CAJ | 학술논문

应用FLAASH模型对FY-3B/MERSI数据进行大气校正，并从大气校正前后反射率变化、NDVI和EVI变化及其与MODIS地表反射率产品比较等4方面对校正效果进行讨论分析，以期提供一种行之有效的FY-3B/MERSI数据大气校正方法。结果表明：（1）校正后削弱了大气分子与气溶胶在可见光波段的散射影响，且各通道反射率区间变宽；（2）除红光波段外，可见光其余波段各通道大气校正后的反射率均有所减小，且秋、冬季比春、夏季影像反射率减小幅度更大；对于近红外波段，除秋、冬季第16通道外，大气校正后的反射率均有所增加；（3）与MODIS地表反射率产品相比较，FY-3B/MERSI校正后的反射率与MYD09GA产品的误差均小于校正前，校正后的植被和居民地2种地物的反射率比校正前更具有较好的一致性；（4）校正后，植被与居民地的NDVI和EVI均有所增大，且NDVI较EVI增加的幅度大，同时校正前后两者的NDVI、EVI差值均增大，表明FY-3B/MERSI影像经大气校正后更有利于植被与非植被信息的区分。
응용FLAASH모형대FY-3B/MERSI수거진행대기교정，병종대기교정전후반사솔변화、NDVI화EVI변화급기여MODIS지표반사솔산품비교등4방면대교정효과진행토론분석，이기제공일충행지유효적FY-3B/MERSI수거대기교정방법。결과표명：（1）교정후삭약료대기분자여기용효재가견광파단적산사영향，차각통도반사솔구간변관；（2）제홍광파단외，가견광기여파단각통도대기교정후적반사솔균유소감소，차추、동계비춘、하계영상반사솔감소폭도경대；대우근홍외파단，제추、동계제16통도외，대기교정후적반사솔균유소증가；（3）여MODIS지표반사솔산품상비교，FY-3B/MERSI교정후적반사솔여MYD09GA산품적오차균소우교정전，교정후적식피화거민지2충지물적반사솔비교정전경구유교호적일치성；（4）교정후，식피여거민지적NDVI화EVI균유소증대，차NDVI교EVI증가적폭도대，동시교정전후량자적NDVI、EVI차치균증대，표명FY-3B/MERSI영상경대기교정후경유리우식피여비식피신식적구분。
Based on the FY-3B/MERSI images,MYD09GA products from MODIS and visibility from weather station in Shaanxi,the FY-3B/MERSI images on 26 April,10 July,16 November 2012 and 9 January 2013 were corrected by FLAASH model. And on this basis the results of MERSI before and after atmospheric correction were comparatively analyzed,including the reflectivity,NDVI and EVI of MERSI before and after atmospheric correction,and the difference of reflectivity between MERSI before and after atmospheric correction and MYD09GA. The results are as follows:(1)The scattering effect of atmospheric molecules and aerosols was weakened in visible wavelengths after atmospheric correction and the intensity of scatter decreased with the wavelengths,and the ranges of reflection in each channel were obviously widened,which indicated that the phenomenon of different objects with same spectrum was eliminated. (2)Except red bands,the reflectance in invisible wavelengths after atmospheric correction decreased in different seasons,and the de-creasing ranges in autumn and winter were larger than that in spring and summer. However,the reflectance in near-infrared wave-lengths increased after atmospheric correction except for the 16 channel in autumn and winter.(3)Compared with the surface reflec-tion of MODIS,the differences of FY-3B/MERSI after atmospheric correction were smaller than that before atmospheric correction, and the reflectance of vegetation and residential area after atmospheric correction was well consistent with MYD09GA than that before atmospheric correction.(4)The values of NDVI and EVI for vegetation and habitation areas after atmospheric correction increased, and the increasing of the former was higher than the latter. Furthermore,the differences of NDVI and EVI between vegetation and habi-tation after atmospheric correction was larger than that before atmospheric correction,the former between vegetation and habitation in-creased from 0. 1828 to 0. 2211 and the latter increased from 0. 0232 to 0. 0251,which would be beneficial to distinguish vegetation and non-vegetation in image classification.