利用LANDSAT-5的TM对CBERS-2的CCD1~4波段进行交叉定标,得到了CCD1~4波段的参考辐射定标系数,并对这组定标系数进行了验证.利用6S模型和同步气象资料,对CBERS-2的CCD数据,进行了大气校正和反射率反演.最后对CCD1~4波段大气校正前后的反射率和归-化植被指数(NDVI)的变化进行了对比研究.发现大气校正后的CCD3和CCD4波段的地面反射率明显升高,大气校正后的CCD图像呈现出高植被覆盖区NDVI增大,低植被覆盖区NDVI减小的趋势.
A group of reference calibration coefficients for CBERS-2' s CCD data were provided by cross calibration method by using LANDSAT-5 TM data. The validation for the cross calibration shows its feasibility. A method, which is based on 6S model and isochronous meteorological information on sensing time, was used in the atmospheric correction of CBERS-2' s CCD four bands. Validation analysis was conducted by comparisons of corrected and uncorrected reflectance data including normalized difference vegetation index (NDVI). It finds that the corrected reflectance of CCD3 and CCD4 increases clearly and the NDVI of vegetation ascends while the NDVI of nonvegetation descends.