Spectral Calibration Of The High Spatial Resolution And High Hyper-spectral CO2Detector

Greenhouse effechas seriously affected activities and existence of human. So, The space developed countries in Europe and America are being actively engaged in the research of the greenhouse gas remote sensing instrument. As a large developing country, China also must develop her own atmospheric greenhouse gas remote sensing system to monitor the world greenhouse gas emissions of both the national and the others, to improve the right to speak of our country in the carbon politics and carbon trading negotiations. In the above context,The National863Program support the implementation of the major projects-"The Global Carbon Dioxide Monitoring Scientific Experimental Satellite Demonstration" and the CIOMP is responsible the development work of the" carbon satellite" payload-the hyper-spectral CO2detector with high spatial resolution (herein after referred to as "CO2detector")。CO2detector is based on the principle of atmospheric gas molecules absorbing pools, and uses the means of optical remote sensing technology, with precise inversion of atmospheric gas concentrations by Absorption spectroscopy of some gas molecules. Spectral calibration of the instrument is the basis of the fine data quantify applied. With the spectral resolution must reach the index of0.04nm, and the Spectral calibration accuracy have to reach Δλ/10(Δλ for the spectral bandwidth of spectral calibration). Such high calibration accuracy for laboratory spectral calibration is a calibration accuracy have to reach Δλ/10(Δλ for the spectral bandwidth of spectral calibration). Such high calibration accuracy for laboratory spectral calibration is a great challenge.On the basis of the summary of the advantages and disadvantages of the high spectral resolution laboratory spectral calibration techniques and method used, the text has supported Spectral calibration methods and steps for CO2detector. The instrument spectral characteristics are expected to be obtained by laboratory spectral calibration, containing the center wavelength of each spectral channel position and the spectral characteristics of each channels (half-width, or the ILS).First, we introduces "mono-chromator" spectral calibration system to calibrate the bandwidth. After then the "Gas absorption cell" spectral calibration system and HITRAN database are used to further calibrate the center wavelength position of each channels.The text analyze of the experimental data on the spectral calibration, at the same time assess the uncertainty in the experimental process. Data analysis showed:The half-width of instrument is about0.05nm. The center wavelength position accuracy of each channels by gas absorption method, can reach about0.013nm. Through spectral calibration experiment for the demonstrator-0.76μm band, The conclusion can be gained:The laboratory spectral calibration program combination the method of mono-chromator scanning and the method of gas absorption, can greatly improve the instrument spectral calibration standard.On the basis of Analyzing the uncertainty and the sources of error in spectral calibration test results for the demonstrator-0.76μm band, we expect to correct the spectral experimental procedure and data processing algorithms. So that, the accuracy of spectral calibration will be improved further, and provide reliable data and experimental basis for the follow-up spectral calibration work.