Design Of Special Turntable For Radiometric Calibration Of Spaceborne Atmospheric Trace Gas Differential Absorption Spectrometer

The rapid growth of world industry and more human activities have deteriorated global environment greatly,which has also promoted research on environmental pollution monitoring.Advances in science and technology contribute to various approaches and methods to monitor environment.For atmospheric environment monitoring,atmospheric remote sensing technology,due to its unique advantages,has become one of the important ways to obtain global atmospheric conditions.The spaceborne atmospheric trace gas differential absorption spectrometer developed by the project team obtains global hyperspectral data through spectral imaging technology,and based on this,obtains the global atmospheric trace gas distribution and transmission.Based on the difference between the solar calibration optical path of the atmospheric trace gas differential absorption spectrometer and the ground observation optical path,in order to achieve the absolute radiance calibration based on sunlight in orbit,the radiation response relationship of the two observation optical paths on the ground is required to be the whole machine BSDF characteristics for calibration.In the development process of atmospheric trace gas differential absorption spectrometer,it is necessary to calibrate the spectrometer to verify whether its radiation response characteristics meet the application requirements.Based on this,the calibration devices of large-field imaging spectrometers at home and abroad are investigated based on satellite According to the optical system requirements of the mounted spectrometer,a dedicated turntable for radiation calibration is designed.Analyze and compare common two-dimensional turntables,combine the requirements of the spectrometer,determine the overall structure of the two-dimensional turntable,complete the design and verification of each structure,Select drive parts and use Solid Works to complete 3D solid modeling of the 2d calibration turntable.The table body part of the twodimensional turntable is the main working part,and the rigidity and strength of each structural member should have sufficient safety factors.Use finite meta-analysis software,ANSYS get on static structure and modal analysis of the turntable body are carried out,and the maximum stress,the maximum displacement,the first six natural frequencies and the mode shape diagram are obtained.According to the software simulation results,the structural design of the two-dimensional turntable is verified.The safety factor of the structural parts can be up to 6 times.The calibration turntable can achieve ±180° rotation in the horizontal direction and ±20° swing in the pitch direction,which meets the design specifications of the two-dimensional turntable.After the turntable is successfully manufactured,it will be applied to the calibration of the spectrometer and related test experiments,including the irradiance experiment of the solar calibration optical path and the spectral calibration experiment of the earth observation optical path.After analyzing and processing the data collected in the calibration experiment,the irradiance calibration coefficient of the solar calibration light path under different observation angles and the spectral resolution of the four channels of the spectrometer are obtained.The two-dimensional radiometric calibration turntable studied in this paper can meet the requirements of ground calibration and provide a guarantee for the calibration accuracy of the spectrometer.Based on the radiometric calibration coefficients obtained by this turntable,it will further improve the quantification of on-orbit remote sensing data from the spaceborne spectrometer.Application level.