Preliminary calibration of GPS signals and its effects on soil moisture   estimation

doi:10.1007/s13351-013-0207-7

CORC > 北京大学 > 地球与空间科学学院

	Preliminary calibration of GPS signals and its effects on soil moisture estimation
	Wan Wei ; Li Huang ; Chen Xiuwan ; Luo Peng ; Wan Jiahuan
刊名	acta meteorologica sinica
	2013
关键词	GNSS-R soil moisture signal calibration bistatic radar SMEX02
DOI	10.1007/s13351-013-0207-7
英文摘要	In recent years, Global Navigation Satellite Systems Reflectometry (GNSS-R) is developed to estimate soil moisture content (SMC) as a new remote sensing tool. Signal error of Global Positioning System (GPS) bistatic radar is an important factor that affects the accuracy of SMC estimation. In this paper, two methods of GPS signal calibration involving both the direct and reflected signals are introduced, and a detailed explanation of the theoretical basis for such methods is given. An improved SMC estimation model utilizing calibrated GPS L-band signals is proposed, and the estimation accuracy is validated using the airborne GPS data from the Soil Moisture Experiment in 2002 (SMEX02). We choose 21 sites with soybean and corn in the Walnut Creek region of the US for validation. The sites are divided into three categories according to their vegetation cover: bare soil, mid-vegetation cover (Mid-Veg), and high-vegetation cover (High-Veg). The accuracy of SMC estimation is 11.17% for bare soil and 8.12% for Mid-Veg sites, much better than that of the traditional model. For High-Veg sites, the effect of signal attenuation due to vegetation cover is preliminarily taken into consideration and a linear model related to Normalized Difference Vegetation Indices (NDVI) is adopted to obtain a factor for rectifying the "over-calibration", and the error for High-Veg sites is finally reduced to 3.81%.; Meteorology & Atmospheric Sciences; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 1; ARTICLE; 2; 221-232; 27
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/155643]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Wan Wei,Li Huang,Chen Xiuwan,et al. Preliminary calibration of GPS signals and its effects on soil moisture estimation[J]. acta meteorologica sinica,2013.
APA	Wan Wei,Li Huang,Chen Xiuwan,Luo Peng,&Wan Jiahuan.(2013).Preliminary calibration of GPS signals and its effects on soil moisture estimation.acta meteorologica sinica.
MLA	Wan Wei,et al."Preliminary calibration of GPS signals and its effects on soil moisture estimation".acta meteorologica sinica (2013).