The inversion method study of sub-canopy soil moisture estimation using repeat pass SIR-C PolInSAR data
重复轨道SIR-C极化干涉SAR数据植被覆盖区土壤水分反演研究

Noise estimation plays significant role in payload assessment, image processing and data application. In this paper, considering characteristics of Beijing-1 small satellite,the the image-based noise estimation methods with their applicabilityy are appraised in theories considering characteristics of Beijing-1 small satellite and , their performances are compared and analyzed through experiments,. and Tthe parameters and model optimization are also also discussed for better assessment of noise. for accurate estimation of the noise. Synthetic With comprehensive analysis of noise estimation results from different land cover types, the Beijing-1 small satellite noise estimation of Beijing-1 small satellite is evaluated with its standard deviation.conducted with carefully selected images and from different land cover types. Comparison of the noise estimation from images acquired in 2008 and the in-orbit test right after launch in 2005 shows that noise level of the Beijing-1 small satellite does not change, the satellite has well-kept performance even after 3 years of operation.