应用iGMAS超快速星历的实时精密单点定位研究

中国主导建设的国际GNSS监测评估系统（iGMAS）相比国际上比较成熟的IGS系统在产品精度等方面存在差别，目前实时精密单点定位应用多采用IGS实时、近实时产品。为改变这一现状，针对iGMAS产品特性以及实时精密单点定位对超快速精密星历的需求，对iGMAS超快速星历的精度和稳定性方面进行评估，设计了iGMAS产品实时/事后下载应用程序，开展了基于iGMAS超快速星历的实时精密单点定位研究，并结合NovAtel OEM617双频接收机进行了GPS实时精密单点定位试验。实验结果表明，在连续观测23min后定位误差即可收敛到分米级，较接收机原始定位精度高一个量级，且稳定性好，最终在E/N/U方向定位误差均方根分别为7.2cm、6.4cm、15.2cm，与应用IGS超快速星历实时PPP试验取得相近的结果。研究实现了iGMAS数据获取、评估和实时PPP应用的一整套方案，验证了iGMAS超快速产品的性能，对推进iGMAS产品的应用提供了借鉴。

Research on real-time precise point positioning with iGMASultra-fast ephemeris#br#

The China-led International GNSS Monitoring & Assessment System (iGMAS) differs from the IGS system (international GNSS service, IGS) in product accuracy. Real-time precise point positioning(PPP) applications are mostly based on IGS real-time and near real-time products. To improve this situation, we aimed at iGMAS product characteristics and the demand for ultra-fast products with real-time PPP, evaluated the accuracy and stability of iGMAS ultra fast ephemeris, designed an iGMAS product real-time/post-event download application, and carried out real-time precise point positioning research based on iGMAS ultra-fast ephemeris through combining with NovAtel OEM617 dual-frequency receiver. The experimental results show that the positioning error can converge to the decimeter level after 23 minutes, which is an order of magnitude higher than the original positioning accuracy of the receiver and has good stability. The root mean square error of the positioning error in the E/N/U direction is 7.2cm, 6.4cm, 15.2cm, similar to IGS ultra-fast ephemeris in real-time PPP experiment. This study implements a complete solution for iGMAS data acquisition, evaluation, and real-time PPP applications, verifies performance of iGMAS ultra-fast products and provides reference for the application of iGMAS products.