Research On Characteristics Of Synthetic Aperture Antenna Array And Design Of Image Inversion Algorithm

With the improvement of basic theories and the continuous development of various technologies,synthetic aperture radiometer has been applied in more and more fields,and is currently widely used in passive detection,remotes sensing imaging and many other aspects.The visibility function obtained by the synthetic aperture radiometer can be used to obtain the brightness temperature distribution of the imaging scene and the target through a certain algorithm.The antenna array optimization design and image inversion algorithm of SAR is an important part of the imaging performance improvement of SAR.In this thesis,the corresponding researches on the characteristics of the antenna array,the research on the optimization algorithm of the antenna array,and the research on the image inversion algorithm are carried out.The details are as follows:（1）The characteristics of the synthetic aperture radiometer antenna array are studied.The advantages of low redundancy array and high reliability array in image inversion are verified by simulation;the antenna error model is studied,and the influence of error on image inversion is verified by simulation.On this basis,the research puts forward the feasible technical ideas for the optimal design of the antenna array and the research on the image inversion algorithm.（2）The antenna array optimization algorithm based on particle swarm optimization is studied.Aiming at the problem that the binary particle swarm algorithm is easy to fall into a stagnant state,the "catfish particle" is introduced to improve the activity of the particle swarm in order to reduce the number of iterations.The simulation results show that the algorithm can effectively reduce the number of iterations and provide more feasible antenna arrangements for the actual system design.（3）The optimization problem of the array aiming at low redundancy and high reliability is studied,and a two-dimensional planar array is obtained.Through simulation,it is found that the constructed two-dimensional array（compared to the typical array）has the advantages of larger sampling area and more sampling points under the condition of the same number of array elements,which can effectively reduce the redundancy of the system.Using the above array to perform image inversion simulation under the condition of error,the experimental results show that the two-dimensional sparse array can effectively reduce the error,thereby effectively improving the imaging accuracy of image inversion.（4）The image inversion algorithm based on Tikhonov regularization is studied.Aiming at the problem that the algorithm corrects all singular values indiscriminately,which affects the imaging accuracy,the filter factor is divided into two parts by the threshold threshold,and the singular values of different sizes are corrected differently,temperature for further correction and simulation experiments.The experimental results show that the improved algorithm can effectively improve the inversion imaging accuracy in the presence of noise.