An assessment of the quality of near-real time GNSS observations as a potential data source for meteorology
Natalia Dymarska , Witold Rohm , Jan Sierny , Jan Kapłon , Tomasz Kubik , Maciej Kryza , Jerzy Jutarski , Jacek Gierczak , Ryszard Kosierb
AbstractThe Global Navigation Satellite System (GNSS) can be used to determine accurate and high-frequency atmospheric parameters, such as Zenith Total Delay (ZTD) or Precipitable Water Vapour (PW), in all-weather conditions. These parameters are often assimilated into Numerical Weather Prediction (NWP) models and used for now-casting services and climate studies. The effective usage of the ZTDs obtained from a ground-based GNSS receiver's network in a NWP could fill the gap of insufficient atmospheric water vapour state information. The supply of such information with a latency acceptable for NWP assimilation schemes requires special measures in the GNSS data processing, quality control and distribution. This study is a detailed description of the joint effort of three institutions-Wroclaw University of Environmental and Life Sciences, Wroclaw University, and the Institute of Meteorology and Water Management - to provide accurate and timely GNSS-based meteorological information. This paper presents accuracy analyses of near real-time GNSS ZTD validated against reference ZTD data: the International GNSS Service (IGS) from a precise GNSS solution, Weather Research and Forecasting (WRF) model, and radiosonde profiles. Data quality statistics were performed for five GNSS stations in Poland over a time span of almost a year (2015). The comparison of near real-time ZTD and IGS shows a mean ZTD station bias of less than 3 mm with a related standard deviation of less than 10 mm. The bias between near real-time ZTD and WRF ZTD is in the range of 5-11 mm and the overall standard deviation is slightly higher than 10 mm. Finally, the comparison of the investigated ZTD against radiosonde showed an average bias at a level of 10 mm, whereas the standard deviation does not exceed 14 mm. Considering the data quality, we assess that the NRT ZTD can be assimilated into NWP models.
|Journal series||Meteorology Hydrology and Water Management, ISSN 2299-3835, e-ISSN 2353-5652, (B 8 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||ZTD estimation; data validation; GNSS meteorology|
|Score||= 8.0, 02-09-2020, ArticleFromJournal|
|Publication indicators||= 9|
|Citation count*||10 (2020-09-28)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.