On the detection of RFI using the complex signal kurtosis in microwave radiometry

Radio-frequency interference (RFI) is a threat to the utility of radiometric measurements by spaceborne microwave radiometers since it corrupts natural thermal emission that must be remotely sensed by the radiometer. Use of these measurements containing undetected RFI results in erroneous geophysical parameter retrievals [1]. Various test-statistics such as the kurtosis are currently used to detect RFI. These are based on measurements of non-Gaussianity of the probability density function (pdf ) of the received radiometer signal [2,3]. Though the kurtosis was shown to be the best test-statistic for detecting a wide variety of RFI signal types, to date, only the kurtosis of real-valued signals has been applied to the problem of RFI detection. This paper investigates the use of the complex signal kurtosis in full-polarimetric radiometers for RFI detection.