Research On Phase Retrieval Holography Method For Antenna Surface Measurement

The large reflector antenna is one of the important equipment for the deep space exploration in the future and the forward radio astronomy observation.The surface accuracy of antenna is an important factor influencing on efficiency and the performance of antenna.Surface accuracy is not only effected by panel processing and installation but also effected by gravity,temperature and wind load.These factors will lead to a lower gain,changing antenna pattern and so on.Therefore the surface accuracy becomes an important index for evaluating the performance of large reflector antenna.Aiming at the measurement method for surface accuracy,we have made a series of research work.First of all,according to surface detection technology on the development trend at home and abroad,the author study on surface measurement method based on phase retrieval holography.Based on the detailed derivation of phase retrieval holography method,many phase retrieval algorithms are analyzed and the simulation code of the Misell algorithm is written.Secondly,the far-field model of Misell algorithm is established,and the preset surface deformation is retrieved using far-field data,which are generated by the far field simulation model.We analyse retrieval accuracy and errors of algorithm by simulating the Misell algorithm.The simulation provides references to configure parameters of measurement in a practical application.Finally,on the basis of simulating the Misell phase retrieval algorithm,we study the method of phase retrieval holography based on the active deformation of the active reflector surface.This method by means of the features of fast,accurate and convenient in active reflector,we can get the far field amplitude through adjusting the active surface,and thus can detect the surface error.By building the models of numerical simulation based on the Gaussian function and Zernike polynomials,retrieval error of arbitrary surface deformation is calculated and retrieval results of arbitrary surface deformation in a variety of active surface deformation also be studied.It is indicated that this method can stably and accurately detect surface deformation,and can also improve the efficiency of radio telescope observations effectively.