Real-time retrieval of precipitable water vapor from GPS and BeiDou observations

The rapid development of the Chinese BeiDou Navigation Satellite System (BDS) brings a promising prospect for the real-time retrieval of zenith tropospheric delays (ZTD) and precipitable water vapor (PWV), which is of great benefit for supporting the time-critical meteorological applications such as nowcasting or severe weather event monitoring. In this study, we develop a real-time ZTD/PWV processing method based on Global Positioning System (GPS) and BDS observations. The performance of ZTD and PWV derived from BDS observations using real-time precise point positioning (PPP) technique is carefully investigated. The contribution of combining BDS and GPS for ZTD/PWV retrieving is evaluated as well. GPS and BDS observations of a half-year period for 40 globally distributed stations from the International GNSS Service Multi-GNSS Experiment and BeiDou Experiment Tracking Network are processed. The results show that the real-time BDS-only ZTD series agree well with the GPS-only ZTD series in general: the RMS values are about 11–16 mm (about 2–3 mm in PWV). Furthermore, the real-time ZTD derived from GPS-only, BDS-only, and GPS/BDS combined solutions are compared with those derived from the Very Long Baseline Interferometry. The comparisons show that the BDS can contribute to real-time meteorological applications, slightly less accurately than GPS. More accurate and reliable water vapor estimates, about 1.3–1.8 mm in PWV, can be obtained if the BDS observations are combined with the GPS observations in the real-time PPP data processing. The PWV comparisons with radiosondes further confirm the performance of BDS-derived real-time PWV and the benefit of adding BDS to standard GPS processing.

[1]  J. Saastamoinen.  Contributions to the theory of atmospheric refraction , 1972 .

[2]  J. Saastamoinen,et al.  Contributions to the theory of atmospheric refraction , 1972 .

[3]  I. Shapiro,et al.  Geodesy by radio interferometry: Effects of atmospheric modeling errors on estimates of baseline length , 1985 .

[4]  Jan Askne,et al.  Estimation of tropospheric delay for microwaves from surface weather data , 1987 .

[5]  T. Herring,et al.  GPS Meteorology: Remote Sensing of Atmospheric Water Vapor Using the Global Positioning System , 1992 .

[6]  J. Zumberge,et al.  Precise point positioning for the efficient and robust analysis of GPS data from large networks , 1997 .

[7]  Christian Rocken,et al.  Near real‐time GPS sensing of atmospheric water vapor , 1997 .

[8]  Michael Bevis,et al.  GPS meteorology: Reducing systematic errors in geodetic estimates for zenith delay , 1998 .

[9]  Hans van der Marel,et al.  Ground-Based GPS for Climate and Numerical Weather Prediction Applications , 2001 .

[10]  Rapid Retrieval and Assimilation of Ground Based GPS-Met Observations at the NOAA Forecast Systems Laboratory: Impact on Weather Forecasts , 2003 .

[11]  J. Kouba.  A GUIDE TO USING INTERNATIONAL GNSS SERVICE (IGS) PRODUCTS , 2003 .

[12]  Barry E. Schwartz,et al.  Rapid retrieval and assimilation of ground based GPS precipitable water observations at the NOAA Forecast Systems Laboratory: Impact on weather forecasts , 2004 .

[13]  Galina Dick,et al.  Near Real Time GPS Water Vapor Monitoring for Numerical Weather Prediction in Germany , 2004 .

[14]  Hans van der Marel,et al.  Synergetic Use of GPS Water Vapor and Meteosat Images for Synoptic Weather Forecasting , 2004 .

[15]  Junhong Wang,et al.  Global estimates of water‐vapor‐weighted mean temperature of the atmosphere for GPS applications , 2005 .

[16]  H. Schuh,et al.  Global Mapping Function (GMF): A new empirical mapping function based on numerical weather model data , 2006 .

[17]  H. Schuh,et al.  Combination of long time-series of troposphere zenith delays observed by VLBI , 2007 .

[18]  Tobias Nilsson,et al.  Long-term trends in the atmospheric water vapor content estimated from ground-based GPS data , 2008 .

[19]  Axel Nothnagel,et al.  Conventions on thermal expansion modelling of radio telescopes for geodetic and astrometric VLBI , 2009 .

[20]  Chris Rizos,et al.  The International GNSS Service in a changing landscape of Global Navigation Satellite Systems , 2009 .

[21]  Maorong Ge,et al.  Estimates of the information provided by GPS slant data observed in Germany regarding tomographic applications , 2009 .

[22]  Peter Steigenberger,et al.  Multi-technique comparison of troposphere zenith delays and gradients during CONT08 , 2011 .

[23]  Gunnar Elgered,et al.  Multi-technique comparisons of 10 years of wet delay estimates on the west coast of Sweden , 2012, Journal of Geodesy.

[24]  Xiaohong Zhang,et al.  Regional reference network augmented precise point positioning for instantaneous ambiguity resolution , 2011 .

[25]  Yuanxi Yang,et al.  Contribution of the Compass satellite navigation system to global PNT users , 2011 .

[26]  Harald Schuh,et al.  VLBI: A fascinating technique for geodesy and astrometry , 2012 .

[27]  Chuang Shi,et al.  Precise orbit determination of Beidou Satellites with precise positioning , 2012, Science China Earth Sciences.

[28]  Maorong Ge,et al.  A method for improving uncalibrated phase delay estimation and ambiguity-fixing in real-time precise point positioning , 2013, Journal of Geodesy.

[29]  Maorong Ge,et al.  The GFZ real-time GNSS precise positioning service system and its adaption for COMPASS , 2013 .

[30]  Maorong Ge,et al.  Estimating Zenith Tropospheric Delays from BeiDou Navigation Satellite System Observations , 2013, Sensors.

[31]  O. Montenbruck,et al.  IGS-MGEX: Preparing the Ground for Multi-Constellation GNSS Science , 2013 .

[32]  T. Nilsson,et al.  GPT2: Empirical slant delay model for radio space geodetic techniques , 2013, Geophysical research letters.

[33]  Maorong Ge,et al.  Real‐time high‐rate co‐seismic displacement from ambiguity‐fixed precise point positioning: Application to earthquake early warning , 2013 .

[34]  Maorong Ge,et al.  Real‐time GPS sensing of atmospheric water vapor: Precise point positioning with orbit, clock, and phase delay corrections , 2014 .

[35]  Fuyang Ke,et al.  Tropospheric wet refractivity tomography based on the BeiDou satellite system , 2014, Advances in Atmospheric Sciences.

[36]  Jan Douša,et al.  Real-time zenith tropospheric delays in support of numerical weather prediction applications , 2014 .

[37]  Witold Rohm,et al.  Real‐time retrieval of precipitable water vapor from GPS precise point positioning , 2014 .

[38]  Qile Zhao,et al.  Assessment of precipitable water vapor derived from ground-based BeiDou observations with Precise Point Positioning approach , 2015 .

[39]  Harald Schuh,et al.  Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou , 2015, Scientific Reports.