摘要
由于传统的快速傅里叶变换(FFT)只适用于均匀采样的情况,对非均匀采样的干涉数据直接进行FFT会导致反演光谱的失真。针对该问题,国外的很多学者对非均匀快速傅里叶变换(NUFFT)方法进行了研究,并形成了比较成熟的理论。将NUFFT方法应用到干涉数据的光谱反演中,对不同采样频率和不同非均匀程度下的光谱反演精度进行了分析仿真,可以看出,在部分欠采样情况下,采样频率是影响光谱反演精度的主要因素;在过采样情况下,光程差的非均匀采样程度是影响反演精度的主要因素。实际应用中,需要综合考虑数据量、采样频率和光程差的非均匀采样程度来确定最终的参数。为了保证光谱反演的精度,获取的干涉数据中不存在部分欠采样是最基本的原则。
Traditional fast Fourier transform （FFT） is only useful in uniform sampled interferogram. For nonuniform sampled interferogram, the spectrum recovered by FFT is often distorted when the aliasing is neglected. To solve the problem, nonuniform fast Fourier transform （NUFFT） method is proposed and some mature theories are formed. The NUFFT is applied to the spectrum recovery of interferogram, and the interferogram at different sampling frequency and different degree of nonuniform optical path difference （OPD） is analyzed and simulated. The results indicate that sampling frequency is the main factor that affect the recovery precision for undersampled interferogram condition, while the nonuniform degree of OPD is more affective for oversampled interferogram condition. In the application, data quantity, sampling frequency and the nonuniform degree of OPD must be considered comprehensively to acquire the final design parameter. To ensure the recovery precision, avoiding the undersampling of gotten interferogram is the basic criteria.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2011年第12期84-88,共5页
Acta Optica Sinica
基金
国家973计划(2009CB724005)
国家自然科学基金(40805013)资助课题
关键词
光谱成像
干涉数据
光程差
非均匀采样
光谱反演
imaging spectroscopy interferogram optical path difference nonuniform sampling spectrum recovery
