Real-Time Tropospheric Delays Retrieved from Multi-GNSS Observations and IGS Real-Time Product Streams
Real-Time Tropospheric Delays Retrieved from Multi-GNSS Observations and IGS Real-Time Product Streams
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DOI：
10.3390/rs9121317
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
Cuixian Lu;Xinghan Chen;Gen Liu;G. Dick;J. Wickert;Xinyuan Jiang;K. Zheng;H. Schuh
中科院分区：
文献类型：
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作者：
Cuixian Lu;Xinghan Chen;Gen Liu;G. Dick;J. Wickert;Xinyuan Jiang;K. Zheng;H. Schuh
多星座全球导航卫星系统(GNSS)为实时(RT)大气参数的提取提供了很大的潜力，以支持对时间要求苛刻的气象应用，例如现在预报或区域短期预报。在这项研究中，我们处理了来自全球分布的多GNSS实验(MGEX)网络的大约30个地面站的GNSS数据，使用精确单点定位(PPP)技术来反演RT多GNSS对流层延迟。使用了RT卫星轨道和国际全球导航卫星系统服务(IGS)的时钟产品流。同时，我们评估了不同IGS RT服务提供的时钟和轨道产品的质量，分别为CLK01、CLK81、CLK92、GFZC2和GFZD2。利用RT轨道和时钟产品，通过与美国海军天文台(USNO)最终对流层产品的比较，评估了从单系统和多个GNSS组合观测中反演的RT天顶总延迟(ZTD)的性能。通过添加多个GNSS观测值，可以获得与单系统解相比具有更高精度和更高可靠性的RTZTD估计。与仅使用全球定位系统(GPS)的方案相比，双系统和四系统组合的ZTD估计的初始化时间分别缩短了约5.8%和8.1%。用GFZC2产品检索的RT ZTD估计比从其他IGS-RT产品得到的估计要好。在GFZC2解中，通过固定站坐标，可以获得约5.05 mm的RT估计ZTD的精度。结果还证实，与仅使用GPS解相比，使用多个GNSS观测值可以提高实时估计ZTDS的精度(约22.2%)。在多GNSS解算中，与运动学模式相比，在固定坐标模式下，实时反演ZTDS的精度可提高2.7倍。
The multi-constellation Global Navigation Satellite Systems (GNSS) offers promising potential for the retrieval of real-time (RT) atmospheric parameters to support time-critical meteorological applications, such as nowcasting or regional short-term forecasts. In this study, we processed GNSS data from the globally distributed Multi-GNSS Experiment (MGEX) network of about 30 ground stations by using the precise point positioning (PPP) technique for retrieving RT multi-GNSS tropospheric delays. RT satellite orbit and clock product streams from the International GNSS Service (IGS) were used. Meanwhile, we assessed the quality of clock and orbit products provided by different IGS RT services, called CLK01, CLK81, CLK92, GFZC2, and GFZD2, respectively. Using the RT orbit and clock products, the performances of the RT zenith total delays (ZTD) retrieved from single-system as well as from multi-GNSS combined observations were evaluated by comparing with the U.S. Naval Observatory (USNO) final troposphere products. With the addition of multi-GNSS observations, RT ZTD estimates with higher accuracy and enhanced reliability compared to the single-system solution can be obtained. Compared with the Global Positioning System (GPS)-only solution, the improvements in the initialization time of ZTD estimates are about 5.8% and 8.1% with the dual-system and the four-system combinations, respectively. The RT ZTD estimates retrieved with the GFZC2 products outperform those derived from the other IGS-RT products. In the GFZC2 solution, the accuracy of about 5.05 mm for the RT estimated ZTD can be achieved with fixing station coordinates. The results also confirm that the accuracy improvement (about 22.2%) can be achieved for the real-time estimated ZTDs by using multi-GNSS observables, compared to the GPS-only solution. In the multi-GNSS solution, the accuracy of real-time retrieved ZTDs can be improved by a factor of up to 2.7 in the fixing coordinate mode, compared with that in the kinematic mode.