基于AMSR-2数据的多种射频干扰识别方法的比较

由于射频干扰（radio-frequency interference,RFI）对星载微波遥感的影响日益严重,为了比较各种识别方法的适用性,基于先进微波扫描辐射计（advanced microwave scanning radiometer 2,AMSR-2）2015年冬季和夏季的观测亮度温度,分别采用谱差法、多通道回归分析法、双主成分分析法和比值法,对欧洲陆地区域和海洋区域的10.65 GHz和7.3 GHz频率干扰进行识别和分析,并对比几种方法的月综合结果.结果表明,冬季时谱差法在陆地上受积雪散射的影响,会将积雪下垫面误判为RFI污染;多通道回归分析法和双主成分分析法识别出的结果类似,无论陆地和洋面还是冬季和夏季均可有效使用;当10.65 GHz和7.3 GHz波段观测同时存在RFI时,比值法将不能识别出10.65 GHz的RFI信号,并且比值法会将海陆边界及附近视场的观测误判为RFI信号.多通道回归分析法和双主成分分析法的适用范围较为广泛,而谱差法和比值法各有弊端.

A comparison of radio-frequency interference detection based on AMSR-2 data

The influence of radio-frequency interference on microwave remote sensing has become increasingly serious. In order to better use the observed data, it is necessary to correctly identify and remove radio-frequency interference(RFI) contamination. To find out the applicability of various methods, the spectral difference method, multi-channel regression analysis method, double principal component analysis (DPCA) method and ratio method are used respectively to recognize RFI signals in the Advanced Microwave Scanning Radiometer 2 (AMSR-2) observations at 10.65 GHz and 7.3 GHz channels and the monthly results of above methods are compared. Research shows, the spectral difference method is influenced by the scattering of snow and misjudged the underlying surface of snow as RFI pollution in land during winter. Meanwhile, both the multi-channel regression analysis method and the DPCA method have stronger applicability and are equally effective in both land and ocean or winter and summer. When the RFI exists simultaneously in 7.3 GHz and 10.65 GHz channel observations, the ratio method will not recognize the RFI signal of the 10.65 GHz. On the ocean surface, the ratio method will misjudge the observation of the sea-land boundary and nearby field of view into RFI. In short, both the multi-channel regression analysis method and the DPCA method have a wide range of applications, but the spectral difference method and the ratio method have their own drawbacks.