【作者】 朱庆林；

【导师】 吴振森； 赵振维；

【作者基本信息】 西安电子科技大学 ， 无线电物理， 2010， 博士

【摘要】 全球导航卫星系统(GNSS)不仅成功应用于测距、授时和导航等传统领域,而且在环境监测、大地测量、天文、气象等领域也得到广泛的应用。单站地基GNSS对电波折射参数的估计,由于操作简单、成本低、可移动性强以及精度高等优点,已成为当前国际研究的热点。本文以GNSS单点定位方法为出发点,围绕电波折射参数的高精度实时估计、实验验证和应用开展了相关研究。其主要研究成果如下:第一、分析了单点定位的主要误差源和修正方法,主要包括卫星误差、接收机误差以及空间传播误差等。讨论了传统随机模型的特点,提出了基于新权矩阵的随机模型,并对比分析了上述两类模型的对流层天顶延迟估计结果。第二、讨论了对流层天顶延迟的传统的Hopfield模型、Saastamoinen模型和MOPS模型以及探空方法在测量天顶延迟方面存在的局限性。在精密单点定位方法的基础之上,利用提出的随机模型,实现了单站地基GNSS对流层天顶延迟的估计。获得单站地基GPS与探空观测结果一致,与IGS产品中利用GIPSY软件计算精度相当的结果。第三、研究了低仰角对流层斜延迟估计方法。分析了现有映射函数、经验模型和探空观测方法的局限性,提出了单站地基GNSS实时估计低仰角对流层斜延迟的方法。利用2008年8月期间实验数据,进行单站地基GPS低仰角对流层斜延迟估计,获得与探空实验一致的结果,优于传统模型估计结果。实现了单站地基GNSS对低仰角的对流层斜延迟的估计。第四、研究了单站地基GNSS实时估计弯曲角。讨论了传统模型和探空折射率剖面计算弯曲角的方法,分析卫星信号的多普勒频移与弯曲角之间的关系,以及GNSS的多普勒观测值中的误差对计算弯曲角的影响。利用单站地基GNSS的数据和GNSS多普勒频移公式,对弯曲角的估计,获得与基于探空折射率剖面一致的结果,提出了单站地基GNSS实时估计弯曲角的方法。第五、提出了基于单站地基GNSS实时反演折射率剖面方法,利用汕头地区十年的历史数据进行仿真,初步验证了此方法的可行性。在我国广东东南沿海地区开展了单站地基GPS的观测实验,利用低仰角斜延迟进行了大气剖面实时反演和数据分析,验证了此方法的可行性和有效性。更多还原

【Abstract】 The Global Navigation Satellite System (GNSS) have been applied successfully not only in the traditional field such as ranging, time service, and navigation, but also in environmental monitoring, geodesy, astronomy, and meteorology and so on. Estimation of electromagnetic wave refraction parameters based on singular ground-based GNSS has been one of hot topics in the international area. On the basis of theoretical study on GNSS point positioning, real time and high accuracy estimation of electromagnetic wave refraction parameters, experimental verification and application are studied in this dissertation. The main topics and results of the study are as follows:First, main errors consist of satellite error, receiver error, and space propagation error in GNSS point positioning, and corrected methods are analyzed. The characteristic of traditional stochastic models are discussed, and a new stochastic model is introduced. Two results of zenith tropospheric delay estimation by the above two stochastic models are compared and analyzed.Second, traditional models, for example, Hopfield model, Saastaoinen model and MOPS model, and radiosonde measuring zenith tropospheric delay are discussed, as well as their limitation. Based on precise point positioning and introducing stochastic model, the zenith tropospheric delay estimation by singular ground-based GNSS is realized. Results of GNSS agree well with those of radiosonde, the precision of GNSS have the same order with IGS products which are computed by GIPSY.Third, the estimation means of real time slant path tropospheric delay calculation at very low elevation are studied systemically. The limitations of existent mapping function, experiential model and radiosonde are analyzed in detail. A method of computing real time tropospheric slant delay at low elevation by singular ground-based GNSS is introduced. Observations in August 2008 are disposed. The corresponding results have well agreement with those of radiosonde, and are better than those of conventional models. Consequently, the estimation by singular ground-based GNSS is implemented.Fourth, real time bending angle estimation by singular ground-based GNSS station is studied. The previous methods of calculating the bending angles based on refractivity profile from refractivity climatology model and radiosonde are presented. The relationship of bending angle of radio waves with Doppler frequency shift is given and analyzed in detail. Main error sources of Doppler observations are presented and discussed. Some singular ground-based GPS observation and radiosonde measurements are analyzed. The bending angles calculating from Doppler agree fairly well with those from radiosondes. The method that is based on singurlar ground-based GNSS is introduced.Fifth, the real time inversion method of refractivity profile based on singular gound-based GNSS is introduced. Emulation is achieved by ten years historical data in Shantou and the feasibility is validated initiativly. A singular ground-based GPS observation experiment in eastsouth china is carried out. The real time inversion of refractivity profile is implemented and detailed analyzed. The feasibility and effectiveness is validated.更多还原