Research On RFI Mitigation Method Based On Correlation Of Visibility

By cross correlations of the signals collected by any two antennas,Synthetic aperture technology obtains samples data of the visibility function.By conversion model between visibility function and brightness temperature,this technology achieves brightness temperature observation.It has been a growing trend in the domain of microwave radiation on-board detection.However,this technology isn't perfect,the radio frequency interference(RFI)has become the key factor of placing retriction on synthetic aperture remote sensing.For this reason,researchers develop works on RFI mitigation of synthetic aperture.On the basis of above content,an RFI mitigation method based on visibility correlation function is proposed in this article.The main contents are as follows:(1)Put emphasis on RFI mitigation for synthetic aperture imaging,introduce RFI mitigation research works at home and abroad;(2)Introduce the theory of the interferometer--synthetic aperture elementary unit,and then derive conversion model between visibility function and brightness temperature.Introduce inversion methods under this model.After provide readers the whole view of synthetic aperture imaging,briefly describe how the synthetic aperture imaging suffer from RFI;(3)The visibility characteristics induced by RFI and the one induced by natural scene are described.Then innovatively get the RFI model on visibility domain using these characteristics,and innovatively obtain model parameters by means of visibility correlation.Mitigate RFI using the known model;(4)Verify correctness of RFI model on visibility domain,the visibility characteristics induced by RFI and by natural scene using Soil Moisture and Ocean Salinity(SMOS)satellite data;(5)Use simulation experiments and SMOS satellite data to confirm validity of the RFI mitigation method proposed by this article.At the same time,compare this method with other RFI mitigation methods.It is evident that the RFI mitigation method proposed by this article has better performance for the air-ground RFI.