Study Of The Theory And Application To Realtime Remote Sensing Using Ground-based GPS

Water vapor changes in time and space weather forecasting especially around 100km horizontal scale, life history only a few hours of small-scale severe weather (rain, hail, thunderstorms, strong winds, tornadoes, etc.) monitoring and forecasting are particularly important implications. As a new foundation GPS atmospheric sounding instruments, its high time resolution, does not require calibration, device utilization, has become an important complement to atmospheric sounding instruments, and the weather forecast predicted on improving business systems, enhance short-term weather forecasts near system construction, good disaster, critical, major weather shifts and trends in drought and flood warning and forecast climate into the role great. Will allow our disaster prevention and mitigation, sustainable development to a new level, so as to achieve important social and economic benefits.At home and abroad have carried out a large number of ground GPS water vapor remote sensing research, and to business operations, but how to further improve the accuracy of ground GPS water vapor sensing and real-time monitoring of changes in atmospheric water vapor existing theories still need to further improve the algorithm.In this paper, the current GPS ground water vapor remote sensing technology in some of the key technologies of analysis and research, and based on real-time weather forecasting business needs of the real-time remote sensing of water vapor method.This paper studies:1. Detailed description of the ground water vapor PWV GPS zenith remote sensing methods. Focuses on remote sensing of total zenith tropospheric delay in the acquisition, the zenith wet delay means and methods of PWV obtained.2. Analysis of remote sensing ground GPS accuracy of the zenith water vapor number of factors. Focuses on ephemeris error, atmospheric loading, ocean loading, to obtain the absolute zenith delay factors in-depth research and analysis for example.3. Focuses on the tropospheric delay in the mapping function and its low height option. First introduced the commonly used mapping function models, followed by the combination of changes in water vapor image MODIS maps and GPS PWV analysis in the low-altitude mapping functions for different choices, come VMF1 real-time weather mapping function to better meet the changing needs of water vapor, but their needs external data, and the highest accuracy, GMF mapping function accuracy of the second, it can be replaced after the data processing VMF1 mapping function, NMF mapping function accuracy of the weakest.4. According to the weather forecast for the real needs of real-time access to PWV were studied. First, wet delay for the current model of low precision and made use of external inversion of wet weather data in near real time delay. Based on the European ECMWF water vapor data for the reliability of the wet delay and interpolation algorithm analysis, and taking into account the impact of elevation on the interpolation algorithm; followed by inversion of the MODIS images wet delay with GPS and access to the true value comparative analysis, fitting the relationship between the two and make the external meteorological data to calculate the wet delay and the integration of regional wet tropospheric delay model for near real-time single epoch algorithm, and precise point positioning (PPP) in; Finally, the research foundation based GPS double difference method of Kalman filter real-time dynamic monitoring of changes in the method of water vapor, and verify that this method changes in real-time dynamic monitoring of atmospheric water vapor the correctness and feasibility.