摘要
目前基于被动微波遥感技术的地表冻融变化监测对垂直剖面内表层土壤温度的差异考虑较少。该文从判别算法和多层土壤温度差异性两方面进行分析,结果显示:1)基于准发射率和基于亮温标准差的冻融判别算法的判别结果均与1 cm表层土壤地面监测结果吻合率最高,表明被动微波冻融产品的验证应尽可能使用最靠近地面的土壤层温度,两种算法在1~5 cm不同深度表层土壤的验证中均显示出较大差异;2)土壤表层温度在0 cm和5 cm深度处的相关性极好,但在冻融判别阈值0℃附近存在较大差异,该差异是导致判别误差的重要来源。研究结果对于地表冻融参量的定量化、精细化遥感监测研究具有理论意义和应用价值。
In previous studies about land surface freeze-thaw monitoring based on the passive microwave remote sensing technique,little consideration has been given to the difference in the inner surface soil temperature on the vertical profile.In this paper,the analysis was done from the perspective of discriminant algorithm and the validation data of multi-layer soil temperature,respectively.From the perspective of discriminant algorithm,it was found that the discrimination results of the freeze-thaw discriminant algorithm based on quasi-emissivity and that based on the standard deviation of bright temperature were most consistent with the observation results of surface soil temperature at 1 cm depth.This suggested that the top layer of surface soil(with the depth of 1 cm)should be selected when doing the test of passive microwave freeze-thaw products.Nonetheless,the two algorithms showed large difference when tested using multi-layer soil temperatures in the range of 1 cm to 5 cm.From the perspective of validation data,it was found that there is a very good correlation between the soil temperature at the surface layer depth of 0 cm and the depth of 5 cm,but there is a big difference near the freeze-thaw discrimination threshold of 0℃,which is an important source of discrimination error.This study has important theoretical significance and applications for the quantification and refinement of the remote sensing monitoring of surface freeze-thaw parameters.
作者
寇晓康
张玉芝
靳梦杰
彭晓炜
张良
KOU Xiao-kang;ZHANG Yu-zhi;JIN Meng-jie;PENG Xiao-wei;ZHANG Liang(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043;Key Laboratory of Roads and Railway Engineering Safety Control (Shijiazhuang Tiedao University),Ministry of Education,Shijiazhuang 050043;Hebei Key Laboratory of Structural Health Monitoring and Control,Shijiazhuang Tiedao University,Shijiazhuang 050043;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《地理与地理信息科学》
CSCD
北大核心
2020年第3期49-55,共7页
Geography and Geo-Information Science
基金
国家自然科学基金青年科学基金项目“基于主被动微波遥感技术的活动层冻融参量季节性变化规律研究”(41801277)
河北省高等学校科学技术研究项目——自然科学类青年项目“基于复杂地表综合数据库的地表冻融状态遥感监测算法研究”(QN2018072)。
关键词
被动微波遥感
地表冻融判别
验证
多层土壤温度
passive microwave remote sensing
discrimination of surface freeze-thaw
verification
multi-layer soil temperature