摘要
根据MODIS卫星第18和19波段的波段特征,首先从理论上证明从这两个波段表观反射率的比值反演大气可降水量的可行性,其次利用MODTRAN模型按照中纬度冬季和夏季两种大气模式对该比值与大气水汽的关系进行模拟,并建立了反演大气水汽的公式。利用贵州地区高空探测数据对反演公式进行验证,并与EOS发布的MODIS近红外水汽反演结果进行比较,发现该公式的反演结果更接近实际探测的结果。由于在反演过程中不必考虑地表覆盖和反射率的差异,摆脱了传统的根据查找表反演水汽的方式,并且直接由18、19波段表观反射率的比值计算大气可降水量,相对于传统算法更易于业务化运行。
Precipitable Water Vapor （PWV） derived from the ratio of the apparent reflectance values of the 18th and 19th bands of Moderate Resolution Imaging Spectrum-radiometer （MODIS） is introduced. The relation of the ratio and the PWV value lies in the formula set up by MODTRAN simulation. Comparing with EOS PWV products and local radiosonde data in the Guizhou Province which is considered as the true PWV value, the results show that the method could be applied under the condition of cloudless （PWV 〈7 cm ）, and the retrieval precision is better than the retrieve method which EOS adopted presently. The surface coverage and difference of reflectance in the process of retrieve isn＇t considered, the method is direct to calculate the PWV by the ratio of the apparent reflectance values of the 18th and 19th bands so that it＇s more easier to regular operation than other tradition arithmetic.
出处
《高原气象》
CSCD
北大核心
2009年第2期446-451,共6页
Plateau Meteorology
基金
国家自然科学基金项目(40765004)
贵州省省长专项资金项目(2005Z267,2008Z70)
贵州气象创新项目(2008-IP02)共同资助
关键词
贵州高原
遥感
MODIS
表观反射率
大气水汽
Guizhou Plateau
Remote sensing
MODIS
Apparent reflectance
Atmospheric column water vapor
