Knowledge Resource Center for Ecological Environment in Arid Area
MONITORING OF SOIL MOISTURE DYNAMICS IN THE SEMI-ARID TROPICS BY MEANS OF ALOS-2/PALSAR-2 DUAL-POLARIZATION SCANSAR DATA | |
Koyama, Christian N.1; Watanabe, Manabu1; Shimada, Masanobu1,2 | |
通讯作者 | Koyama, Christian N. |
会议名称 | 38th IEEE International Geoscience and Remote Sensing Symposium (IGARSS) |
会议日期 | JUL 22-27, 2018 |
会议地点 | Valencia, SPAIN |
英文摘要 | In the dry tropical forest and semi-arid savanna information about the soil moisture dynamics and distribution are vital to better understand and mitigate damages caused by drought. To estimate the soil moisture over large areas from 50-m resolution ALOS-2 ScanSAR data, we adopt dual-polarization L-band algorithms originally developed for high resolution ALOS data. Based on the partial-polarimetric eigenvector decomposition, the scattering entropy and alpha angles are employed to correct for the above ground vegetation effects. The large incidence angle variation along the 350-km ScanSAR swath requires the use of an incidence angle correction factor. However, due to the relative poor data quality of the ScanSAR products suffering from scalloping and near-range/far-range striping along the subswathes, we observe lower accuracies than Stripmap mode. While in the dry season soil moisture retrieval in the open forest is well possible, in the rainy season the entropy exceeds the validity range due to the larger amounts of canopy biomass resulting in unreliable soil moisture estimates. Savanna vegetation allows a biomass-corrected soil moisture estimation throughout the whole year. Due to the lack of distributed in-situ data, we use coarse scale SMOS and SMAP soil moisture data to validate the accuracy of dual-polarization ScanSAR soil moisture estimates. Comparisons between the kilometer-scale radiometer derived soil moisture estimates and 50-m ALOS-2 results show a good agreement in the dry season with RMSEs smaller 5 Vol.-%, while in the rainy season the RMSEs can be as high as 15 Vol.-%. |
英文关键词 | Dry tropical forest JJ-FAST Lband soil moisture polarimetry |
来源出版物 | IGARSS 2018 - 2018 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM |
ISSN | 2153-6996 |
出版年 | 2018 |
页码 | 5513-5516 |
EISBN | 978-1-5386-7150-4 |
出版者 | IEEE |
类型 | Proceedings Paper |
语种 | 英语 |
国家 | Japan |
收录类别 | CPCI-S |
WOS记录号 | WOS:000451039805092 |
WOS关键词 | RETRIEVAL |
WOS类目 | Engineering, Electrical & Electronic ; Geosciences, Multidisciplinary ; Remote Sensing |
WOS研究方向 | Engineering ; Geology ; Remote Sensing |
资源类型 | 会议论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/307255 |
作者单位 | 1.TDU, Sch Sci & Engn, Hatoyama, Saitama 3500394, Japan; 2.EORC, JAXA, 2-1-1 Sengen, Tsukuba, Ibaraki 3058505, Japan |
推荐引用方式 GB/T 7714 | Koyama, Christian N.,Watanabe, Manabu,Shimada, Masanobu. MONITORING OF SOIL MOISTURE DYNAMICS IN THE SEMI-ARID TROPICS BY MEANS OF ALOS-2/PALSAR-2 DUAL-POLARIZATION SCANSAR DATA[C]:IEEE,2018:5513-5516. |
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