Research On Radio Frequency Interference Detection Method Of Radiometer Based On Joint Domain

The radiometer is widely used in the passive remote sensing field, but radio frequency interference (RFI) caused by the increasingly complex electromagnetic environment has an important influence on the measuring accuracy of the radiometer. The research of RFI detection has important significance. In view of the existing RFI detection methods are only independent of time domain or frequency domain, ignoring the time-frequency domain characteristics of the signal, this paper proposes a RFI detection algorithm based on joint domain.Firstly, the paper analyzes the mechanism of RFI. On the basis of introducing the principle of the radiometer and the system model of the full power radiometer, the paper makes a quantitative analysis of the Radiometer signal passing through the full power radiometer in the presence of RFI, then obtains the contribution relation of RFI to the output brightness temperature of radiometer.Secondly, based on the analysis of the Power-Law detection algorithm, a Power-Law RFI detection algorithm based on time frequency domain is proposed. The paper analyzes the exponential value and the STFT window function to obtain the parameter optimal solution. Performance of the algorithm is analyzed under different SNR and duty cycle of RFI. Building a Radiometer RFI detection simulation system verifies the correctness of the time-frequency Power-Law detection algorithm.Finally, on the basis of kurtosis detection, a RFI detection algorithm based on wavelet statistical domain is proposed. The selection of wavelet basis is discussed to obtain that the greater the number of Db wavelet, the better the frequency band is divided. Performance of the algorithm is analyzed under different SNR and duty cycle of RFI and the relationship between detection probability and SNR is obtained. The simulation experiment system of RFI detection is used to verify the algorithm based on wavelet statistical region detection.