Research On The Key Technologies Of Synthetic Aperture Radiometers Based On Time-delay Correlation

The technology of synthetic aperture microwave radiometer is quite mature,it is widely used in the field of remote sensing,target detection and so on.Compared with the real aperture microwave radiometer,the synthetic aperture microwave radiometer uses a small antenna to replace the large antenna,which avoids the difficulty of the mechanical scanning.However,due to the problem of channel inconsistency in the large aperture radiometer,the number of channels and correlators is too high,which can lead to the distortion of the brightness temperature of the radiometer,especially in the application of spaceborne synthetic aperture radiometer.Moreover,the correction of error in spaceborne system becomes a difficult problem.The correlation operation takes a lot of time,so that the time of data processing is long and the efficiency is low,especially when the amount of data is large.In this context,the present work aims to propose a new microwave radiometric imaging system: the synthetic aperture radiometer based on time-delay correlation.The basic theory of the time-delay correlation system is analyzed and verified by simulation.First,this paper expounds the basic theory of synthetic aperture radiation imaging,and thus leads to the theory of synthetic aperture radiometer with time-delay correlation.The basic characteristics of electromagnetic radiation are analyzed,and the difference the visibility function between traditional synthetic aperture and the synthetic aperture radiometer with time-delay is compared.Then,the main error sources(antenna position error,delay line attenuation error,periodic signal interference error)of the time-delay synthetic aperture radiometer are analyzed.The mathematical models of these errors are analyzed.Finally,the simulation results are verified by practical equipment,and the simulation results are compared with the traditional methods.The results show that the method can realize the acquisition of target azimuth information,and the complexity of the synthetic aperture radiometer based on time-delay correlation is significantly lower than that of the conventional synthetic aperture radiometer.