Radiometer Digital Radio Frequency Interference Detection System Research

Microwave radiometer is widely used in many fields, however, radio frequency interference (RFI) from a large number of radio equipment deteriorates the accuracy of microwave radiometer measurement seriously. This paper takes RFI detector of microwave radiometer as the object of study, describes the algorithm of the RFI detection and implementation of the devices in detail.First of all, the paper introduces the basic principles of the kurtosis-based algorithm, bulids the signal models and analyzes the false alarm rate and the detection rate of the algorithm. The recognition of RFI with different duty cycle is narrated in this article. In addition, it not only analyzes the performance improvement in kurtosis-based algorithm with sixth-order moment, but also introduces the energy detection algorithm and the Shapiro-Wilk test and then compares all algorithms mentioned above comprehensively.Secondly, it designs the digital RFI detection system for the microwave radiometer which includes analog band-pass filter, Analog-to-Digital converter, digital signal processing module, SDRAM control module for data writing and reading, universal serial bus for data transmission module and so on. It realizes the kurtosis-based algorithm with hardware description language and presents a simplified calculation of the kurtosis for RFI detection. In addition, this paper analyzes the effects of non-ideal digital sampling on the kurtosis calculations.Finally, this paper presents a radiometer RFI detection method with channelized structure which could improve the sensitivity of RFI detection. It realizes efficient channelized structure module and simulates with Matlab.The simulation results demonstrate that this structure could obtain good performances for radiometer RFI detection. This paper also realizes the efficient channelized structure module for RFI detection with the hardware description language.