Research And Implementation Of Broadband And High Resolution Spectrum Acquisition And Processing Technology

Spectral analysis technology plays an increasingly important role in qualitative analysis of metallurgical engineering,industrial detection,environmental monitoring,aerospace and other fields.However,because of the wide application of spectral analysis technology,high instrument function such as spectrum resolution,measurement speed and other functions of spectral analysis instruments are required.Because the resolution of current broad-band spectrometers is low,a technique base on broad-band high-resolution spectral acquisition and data processing has been studied in this paper.Follows are the main contents.Firstly,research and model of asymmetric Czerny-Turner optical system were made by using software of Zemax to simulation and analysis base on grating-related theories.Secondly,in order to obtain spectrum efficiency,a FPGA was used to perform control and data processing core.The acquisition,storage,processing,display of spectrum were achieved by using line array CCD which controlled by driver control program of FPGA.Thirdly,in order to reduce the noise and improve the signal-to-noise ratio of the spectral data,a hybrid noise reduction algorithm based on wavelet threshold is proposed.Both Gaussian white noise and impulse noise were reduced by adding median filtering to the approximation and detail coefficients after wavelet decomposition.The result of simulation shows the noise of the spectrum was effectively reduced and the signal-to-noise ratio of the spectrum was improved by using the algorithm.Finally,the system platform was built based on the designed asymmetric Czerny-Turner optical structure and acquisition and processing system of spectrum.The collected spectra were calibrated and analysis by using a monochromator.The experimental result shows that the central wavelength resolution of spectra achieved 0.632 nm with spectral coverage from300 nm to 830 nm.