Research On Error Correction Of Delay-related Synthetic Aperture Imaging Radiometers

The synthetic aperture radiometer sacrifices the equipment imaging structure and processing complexity,and has obtained the advantages of small size,high resolution,and real-time imaging speed,and is widely used in modern earth science.Therefore,in order to effectively reduce the complexity of the system,on the basis of proposing a comprehensive aperture radiation measurement method based on delay correlation,this paper conducts an imaging error correction study on it.First,based on the incoherent characteristics of microwave radiation signals,the basic binary correlator of complex correlation in the delay-related integrated aperture is derived,and on this basis,the basic principle of delay-related correlation is derived.From the structure,I analyzed the error types in the system based on the time-dependent correlation aperture.Secondly,based on the situation that the actual system imperfections will bring errors,this paper builds a delay-related integrated aperture system from the simulation level.To study the errors that have a great impact on the performance of the bright temperature imaging reconstruction process: the specific effects of aliasing errors and mutual coupling errors on the imaging image.Provide a reference for subsequent experiments in the digital domain.Finally,this paper completes the imaging experiment based on the actual detection data,builds a delay-related system on the platform of the 51 GHz synthetic aperture radiometer system,arranges the digital signal sequence of the array channel after sampling to simulate the delay line,and constructs the corresponding Data related to the delay.Starting from the characteristics of the autocorrelation function of the channel multiplexed data,the theoretical delay correlation imaging is used as the criterion,and the following research is done:1)For aliasing errors,a non-aliasing correction method is proposed to adjust the non-aliasing delay time when processing data.2)For the mutual coupling error,the importance of the correlation degree in the delay correlation is determined in the scenario where the mutual coupling error has a large influence.For the weakly correlated spreading source signals,the non-aliasing correctionmethod and the external scene cancellation method are used for joint correction.For the problem of excessive side lobes in imaging,a method of optimizing the visibility function with a windowing function is proposed to enhance its correlation.3)For the simulation delay system error,a method based on non-diagonal element difference auxiliary source correction is used to optimize and correct conventional data.The experimental results show that the correction method can accurately obtain the target azimuth information and improve the imaging quality.