Research On Weather Radar Factors Calibration And Rainfall Retrieval Based On Gis

As a kind of tool to estimating the precipitation, the weather radar is playing more and more important roles in monitoring and alarming crisis weather. The weather radars should be rapidly constructed in our country to improving the accuracy on estimating the precipitation with weather radar for social development and people's lives during the11th Five-Year Plan. ,but the radars newly installed use the default Z-I relationship to calculate the rainfall in the process of estimating the precipitation, such as the 713 digital Radar, which can't offer accurate precipitation,So it will greatly improve the radars'using efficiency that we calibrate radar factors of A and b in Z-I relationship to localize the weather radars.The Geographic Information System (GIS), a kind of important spatial technology, is earning more importance in the information construction for its function of drawing, data management, and spatial analysis. so it is very important to use GIS technology in the research on estimating the precipitation with radar to increase the accuracy.The paper mainly focuses on the technology and its implementation of weather radar factors calibration and rainfall retrieval based on GIS, including three aspects, which is weather radar factors calibration, rainfall retrieval, design and implementation of Weather radar factors calibration and rainfall retrieval system based on GIS.1. Weather radar factors calibration. Firstly, this paper explains the purpose of calibrating weather radar factors, analyses the theory of radar rainfall estimates ,and then gives some key technique of calibrating weather radar factors, including Time Weight Average Method, Space Orientation Manage,Space-time calibration on GIS and Rainfall calibration with ombrometers. At last,the paper designs the blue print of weathe radar factors calibration using these key technique.2. Rainfall retrieval. Based on completing weather radar factors calibration, the paper pretreats radar echo data with some methods, such as Time Weight Average Method, Space Orientation Manage and so on. then the paper puts forward two methods to retrieving rainfall on GIS which is layer superposed retrieval and raster graphics direct retrieval.3. Based on what we have done, the paper analyses the feasibility and needs of Weather radar factors calibration and rainfall retrieval system based on GIS, designs the data base, and develops the system based on the MapX by SQL Server 2000 and Visual C++. This paper specially research on fulfilling to integrate the radar echo data and rain data of ombrometers on the ground, displaying maps, and preprocessing original data, the system resolves some problems which include the coherent displaying of the radar echo data and rain data of ombrometers in time and space, the influence of rainfall by time series and interative calibration. the research could improve the accuracy of estimating the precipitation with weather radar through calibrating radar factors and retrieving rainfall .