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高分一号卫星(GF-1)WFV相机是中国新型高分辨率传感器,为了更好地进行定量应用,需完成高精度大气校正,但需要解决数量大,辅助数据不足等关键问题。针对WFV相机构建了快速大气校正模型,(1)采用交叉定标方法借助Landsat 8数据完成辐射定标;(2)从WFV相机的辅助数据出发,计算得到太阳天顶角、观测天顶角等辅助信息;(3)考虑不同海拔大气分子散射的不同,完成基于海拔数据的分子散射校正;(4)采用深蓝算法,从第一波段(蓝光)反演得到气溶胶信息;(5)计算每个像元的大气校正参数,进而获取地表反射率,完成大气校正。在此基础上,利用IDL语言建立相应的大气校正模块,以过境华北地区的3景WFV数据为例进行大气校正实验。结果表明,模型能够快速完成大气校正,并能较好的去除大气分子与气溶胶影响,较好地还原植被、裸土等典型地表类型的光谱反射曲线,校正后的NDVI更好地反映了各地物的特征。
High-score one satellite (GF-1) WFV camera is a new type of high-resolution sensor in China. In order to carry out quantitative applications better, it needs to complete high-precision atmospheric correction, but it needs to solve the key problems of large quantity and insufficient auxiliary data. A fast atmospheric correction model was constructed for the WFV camera. (1) Radiation calibration was completed by Landsat 8 using cross-calibration method. (2) Based on the auxiliary data of WFV camera, the solar zenith angle and zenith angle (3) the molecular scatter correction based on altitude data is completed considering the scattering of atmospheric molecules at different altitudes; (4) the aerosol information is retrieved from the first wave band (blue light) by using the dark blue algorithm; (5) A pixel atmospheric correction parameters, and then get the surface reflectance, complete the atmospheric correction. On this basis, the atmospheric correction module was built by using IDL language, and the atmospheric correction experiment was carried out with the WFV data of 3 scenes in North China. The results show that the model can quickly complete the atmospheric correction and remove the influence of atmospheric molecules and aerosols well and restore the typical spectral reflectance curves of vegetation and bare soil. The corrected NDVI better reflects Characteristics of things.