摘要
分别概述了微波极化指数、散射指数以及土壤湿度指数等被动微波遥感指数的发展及其应用.37 GHz的微波极化差指数△T37(△T37=TB37v-TB37H)和极化比指数(MPDI=C*(TB37V-TB37H)/(TB37V+TB37H))被认为是监测植被状况的微波植被指数,利用GAME-Tibet1998IOP数据计算和分析了青藏高原中部5个试验站点6～9月的平均△T37值和MPDI值的变化情况.结果表明:ANDUO和MS3608的平均值在15 K左右,表现出裸土的微波辐射特征;总体上5个站点的MPDI随时间的变化不大,也即在1998年6～9月间,各个站点的植被状况变化不大;而站间的差别比较大,也即各个站点的植被状况有较大的差别;ANDUO的MPDI表现出规律性的变化,即在6至9月的变化中,8月份的MPDI最小,对应植被最好的月份;对研究区的MPDI和相应时间的MSAVI(可见/近红外数据得到的修改型土壤调整植被指数)的空间分布图进行了比较,二者基本吻合.
Development and application of passive microwave remote sensing indexes, such as microwave polarization index, scattering index and soil moisture index are summarized in this paper. The values of microwave polarization difference index, △T37 and microwave polarization ratio index, MPDI of five sites in the Central Tibetan Plateau are obtained and analysed from observed data during 1998 IOP, including remote sensing data（TMI data） and in-situ observed data. Results show that： （i） the averaged △T37 values of ANDUO and MS3608 are about 15 K which are characteristics of bare soil; （ii） the values of MPDI at five sites change less with time ,and it means that the vegetation change less from May to September, 1998. The values of MPDI among five sites change more, which means that the vegetations of sites are different; （iii） the values of ANDUO site change according to vegetation growth from May to September, and the lowest values in August responds to the best vegetation; （iv） by comparing the meantime maps of MPDI and MSAVI in the same study area, the vegetation conditions obtained by different data （microwave and optical remote sensed data）are consistent.
出处
《遥感技术与应用》
CSCD
2005年第6期551-557,F0005,共8页
Remote Sensing Technology and Application
基金
中国科学院知识创新项目(2004406)
关键词
遥感指数
被动微波遥感指数
微波极化指数
散射指数
土壤湿度指数
青藏高原
Remote sensing index, Passive microwave remote sensing index, Microwave polarization index, Scattering index, Soil moisture index
