Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring

Baldysz, Zofia; Nykiel, Grzegorz; Araszkiewicz, Andrzej; Figurski, Mariusz; Szafranek, Karolina

doi:10.5194/amt-9-4861-2016

Cited by 21 publications

(16 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this data set is quite sparse over Europe (only 85 stations over the 280 EPN stations) and covers only the period 1996-2010. As pointed by Baldysz et al (2015Baldysz et al ( , 2016 an additional 2 years of ZTD data can change the estimated trends up to 10 %. Therefore, with data after 2010 and with a better coverage over Europe, EPN-Repro2 can be used as a reference data set with a high potential for monitoring the trends and variability in atmospheric water vapour as reported in Sect.…”

Section: Discussionmentioning

confidence: 99%

EPN-Repro2: A reference GNSS tropospheric data set over Europe

Pacione

Araszkiewicz

Bröckmann³

et al. 2017

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

Abstract. The present availability of 18+ years of GNSS data belonging to the EUREF Permanent Network (EPN, http://www.epncb.oma.be/) is a valuable database for the development of a climate data record of GNSS tropospheric products over Europe. This data record can be used as a reference for a variety of scientific applications (e.g. validation of regional numerical weather prediction reanalyses and climate model simulations) and has a high potential for monitoring trends and the variability in atmospheric water vapour. In the framework of the EPN-Repro2, the second reprocessing campaign of the EPN, five Analysis Centres homogenously reprocessed the EPN network for the period 1996-2014. A huge effort has been made to provide solutions that are the basis for deriving new coordinates, velocities and tropospheric parameters for the entire EPN. The individual contributions are then combined to provide the official EPN reprocessed products. This paper is focused on the EPN-Repro2 tropospheric product. The combined product is described along with its evaluation against radiosonde data and European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA-Interim) data.

show abstract

Section: Discussionmentioning

confidence: 99%

EPN-Repro2: A reference GNSS tropospheric data set over Europe

Pacione

Araszkiewicz

Bröckmann³

et al. 2017

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the individual station trend provided in the Supplement could be compared to other studies -e.g. Baldysz et al (2016), Klos et al (2016), or Nilsson and Elgered (2008) -it should be strongly emphasized here that our trends are estimated without any preceding time-series homogenization and the formal errors of the trend estimates are underestimated by a factor 2-4 (Nilsson and Elgered, 2008). Statistics GO1-GO0 GO2-GO1 GO3-GO1 GO4-GO1 GO5-GO4 GO6-GO4 Table 6 summarizes the statistics of estimated trend differences at all 172 stations, always between particular variants as defined in Sect.…”

Section: Impact Of Variants On Long-term Ztd Trend Estimatesmentioning

confidence: 99%

Tropospheric products of the second GOP European GNSS reprocessing (1996–2014)

2017

View full text Add to dashboard Cite

Abstract. In this paper, we present results of the second reprocessing of all data from 1996 to 2014 from all stations in International Association of Geodesy (IAG) Reference Frame Sub-Commission for Europe (EUREF) Permanent Network (EPN) as performed at the Geodetic Observatory Pecný (GOP). While the original goal of this research was to ultimately contribute to the realization of a new European Terrestrial Reference System (ETRS), we also aim to provide a new set of GNSS (Global Navigation Satellite System) tropospheric parameter time series with possible applications to climate research. To achieve these goals, we improved a strategy to guarantee the continuity of these tropospheric parameters and we prepared several variants of troposphere modelling. We then assessed all solutions in terms of the repeatability of coordinates as an internal evaluation of applied models and strategies and in terms of zenith tropospheric delays (ZTDs) and horizontal gradients with those of the ERA-Interim numerical weather model (NWM) reanalysis. When compared to the GOP Repro1 (first EUREF reprocessing) solution, the results of the GOP Repro2 (second EU-REF reprocessing) yielded improvements of approximately 50 and 25 % in the repeatability of the horizontal and vertical components, respectively, and of approximately 9 % in tropospheric parameters. Vertical repeatability was reduced from 4.14 to 3.73 mm when using the VMF1 mapping function, a priori ZHD (zenith hydrostatic delay), and non-tidal atmospheric loading corrections from actual weather data. Raising the elevation cut-off angle from 3 to 7 • and then to 10 • increased RMS from coordinates' repeatability, which was then confirmed by independently comparing GNSS tropospheric parameters with the NWM reanalysis. The assessment of tropospheric horizontal gradients with respect to the ERA-Interim revealed a strong sensitivity of estimated gradients to the quality of GNSS antenna tracking performance. This impact was demonstrated at the Mallorca station, where gradients systematically grew up to 5 mm during the period between 2003 and 2008, before this behaviour disappeared when the antenna at the station was changed. The impact of processing variants on long-term ZTD trend estimates was assessed at 172 EUREF stations with time series longer than 10 years. The most significant site-specific impact was due to the non-tidal atmospheric loading followed by the impact of changing the elevation cut-off angle from 3 to 10 • . The other processing strategy had a very small or negligible impact on estimated trends.

show abstract

“…The 24-h forecasting products (ZHD, ZWD and VMF1 coefficients) have a good performance and, thus, are also examined in our real-time PPP analysis [29]. In the PPP processing, the slant tropospheric delays are calculated by mapping the zenith delays into the radio line-of-sight direction with the VMF1 since it is the most accurate mapping function for the entire history of space geodetic observations [29,30].…”

Section: Empirical Tropospheric Modelsmentioning

confidence: 99%

Real-Time Precise Point Positioning Using Tomographic Wet Refractivity Fields

Chen

Dai

et al. 2018

Remote Sensing

View full text Add to dashboard Cite

Abstract:The tropospheric wet delay induced by water vapor is a major error source in precise point positioning (PPP), significantly influencing the convergence time to obtain high-accuracy positioning. Thus, high-quality water vapor information is necessary to support PPP processing. This study presents the use of tomographic wet refractivity (WR) fields in PPP to examine their impacts on the positioning performance. Tests are carried out based on 1-year of 2013 global navigation satellite system (GNSS) observations (30 s sampling rate) from three stations with different altitudes in the Hong Kong GNSS network. Coordinate errors with respect to reference values at a 0.1 m level of convergence is used for the north, east, and up components, whilst an error of 0.2 m is adopted for 3D position convergence. Experimental results demonstrate that, in both static and kinematic modes, the tomography-based PPP approach outperforms empirical tropospheric models in terms of positioning accuracy and convergence time. Compared with the results based on traditional, Saastamoinen, AN (Askne and Nordis), and VMF1 (Vienna Mapping Function 1) models, 23-48% improvements of positioning accuracy, and 5-30% reductions of convergence time are achieved with the application of tomographic WR fields. When using a tomography model, about 35% of the solutions converged within 20 min, whereas only 23%, 25%, 25%, and 30% solutions converged within 20 min for the traditional, Saastamoinen, AN, and VMF1 models, respectively. Our study demonstrates the benefit to real-time PPP processing brought by additional tomographic WR fields as they can significantly improve the PPP solution and reduce the convergence time for the up component.

show abstract

Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring

Cited by 21 publications

References 40 publications

EPN-Repro2: A reference GNSS tropospheric data set over Europe

EPN-Repro2: A reference GNSS tropospheric data set over Europe

Tropospheric products of the second GOP European GNSS reprocessing (1996–2014)

Real-Time Precise Point Positioning Using Tomographic Wet Refractivity Fields

Contact Info

Product

Resources

About