Inversion And Quality Evaluation Of Atmospheric Parameters And ABLH Of Multi GNSS Occultation Mission

Radio occultation(RO)technology is one of the main technologies to obtain global scale high vertical resolution atmospheric parameters.However,there are many problems such as signal interruption and low signal-to-noise ratio when observing the complex and changeable low-level atmosphere with serious signal attenuation.To solve those problems,the Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)-2 has improved the software and hardware capabilities and the ability of low-level atmosphere observation.In order to verify the ability of COSMIC-2 to retrieve neutral atmospheric parameters and atmospheric detection,this paper detects the neutral atmospheric parameters including atmospheric temperature and specific humidity parameters and atmospheric boundary layer height(ABLH)based on its observation data,complements the global neutral atmospheric parameter inversion with the occultation data of FY-3D.And evaluates the quality of the inversion results comprehensively.In addition,the global electron density(ED),total electron content(TEC)and ionospheric characteristic parameters are retrieved and evaluated based on COSMIC data to supplement the occultation detection of various altitude regions of the earth’s atmosphere.The specific work contents are as follows:(1)Based on COSMIC-2 and FY-3D occultation observation data,the neutral atmospheric parameters and detection of extreme weather are retrieved and studied.Combination with the ROPP and RO ionospheric parameter inversion program,the GNSS-RO inversion software is developed.The neutral atmospheric parameters are retrieved by using the observation data of COSMIC-2 and F Y-3D occultation missions in October 2019 and January,April and July 2020,and the quality analysis is carried out by using the corresponding official products(UCAR/NSMC)and Radiosonde data.The assessment results of atmospheric temperature and specific humidity parameters of COSMIC-2 show good accuracy.The evaluation results of official products are better than those of Radiosonde data,and the accuracy of FY-3D is worse than that of COSMIC-2.In addition,this paper uses the occultation data of the above two occultation systems and METOP to detect the rainstorm in Henan and typhoon "YanHua".The results show that the occultation data can characterize the change trend of meteorological events.(2)Inversion of ionospheric parameters based on COSMIC observation data.Using COSMIC 2009 occultation data to retrieve ED and TEC.UCAR products,global ionospheric map(GIM)and Ionosonde data are selected as reference data to evaluate the accuracy of the inversion results.It shows that both ED and TEC show high accuracy,as well as the ionospheric characteristic parameters.The peak electron density height of F2 layer(HmF2)is greatly affected by space-time matching,a lower correlation appeared.(3)Using COSMIC-2 data to detect and analyze ABLH.COSMIC-2 refractivity data from October 2019 to September 2020 are used to detect ABLH,and detection results are assessed by UCAR products and Radiosonde data to analyze the accuracy.The results show that COSMIC-2 ABLH is in good agreement with the detection results of UCAR products and Radiosonde data,and the evaluation results of UCAR products are better than radiosonde data.In addition,we grid the detected ABLH and analyze its variation features by the seasonal scale.The results show that COSMIC-2 ABLH can accurately characterize the temporal and spatial variation of ABLH in tropical and subtropical areas.