Normality analysis as a radio frequency interference detection

Radio-frequency interference (RFI) present in microwave radiometry measurements leads to erroneous radiometnc results. RFI sources include spurious signals and harmonics from lower frequency bands, spread-spectrum signals overlapping the "protected" band of operation, or out-of-band emissions not properly rejected by the pre-detection filters due to its finite rejection. RFI addition to the radiometnc signal modifies the detected power and the estimated antenna temperature from which the geophysical parameters will be retrieved. In recent years, techniques to detect the presence of RFI m radiometnc measurements have been developed. They include time- and/or frequency-domain analyses, or statistical analysis of the received signal which, in the absence of RFI, must be a zero-mean Gaussian process. The motivation of this paper is the study of a set of normality tests applied to the received signal which will be a combination of a thermal noise signal jointly with a set of RFI signals. In addition, performance of the different normality tests will be compared with the Kurtosis performance as a function of some parameters of the interfering signal to obtain the best solution in each case. A description of every normality test is presented.