Research On Gas Inversion Technology In Space Life Science

In the process of growth,a variety of gases,such as carbon dioxide,ethylene,ammonia and so on,can not only reflect the growth of organisms,but also affect the living quality of organisms.In the space life science experiment,the airtight,microgravity and strong radiation environment will change the composition and content of the gas produced by the organism.Through the analysis of the composition and content of these gases,it can better reveal the influence of the space environment on the organism,and can also present the abnormal situation in time,and make the experiment in time to make the experiment.Proceed smoothly.In order to meet the high precision measurement of gas component content in the space life science experiment,a set of multi component trace gas inversion algorithm in space life science experiment based on Fourier transform spectroscopy(FTIR)was designed.The main research content and research results are as follows:1)The standard spectra of different resolution are obtained.First,on the basis of HITRAN database,the mole absorption coefficient of ethylene molecules and carbon dioxide molecules is calculated and calculated.The calculation spectra of two kinds of gases are calculated according to Bill's law,and two kinds of gas are calculated and used to calculate the two kinds of gas.A standard spectrum at different resolution.2)In view of the problem of noise and baseline drift in the infrared spectra measured in life science experiments,spectral signals need to be pre processed before inversion.After analyzing the principles and advantages and disadvantages of various preprocessing methods,the spectral smoothing method is used to correct the spectral baseline,and the wavelet threshold filtering algorithm is used to denoise white noise,and a comprehensive denoising solution for multi component gas is proposed,and the wavelet transform of the measured spectrum of the life science experiment is realized.Soft threshold filtering algorithm and baseline correction algorithm.3)Comparing the principle and function of various inversion algorithms,the LM-PLS method is used to inverse the measured spectral data,and the concentration information of the gas to be measured is successfully obtained in the experiment.The experimental results show that the spectral denoising method of the integrated baseline correction algorithm and the wavelet soft threshold filtering algorithm can effectively avoid the error caused by the spectral noise to the gas concentration inversion,and improve the detection precision and the detection limit.In the actual measurement,the minimum detection limit of carbon dioxide gas is achieved under the laboratory condition with MB3000 infrared spectrometer combined with long distance gas pool to 1ppm,the error is less than 1ppm,the gas detection limit of ethylene is up to 10 ppm and the error is less than 2ppm,and the quantitative analysis of the gas component under the greenhouse bar is carried out.Experiments show that the inversion results of the algorithm can basically meet the technical specifications of space life science experiments.