(1)HJ-1卫星CCD数据的大气校正明显消除了大气在可见光波段的“增加”效应;(2)大气校正后的HJ-1卫星CCD地表反射率数据与MODIS地表反射率产品在植被和居民地的地表反射率上具有很好的一致性,而且大气校正后的HJ-1卫星CCD数据4个波段在这两种地物上的误差大部分不超过20%;(3)大气校正增大了植被NDVI和其他地物NDVI的差值,突出了植被信息。
MODTRAN4 model was used to simulate the radiative transfer between surface-atmosphere-remote sensor to simulate the apparent radiance under the corresponding atmospheric parameters. By using the atmospheric correction lookup table generated by simulation, the CCD data of HJ-1 satellite Atmospheric correction was carried out. Atmospheric correction of HJ-1 satellite CCD data was discussed based on spectral curve, comparison with MODIS surface reflectance products and normalized vegetation index (NDVI). The results show that: (1) Atmospheric correction of HJ-1 satellite CCD data obviously eliminates the effect of “increase” in the visible light band; (2) Atmospheric corrected HJ-1 satellite CCD surface reflectance data and MODIS surface reflection The rate products have a good consistency in the surface reflectance between vegetation and residential areas, and the errors of the four bands of HJ-1 satellite CCD data after atmospheric correction mostly do not exceed 20% on these two kinds of features. 3) Atmospheric correction increases the difference between vegetation NDVI and other features NDVI, highlighting the vegetation information.