The Algorithms And SoftWare Developement Of Inversion The Refractive Of Atmosphere In Mountain-based GPS Occultation

The meteorological disaster is one of the factors affecting China's economic growth. Researches on forecasting, predicting and assessing methodologies of the meteorological disaster are of great significance to maintain the rapid development of the nation's economy and society.GPS/MET is an innovative discipline used to remote sense the earth atmosphere and to measure certain meteorologic elements, such as the refractive contour of the atmosphere, by the GPS technology. It has advantages of global coverage, low-cost, high accuracy and high vertical resolution. The mountain-based GPS/MET is a new atmospheric detection technology on the basis of the space-based GPS/MET. This technology involves the GPS receivers placed on the mountain top, of which the altitude is above 2000m. With the principle of the mountain-based GPS occultation inversion, we can process data to obtain the lower atmosphere parameters.This paper describes the principle and data-processing of the atmosphere refractive index by mountain-based GPS occultation inversion. Mountain-based GPS occultation inversion can be divided into three parts, including occultation prediction, data observation and data processing. This paper does an in-depth case study of the accurate occultation event forecast at first. Use the radio ephemeris and sophisticated forecasting ephemeris to computed the position and speed of satellite, comparison the difference of the methods and accuracy. To bring up the methods of use the sophisticated forecasting ephemeris for the occultation forecasting, achieved good results. In August 2005, I participated in a test ,which sponsored by National Satellite Meteorological Center, General Staff Department of Atmospheric Environment Institute, Beijing University, Tsinghua University, and other institute. The test is about mountain-based GPS occultation observation at Wuling Mountain in Hebei province, collected a large amount of satellite data and sounding data. Based on this, This paper in-depth study and research the principle of mountain-based GPS occultation inversion the refractive of atmosphere and data-processing methods. Include double-poor, cycle-slip detection and repair, the calculation of Doppler shift, computed the bending angle and parameters of the collision and the Abel integral transform inversion the refractive of atmosphere, and several other major steps, In this paper, the process carried out a detailed description, and the formula is derived, this paper focus on research the cycle-slip detection and repair, computed the bending angle and parameters of collision. And I had do software development for my research. Finally, I use this software to inversion the date of Wuling Mountain GPS Occultation test, and compare with the date of space-based. The date of refractive profiles of the atmosphere by two different ways is match pretty well. Proven that the methods and mathematical model of this paper is correct . The technology of mountain-based GPS occultation inversion is effective. This paper can provided a good foundation for further research and application of mountain-based GPS Occultation inversion the refractive of atmosphere.