Monitoring Bare Soil Freeze-Thaw Process Using GPS-Interferometric Reflectometry: Simulation and Validation

doi:10.3390/rs10010014

	Monitoring Bare Soil Freeze-Thaw Process Using GPS-Interferometric Reflectometry: Simulation and Validation
	Wu, Xuerui 1,2; Jin, Shuanggen 1; Chang, Liang 3,4
刊名	REMOTE SENSING
	2018
卷号	10 期号:1 页码:18
关键词	GPS-IR multipath permittivity soil freeze-thaw process
ISSN号	2072-4292
DOI	10.3390/rs10010014
通讯作者	Wu, Xuerui(xrwu@shao.ac.cn)
英文摘要	Frozen soil and permafrost affect ecosystem diversity and productivity as well as global energy and water cycles. Although some space-based Radar techniques or ground-based sensors can monitor frozen soil and permafrost variations, there are some shortcomings and challenges. For the first time, we use GPS-Interferometric Reflectometry (GPS-IR) to monitor and investigate the bare soil freeze-thaw process as a new remote sensing tool. The mixed-texture permittivity models are employed to calculate the frozen and thawed soil permittivities. When the soil freeze/thaw process occurs, there is an abrupt change in the soil permittivity, which will result in soil scattering variations. The corresponding theoretical simulation results from the forward GPS multipath simulator show variations of GPS multipath observables. As for the in-situ measurements, virtual bistatic radar is employed to simplify the analysis. Within the GPS-IR spatial resolution, one SNOTEL site (ID 958) and one corresponding PBO (plate boundary observatory) GPS site (AB33) are used for analysis. In 2011, two representative days (frozen soil on Doy of Year (DOY) 318 and thawed soil on DOY 322) show the SNR changes of phase and amplitude. The GPS site and the corresponding SNOTEL site in four different years are analyzed for comparisons. When the soil freeze/thaw process occurred and no confounding snow depth and soil moisture effects existed, it exhibited a good absolute correlation (\|R\| = 0.72 in 2009, \|R\| = 0.902 in 2012, \|R\| = 0.646 in 2013, and \|R\| = 0.7017 in 2014) with the average detrended SNR data. Our theoretical simulation and experimental results demonstrate that GPS-IR has potential for monitoring the bare soil temperature during the soil freeze-thaw process, while more test works should be done in the future. GNSS-R polarimetry is also discussed as an option for detection. More retrieval work about elevation and polarization combinations are the focus of future development.
WOS关键词	DIELECTRIC-CONSTANT ; REFLECTED SIGNALS ; BISTATIC RADAR ; UNITED-STATES ; SNOW DEPTH ; SURFACE ; PARAMETERS ; SCATTERING ; MULTIPATH ; OCEAN
WOS研究方向	Remote Sensing
语种	英语
出版者	MDPI AG
WOS记录号	WOS:000424092300013
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/22193]
专题	中国科学院紫金山天文台
通讯作者	Wu, Xuerui
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Chinese Acad Sci, Key Lab Planetary Sci, Shanghai 200030, Peoples R China 3.Shanghai Ocean Univ, Coll Marine Sci, Shanghai 201306, Peoples R China 4.Collaborat Innovat Ctr Distant Water Fisheries, Shanghai 201306, Peoples R China
推荐引用方式 GB/T 7714	Wu, Xuerui,Jin, Shuanggen,Chang, Liang. Monitoring Bare Soil Freeze-Thaw Process Using GPS-Interferometric Reflectometry: Simulation and Validation[J]. REMOTE SENSING,2018,10(1):18.
APA	Wu, Xuerui,Jin, Shuanggen,&Chang, Liang.(2018).Monitoring Bare Soil Freeze-Thaw Process Using GPS-Interferometric Reflectometry: Simulation and Validation.REMOTE SENSING,10(1),18.
MLA	Wu, Xuerui,et al."Monitoring Bare Soil Freeze-Thaw Process Using GPS-Interferometric Reflectometry: Simulation and Validation".REMOTE SENSING 10.1(2018):18.