Augmenting GNSS PPP Accuracy in South China Using Water Vapor Correction Data from WRF Assimilation Results

Yangzhao Gong, Zhizhao Liu, Pak Wai Chan, Kai Kwong Hon

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

2 Citations (Scopus)


Wet delay in Global Navigation Satellite System (GNSS), mainly caused by water vapor in the atmosphere, is difficult to be accurately modeled using empirical wet delay models as water vapor is highly variable in both space and time. In this paper we propose correcting the GNSS wet delay using water vapor data from Weather Research and Forecasting (WRF) model’s assimilation results. We conduct six consecutive 24-h WRF forecasts to model the three-dimension (3D) distribution of water vapor in the South China region 20° N–33° N and 108° E–123° E from 0 h UTC April 06, 2020 to 0 h UTC April 11, 2020. GNSS Precipitable Water Vapor (PWV) from 27 stations of the Crustal Movement Observation Network of China (CMONOC) and meteorological profiles from 22 radiosonde stations are assimilated into WRF model to improve the water vapor modeling performance of WRF. Totally, four WRF schemes are adopted, i.e. WRF scheme 0: WRF without water vapor data assimilation; WRF scheme 1: WRF with GNSS PWV assimilation only; WRF scheme 2: WRF with radiosonde profiles assimilation only; WRF scheme 3: WRF with both GNSS PWV and radiosonde profiles assimilation. The water vapor data from the four WRF schemes are used to augment Precise Point Positioning (PPP) by correcting GNSS wet delay at seven International GNSS Service (IGS) stations distributed in South China. The static PPP results show that using the water vapor correction data from different WRF schemes can improve PPP positioning accuracy by 29.5% to 42.3% in the vertical component of GNSS stations. In addition, the WRF-augmented PPP can shorten convergence time by 43.3% to 57.3% in the GNSS station vertical component, if using 10 cm positioning error as the convergence criterion. The kinematic PPP results show that WRF-augmented PPP can improve positioning accuracy in the vertical component by 20.0% to 33.6%.

Original languageEnglish
Title of host publicationChina Satellite Navigation Conference, CSNC 2021, Proceedings
EditorsChangfeng Yang, Jun Xie
PublisherSpringer Science and Business Media Deutschland GmbH
Number of pages18
ISBN (Print)9789811631375
Publication statusPublished - May 2021
Event12th China Satellite Navigation Conference, CSNC 2021 - Nanchang, China
Duration: 22 May 202125 May 2021

Publication series

NameLecture Notes in Electrical Engineering
Volume772 LNEE
ISSN (Print)1876-1100
ISSN (Electronic)1876-1119


Conference12th China Satellite Navigation Conference, CSNC 2021


  • Data assimilation
  • Global Navigation Satellite System (GNSS)
  • Precipitable Water Vapor (PWV)
  • Precise Point Positioning (PPP)
  • Weather Research and Forecasting (WRF) model

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering


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