【作者】 张健；

【导师】 刘焱雄；

【作者基本信息】 国家海洋局第一海洋研究所 ， 环境科学， 2011， 硕士

【摘要】 精密单点定位技术(PPP)的出现,改变了GNSS传统精密相对定位模式,对GNSS精密定位的广泛应用有着巨大的推进作用。精密单点定位技术的最大优势在于实时应用,目前实时动态精密单点定位技术也是GPS研究的热点和难点之一,其实时应用尚难以推广主要受到精密卫星钟差解算精度及钟差发布有一定潜伏期的制约。因此,基于区域GPS观测网络,系统研究精密卫星钟差解算方法,开发自主的精密卫星钟差解算软件,改善精密卫星钟差精度和时效性,对精密单点定位技术的实时应用具有重要的研究意义和应用价值。本文系统研究精密卫星钟差解算的基本理论和方法,详细讨论了精密卫星钟差解算中各个误差改正项及相关数学模型;然后,基于区域GPS观测网站推导建立了三种精密卫星钟差的解算模型,并依据无模糊度精密卫星钟差模型对算法进行了编程实现;最后,采用国家海洋局沿海GNSS业务化系统的观测数据,完成了区域精密卫星钟差的解算,并与IGS发布的事后发布的精密卫星钟差进行了比较分析。自编卫星钟差解算程序计算的事后精密卫星钟差结果精度约为0.5ns,由于卫星钟(铷钟和铯钟)的不同,不同卫星的钟差精度在0.5ns上下有所波动,这些结果与IGS下设的数据分析中心的结果精度类似。另外,在区域范围内,采用IGS发布的超快速预报精密星历,实时计算的精密卫星钟差结果精度也在0.5ns上下,可以达到与最终星历结果相当的精度,具备实时应用的潜力。更多还原

【Abstract】 The development of precise point positioning (PPP) technique is changing the GNSS traditional mode of precise relative positioning. And the extensive use of GNSS precise positioning played an important role in the promotion. The main advantage of PPP is the real-time and dynamic application, and the PPP becomes one of the research hotspot in GPS Technology. The real-time PPP application is limited by the real-time clock offsets estimates within a delay of a few seconds and its accuracy of GPS satellite. Therefore, it is quite important and valuable to study the estimation method of satellite clock offsets, develop the calculation software and improve the accuracy and timeliness of satellite clock offsets based on regional GPS reference network.The basic theories and methods of satellite clock offset estimation are systematically investigated in the paper. The major corrections and related mathematic models in calculating precise satellite clock offsets are discussed in detail. And then based regional GPS observations network, three models of estimating satellite clock offsets are derived. According to the satellite clock offsets estimation model without ambiguity resolution, a program for the precise satellite clock offsets estimation is developed. Finally, Clock offsets of the complete GPS constellation are estimated based on the GPS data from the SOA coastal GNSS observation network and our Clock offsets estimations are compared to the final IGS(the International GNSS Service) clock corrections. The results show that their agreement is about 0.5 nanoseconds between our satellite clock offsets results and the final IGS clock corrections. The accuracy of these results are similar to the those from IGS data analysis center. In addition, based on the regional GNSS network, the use of the predicted Ultra Rapid products from IGS, the accuracy of real-time satellite clock offsets is about 0.5 nanoseconds. It is nearly the same as those with the IGS Final GPS orbits. This result will help the further research on the real-time calculation and application of the satellite clock offset.更多还原