MODIS大气校正精度评价及其对表层雪密度提取影响

以古尔班通古特沙漠为研究区，以中分辨率成像光谱仪（MODIS）为遥感数据源，结合ASD FieldSpec准同步实测积雪反射光谱数据对FLAASH大气校正能力进行了评价。研究表明： ①校正后的MODIS各波段积雪反射率与准同步实测积雪反射率波形相似, 在第1～7波段整体相关系数达0.82，表明FLAASH大气校正能极大地提高MODIS地物识别能力； ②校正后的MODIS 第6波段反射率和归一化差值积雪指数（NDSI）与实测雪密度呈线性相关，可用回归拟合构建MODIS雪密度遥感计算模式。

Accuracy Evaluation of MODIS Atmospheric Correction and Its Effects on Surface-Snow Density Extraction

 With Gurbantunggut desert as the study area and by using moderate resolution imaging spectrometer (MODIS) data, which is a kind of optical remote sensing data，in combination with snow reflectance spectra simultaneously measured by ASD Field Spec, the authors evaluated the correction capability of FLAASH model. Some results have been attained: ① Snow reflectance from 1st to 7th band of MODIS is similar to the simultaneously measured snow reflectivity，and the correlation coefficient of all bands is 0.82 on the whole， indicating that FLAASH can greatly enhance the capability for identifing surface features of M0DIS . ② On the basis of linear relationship between snow reflectance after correction at MODIS channel 6 and NDSI and measured snow density, a snow density remote computation model can be built by way of regression and fitting.