Research On Near Infrared Radiative Transfer Characteristics For Atmospheric CO₂ Based On SCIATRAN

It is significant to study the high accuracy of atmospheric CO₂ detection for the accurate description of the spatial distribution of CO₂.Spatial heterodyne spectroscopy?SHS?is new remote sensing technique with high-throughput and super spectral resolution capability.At present,the research on the forward modeling model of this technology is still lacking.Therefore,this paper is proposed to study the forward modeling model of high precision radiation transmission.The forward model is important for the new detector performance simulation,optimizing the sensor system parameters,and provides reliable simulation data for accurate inversion of CO₂ concentration.In this paper,SCIATRAN model was used to carry out the forward modeling of atmospheric CO₂ spatial heterodyne spectroscopy,and a complete atmospheric CO₂ nearinfrared radiation transmission model was established.The influence of these factors on the spatial heterodyne spectroscopy of atmospheric CO₂ was analyzed by using the geometric,aerosol parameters and surface parameters as the sensitivity factors.And the simulated data were compared with the measured data.The results show that the CO₂ radiation intensity observed by CO₂ detector is not affected by the solar azimuth,aerosol season and boundary layer humidity.The primary factor affecting its observed brightness is the solar zenith angle,and the sun's zenith angle is reduced by 36% for every 10 ° increase.Followed by the impact of surface characteristics,different surfaces have different reflection characteristics,and when the surface albedo increases 0.1,the observed radiation brightness increases about 20%.The influence of different aerosol optical thickness and atmospheric boundary layer on the observed radiation brightness is also greater,the influence of urban aerosols and rural aerosols is consistent,the observed radiation decreases with the increase of the aerosol optical thickness,and increases with the visible distance.Marine aerosols are opposite to urban aerosols and rural aerosols.Finally,in the comparison between SCIATRAN simulation data and measured data and Modtran simulation data,it is shown that the three spectral shapes are similar and the trend is consistent.The feasibility and reliability of the SCIATRAN model as a forward model of CO₂ spatial heterodyne spectroscopy are verified,and the advantages of high resolution of SCIATRAN model are demonstrated.