基于FLAASH模型的SPOT6卫星影像大气校正及评价

Atmospheric Correction and Evaluation of SPOT6 Satellite Image Based On FLAASH Model

受大气吸收和散射影响,传感器接收到的辐射信息和地表真实反射信息之间存在误差,影响影像的分析精度。选择ORDOS矿区SPOT6卫星多光谱数据,对其进行辐射定标,采用FLAASH模型进行大气校正,对校正前后影像的视觉效果、典型地物反射率光谱曲线、归一化植被指数(NDVI)和植被覆盖度的变化进行对比分析。校正后影像的地物特征更明显、反射率差别较大,能较好还原地表真实信息;NDVI增幅较大,平均植被覆盖度有所提升,能还原较为准确的植被信息。结果表明,FLAASH模型可以有效消除大气影响,对SPOT6卫星影像有较好的校正作用。

Influenced by atmospheric absorption and scattering , the difference between the sensors received radiation information and the surface real reflect information will impact to analysis precision of images .So an atmospheric correction of remote sensing images ,which removes the atmospheric influence ,is an essential part of image processing .SPOT6 satellite multi‐spectral data in ORDOS coalfield is selected to carries on the radiation calibration . Using FLAASH model for the atmospheric correction ,analyzing the visual ,the typical surface reflectance spectral curve ,the normalized difference vegetation index （NDVI） and the vegetation coverage differences between the images before and after correction .It is shown that image feature characteristics is distinctive , reflectivity vary greatly , it can restore the surface real information better ;NDVI is increased considerably ,the average vegetation coverage is increased ,it can restore more relatively accurate information of vegetation .The results show that ,the FLAASH model can eliminate atmospheric effects effectively ,has a good correction effect on the SPOT6 satellite images .