CAJ | 학술논문

针对低信噪比条件下光谱抽取精度较低的问题，对输入二维光谱图像进行预处理，提出了一种在Wigner时频域加权滤波的方法进行光纤光谱信号降噪，改善低信噪比的光谱数据质量。针对传统低通滤波不能滤除通带内混叠噪声的缺陷，采用Wigner变换获取光谱信号高集中度的时频分布。先构建带通滤波器滤除较分散的明显噪声分量，再针对通带部分设计加权滤波器，根据信号的先验信噪比进行非线性处理，最后利用Wigner变换的边缘特性重构有效信号。实验部分采用大天区面积多目标光纤光谱望远镜（ the Large Sky Area Multi-Object Fiber Spectroscopic Telescope， LAMOST）系统的仿真和实测数据验证算法的有效性。
침대저신조비조건하광보추취정도교저적문제，대수입이유광보도상진행예처리，제출료일충재Wigner시빈역가권려파적방법진행광섬광보신호강조，개선저신조비적광보수거질량。침대전통저통려파불능려제통대내혼첩조성적결함，채용Wigner변환획취광보신호고집중도적시빈분포。선구건대통려파기려제교분산적명현조성분량，재침대통대부분설계가권려파기，근거신호적선험신조비진행비선성처리，최후이용Wigner변환적변연특성중구유효신호。실험부분채용대천구면적다목표광섬광보망원경（ the Large Sky Area Multi-Object Fiber Spectroscopic Telescope， LAMOST）계통적방진화실측수거험증산법적유효성。
In observations with the LAMOST ( the Large Sky Area Multi-Object Fiber Spectroscopy Telescope) observed two-dimensional spectral images of low signal-to-noise ratios (SNR) need to be preprocessed to ensure sufficient accuracies of the spectra extracted from the images.In this paper, we propose an improved method for denoising spectral images observed through the LAMOST fiber optics.Our method is based on weighted filtering in the frequency domain of the Wigner transformation.Considering that a conventional low-bandpass filter cannot filter out aliasing noise, we design our method to use the Wigner transformation to obtain spectral profiles of fluxes highly concentrated in the frequency domain.The method first removes appreciable dispersed noise components by a specially constructed bandpass filter, then applies a weighted filter to nonlinearly process the signals in the bandpass based on a priori SNR data.The method finally uses the boundary features of the Wigner transformation to effectively reconstruct signals.We present experiments of applying the improved method to simulated and observed LAMOST data.Our experiments demonstrate the effectiveness of the improved method.