像元尺度土壤水分监测网络及其对L波段土壤水分产品的初步验证结果  

Pixel-scalesoil Moisture Monitoring Network and Its Preliminary Validation of L-band Soil Moisture Products

作　　者：白瑜 孟治国[1] 赵凯[2,3] 郑兴明[2,3] 姜涛[2,3] Bai Yu1,2 ,Meng Zhiguo1 ,Zhao Kai2,3 ,Zheng Xingming2,3 ,Jiang Tao2,3(1.Faculty of GeoExploration Science and Technology, Jilin University, Changchun 130026, China ;2.Northeast Institute of Geography and Agroecology ,Chinese Academy of Sciences, Changchun 130102,China ;3.Changchun Jingyuetan Remote Sensing Experiment Station, Chinese Academy of Sciences, Changchun 130102, China)

机构地区：[1]吉林大学地球探测科学与技术学院,吉林长春130026 [2]中国科学院东北地理与农业生态研究所,吉林长春130102 [3]中国科学院长春净月潭遥感试验站,吉林长春130102

出　　处：《遥感技术与应用》2018年第1期78-87,共10页Remote Sensing Technology and Application

基　　金：吉林省科技发展计划优秀青年人才基金项目(20170520078JH);科技基础性工作专项"测绘地物波谱本底数据库建设"(2014FY210800-4);中国科学院东北地理与农业生态研究所青年科学家小组项目"基于卫星星座观测体系的农业遥感信息服务示范系统关键技术研发"(DLSXZ1602)

摘　　要：土壤水分是作物生长、地—气水热交换及全球水循环过程中的关键变量,对于旱情监测、水文陆面过程及气候变化的研究具有重要的意义。被动微波遥感凭借对于土壤水分的敏感性已经成为监测土壤水分的主要手段。研究中针对吉林省农田下垫面,利用土壤水分传感器网络监测数据,开展了SMAP(Soil Moisture and Active and Passive)和SMOS(Soil Moisture and Ocean Salinity)被动微波土壤水分产品的真实性检验研究,得出了以下结论:(1)与实测数据相比较,SMOS L3(升降轨)和SMAP L3被动微波土壤水分产品存在低估现象,伴随降雨事件会出现高于实测土壤水分的情况;两种被动微波土壤水分产品的无偏均方根误差(unRMSE)都大于0.07m3/m3,但SMAP L3被动微波土壤水分产品数据的ubRMSE略低,为0.078m3/m3;(2)由于L波段的感应深度要浅于传感器的探测深度5cm,降雨后土壤表层的变干现象导致土壤水分的垂直不均匀性,这是SMOS和SMAP被动微波土壤水分产品低估土壤水分的原因之一;(3)SMOS与SMAP亮温分布范围对比结果表明:由于电磁射频干扰(RFI)的影响,RFI对于SMOS的影响更为严重,这或许是SMOS土壤水分产品的RMSE高于SMAP被动微波土壤水分产品的原因。Soil moisture is a key variable in the process of crop growth,ground-air water heat exchange and global water cycle, which plays an important role in drought monitoring, hydrological land surface processes and climate change. Passive microwave remote sensing has become the main means of monitoring soil moisture with the sensitivity to soil moisture. In this study, the authenticity test of SMAP（Soil Moisture and Active and Passive） and SMOS（Soil Moisture and Ocean Salinity）passive microwave soil moisture products using the soil moisture sensor network monitoring data carried out against the underlying surface of farmlands in Jilin Province was carried out.The following conclusions were obtained： （1）Compared with the in situ measured data,SMOS L3（ascending and descending overpasses） and SMAP L3 passive microwave soil moisture products generally underestimated the ground data, but With the occurrence of rainfall events, there will be the phenomenon which is the value of soil moisture products is higher than the in situ data; although the unbiased root mean square error （unRMSE） of the two soil moisture products was greater than 0.07 m^3/m^3, the unRMSE of SMAP passive microwave soil moisture product data which was 0.078 m^3/m^3 was slightly lower; （2）Since the depth of induction of the L-band is lighter than the depth of detection of the sensor（5cm） ,and the dryness of the soil surface after rainfall causes the vertical inhomogeneity of soil moisture,which is one of the reasons why SMOS and SMAP passive microwave soil moisture products underestimate soil moisture; （3）SMOS has a higher value than the range of SMAP brightness temperature,which may be caused by radio frequency interference （RFI）, which makes the error of soil moisture Retrieval and affects the validation accuracy.The comparison of bright temperature distribution of SMOS and SMAP shows that the effect of RFI on SMOS is more serious due to the influence of electromagnetic radio frequency interference （RFI）, which

关 键 词：土壤水分 微波遥感 SMAP SMOS 验证 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]