| Water vapor is an important part of the atmosphere and is closely related to people's daily life and production.Therefore,people's desire for meteorological knowledge and forecasting meteorological changes is also increasing.Ground-based GPS meteorology is a new type of water vapor detection method that integrates multiple disciplines such as surveying and mapping,meteorology,etc.It has the characteristics of high spatial and temporal resolution,high precision,high real-time and all-weather observation.Especially with the improvement of GPS positioning accuracy and the establishment of a large-scale CORS network nationwide,ground-based GPS meteorology has entered the fast lane of development.Although a series of research results have been obtained through the inversion of water vapor data from GPS data,it is not perfect and needs further study.In view of this,this paper studies water vapor inversion and tomography from the aspects of method implementation,accuracy evaluation and influencing factors.The main research contents of this paper are as follows:(1)Based on die introduction of ground-based GPS water vapor inversion,the factors affecting the accuracy of water vapor inversion are analyzed,and the accuracy test and evaluation method of water vapor inversion were given.The principles and methods in the process of GPS signal propagation,especially tropospheric delay,and tropospheric delay inversion of atmospheric precipitable water PWV and three-dimensional water vapor chromatography were briefly described.(2)The water vapor inversion experiment was carried out using the GPS data of 18 stations in the CORS network in Hong Kong.The GAMIT software was used to perform a baseline calculation of the data and to reverse the PWV of precipitation in Hong Kong.Compared with the meteorological data of the King's Park sounding station in Hong Kong,the average deviation between GPS/PWV and Radio/PWV is 0.25mm and the root mean square error is 1.76mm,which meets the accuracy requirements of water vapor solution.Through the analysis of a rainfall process in Hong Kong,the precipitation can be consistent with the actual precipitation distribution,which proves that the atmospheric precipitation can accurately and accurately reflect the water vapor in the atmosphere.(3)The study analyzed some of the influencing factors that occurred during the inversion of precipitation PWV.Through the analysis of the data of Hong Kong King's Park Sounding Station,the Hong Kong weighted average temperature localization calculation model was established to obtain the atmospheric weighted average temperature more suitable for Hong Kong;and then by using different ephemeris,different atmospheric weighted average temperature models and different tropospheric delay models were used to process the data of Hong Kong CORS network,and the inversion can obtain the PWV of precipitation.The influence of these factors on the accuracy of the inversion results was analyzed.(4)In this paper,the solution method of precipitation SWV in the direction of oblique path and the 3D tomography technology were briefly introduced,and the tomography area was divided into grid,the tomography equations were established,and finally the tomography experiment was earied out to obtain three kinds of water vapor products:water vapor contour line,water vapor 3D distribution magram and water vapor stratification distribution diagram.Figure[23]table[15]reference[99]... |
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