Application Of AR Model Spectral Estimation In Improving Spectral Resolution

The aim of this study is to analyze the interference signal by AR model spectrum,so as to study the method of improving the resolution of the spectrum.Photoelectric detection has been playing an increasingly important role in the field of measurement.The spectrometer is an extremely photoelectric detection instrument is widely used,included CCD grating spectrometer and Fourier transform spectrometer(FTS),The traditional Fourier transform spectrometer has the characteristics of high accuracy,high sensitivity and high resolution.Meanwhile,because of the high efficiency of the fast Fourier transform(FFT)algorithm in calculating the discrete Fourier transform,The Fourier transform spectrometer also has the characteristics of high efficiency and real time.It has developed rapidly over the past decade.For the space modulation Fourier spectrometer,the data length is limited by the number of CCD pixels.And the frequency resolution is inversely proportional to the actual length of the data,so the resolution obtained by the usual Fourier transform is limited by the length of the data,except the method of changing the hardware by changing the number of CCD pixels and changing the cell size,there is another way that using the modern spectral estimation method,create a model for the data,extrapolated,so as to expand the data length,improve the resolution.In this paper,the Burg algorithm is used to calculate the power spectrum of the auto-regressive model of the data obtained by the space modulation Fourier spectrometer.The results obtained by this method have the characteristics of high computational resolution in the case of the appropriate AR model selection order,and still have some frequency resolution ability when the spatial frequency of the data is limited.Experiment results shows that the order of Burg algorithm effects frequency resolution and although spectral resolution can not be improved by using zero fill before FFT,But it obtains a result whose stability is similar to the result using Burg algorithm.