干旱气象

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不同季节下FY-3B/MERSI数据大气校正前后对比

  

  1. 1.陕西省农业遥感信息中心,陕西 西安 710014;
    2.中国石油长庆油田分公司,陕西 西安 710018
  • 出版日期:2015-08-31 发布日期:2015-08-31
  • 作者简介:权文婷(1985-),女,陕西西安人,工程师,硕士,主要从事遥感监测方面的研究.
  • 基金资助:

    国家重点基础研究专项(2013CB429701)和陕西省气象局科技创新基金计划项目(2014M-15)共同资助

Atmospheric Correction of FY-3B/MERSI in Different Seasons and Evaluation

  1. 1.Shaanxi Provincial Agricultural Remote Sensing Information Center, Xi’an 710014, China;
    2. Petro China Changqing Oilfield Company, Xi’an 710018, China
  • Online:2015-08-31 Published:2015-08-31

摘要:

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。

关键词: FY-3B/MERSI影像, FLAASH模型, 大气校正

Abstract:

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 decreasing ranges in autumn and winter were larger than that in spring and summer. However, the reflectance in near-infrared wavelengths increased after atmospheric correction except for the 16 channel in autumn and winter. (3) Compared with the surface reflection 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 habitation after atmospheric correction was larger than that before atmospheric correction, the former between vegetation and habitation increased 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.

Key words:  FY-3B/MERSI image, FLAASH model, atmospheric correction

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