| At present,China’s air pollution situation is serious,and the total emission of air pollutants remains high,among which the emission of chemical pollution gas accounts for a high proportion,causing great harm to the air environment and human health.Accurately monitoring the composition,concentration,and distribution of exhaust gases is a requirement for controlling such issues.Therefore,the monitoring technology of satellite-based remote sensing equipment is quickly developing in order to better monitor global and regional chemical pollution gases in real time.On April 16,2022,the Atmospheric Environment Monitoring Satellite(AEMS)will launch from the Taiyuan Satellite Launch Center with the Spaceborne Environment trace gas Monitoring Instrument-Ⅱ(EMI-Ⅱ).The device measures the process of polluting gas dispersion and transmission both locally and internationally.The instrument’s remote sensing data must first be calibrated in order to be quantified,and the simulation of the in-orbit vacuum environment for spectral and irradiance calibration that takes place prior to launch is crucial for determining how much attenuation the payload will experience after in-orbit operation.The instrument calibration test equipment is constructed utilizing the vacuum target chamber system,and its system composition and operating principle are also introduced in order to realize the consistent working environment on the ground and in space.This thesis focuses on the technique of ground-based vacuum spectroscopy and irradiance calibration of the instrument,and establishes the framework for its quantitative inversion.This thesis focuses on the technique of ground vacuum spectroscopy and irradiance calibration of the instrument,and establishes the framework for its quantitative inversion.The EMI-Ⅱ spectral calibration includes wavelength calibration and spectral response function measurement.Based on the grating spectroscopy method of EMI-Ⅱ,mercury-argon and neon lamps were selected as the calibration lamps,and the standard spectral line method was used for wavelength calibration.Pre-processing,peak-seeking processing,characteristic peak image element order-wavelength matching,linear regression analysis,and uncertainty analysis were used to obtain the spectral range,spectral calibration equation,and spectral resolution(all between 0.3nm and 0.5 nm)of the four channels of the instrument.The drift analysis was performed for the characteristic peaks of the same image element in atmospheric and vacuum modes,and the results showed that there was no significant change in the spectral resolution in the two modes of operation.For EMI-Ⅱ irradiance calibration,the concepts of spectral irradiance and spectral irradiance were introduced.According to the EMI-Ⅱ irradiance calibration scheme,the corresponding calibration device is established,and the integrating sphere method is used for irradiance calibration.150 W tungsten halogen lamp and 300 W xenon lamp are built into the integrating sphere as calibration lamps,and the output data of the instrument are processed to obtain the absolute radiation calibration coefficients,and the uncertainty of the calibration process is analyzed,and the results are better than 5%.Analysis of the central field-of-view data of the instrument in both operating modes showed that the spectral lines were basically the same.After the load launch,the instrument is tested in orbit,and its function and performance in orbit are analyzed.The feasibility of the ground-based spectral calibration scheme is verified.The method of in-orbit radiation calibration of the payload is introduced,and the absolute radiation calibration accuracy of EMI-Ⅱ is obtained by obtaining the same target detection data of EMI-Ⅱ and other payloads at the same date and similar transit location. |
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