Research On Two Dimensional Spectral Data Processing Method

In recent years,the astronomical observation technology is developing rapidly.The great improvement of astronomy in China depends on the completion of LAMOST.The full name of LAMOST is Large Sky Area Multi-Object Fiber Spectroscopy Telescope,also known as the Guo Shoujing telescope.LAMOST provides excellent data sources and research platform for researchers.This thesis introduces the observation model of LAMOST.About the data processing system,the principle and function of each subsystem are explained.The data types and characteristics of observed spectra are illustrated.The issues related to two-dimensional spectral data processing are collected and studied.In this thesis,the focus work is on the deformation correction of two-dimensional spectrum.Several feasible algorithms are proposed to restore the deformation,and the accuracy of these algorithms is verified by experiments.The main works and contributions of this thesis are described as follows:1.Based on the characteristics of the two-dimensional optical fiber spectral data,the problem of bending deformation is noticed.This thesis analyzes the causes of the deformation and explains the necessity of post-processing.Based on the characteristics of spectral deformation,we put forward the normal mapping correction algorithm,the finite element analysis(FEA)algorithm and image pincushion correction algorithm.2.The basic steps of normal mapping correction algorithm are introduced.We studied this method from theoretical and experimental aspects to prove its feasibility.The experimental results show that the two dimensional spectra are well corrected.3.Based on the load deformation of beam structure in structural mechanics,combined with the bending characteristics of LAMOST spectra,the finite element method is proposed to correct deformation.Select suitable data as the units and nodes to build the finite element model,and analyze the load on the fiber central curve,then the deformation can be restored by the reaction force.Experimental results demonstrate the effectiveness of the method.