標題: On temporal-spatial distribution of backscatter coefficients over China determined by TOPEX/Poseidon mission
作者: Guo JinYun
Yang Lei
Liu Xin
Hwang, CheinWay
Yang Hong
土木工程學系
Department of Civil Engineering
關鍵字: backscatter coefficient;satellite altimetry;TOPEX/Poseidon;land surface;SRTM
公開日期: 1-Dec-2012
摘要: This paper deals with the backscatter coefficients known as sigma0 at Ku band and C band based on the GDR-M (Merged Geophysical Data Record) of TOPEX/Poseidon (T/P) through Jan. 1993 to Dec. 2004 over land surface of China. After smoothing and interpolating the backscatter coefficients for both bands, we achieve the 5'x5' grid data and the time series of backscatter coefficients in 12 years. The spatial distribution of sigma0 over typical areas (wetland, desert, mountainous area, agriculture base, etc.) of Chinese territory is analyzed and discussed. The fast Fourier transformation (FFT) is used to detect the cycles of seasonal variations of sigma0 time series and gives that the annual period is the major cycle. Meanwhile a semiannual period is also found in some places. We use the least squares method on both periods and find that the amplitude of annual period is obviously greater than that of semi-annual period. The relationship among the anomalousness of time series, variations of environment and climate change, and the serious natural calamity (flood, drought) is also discussed. Data of topography slope extracted from SRTM are used to do correlation analysis with the backscatter coefficients in parts of China to quantify the impact of slope on backscatter coefficients in Ku and C bands, and the results show that they all have a negative correlation but the magnitudes are different in different places with different coverages. Such as the area of Liaoning and Jilin has the maximum correlation -0.56, the Taklimakan Desert has the minimum correlation -0.11, and the other places commonly have correlations in (-0.3, -0.5).
URI: http://dx.doi.org/10.1007/s11430-012-4524-y
http://hdl.handle.net/11536/20852
ISSN: 1674-7313
DOI: 10.1007/s11430-012-4524-y
期刊: SCIENCE CHINA-EARTH SCIENCES
Volume: 55
Issue: 12
起始頁: 2068
結束頁: 2083
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