Precyzyjne opracowanie obserwacji GPS w sieciach lokalnych nawiązanych do stacji permanentnych EPN/IGS

Tyt. z nagłówka.Bibliografia s. 100-101.Dostępny również w formie drukowanej.STRESZCZENIE: Sieci lokalne GPS opracowuje się w nawiązaniu do sieci stacji permanentnych IGS/EPN. Stacje permanentne IGS/EPN służą między innymi do realizacji ziemskiego układu odniesienia, wyznaczania precyzyjnych orbit satelitów GPS, modeli jonosfery oraz parametrów troposfery. Wykorzystanie powyższych wyników pozwala na przeniesienie realizacji układu odniesienia i podniesienie dokładności estymowanych parametrów na etapie opracowania sieci lokalnej. W artykule przedstawiono koncepcję opracowania sieci lokalnych GPS w nawiązaniu do stacji permanentnych IGS/EPN wraz z przykładami. SŁOWA KLUCZOWE: lokalne sieci GPS, opracowanie obserwacji GPS. ABSTRACT: The local GPS networks are processed in connection to permanent GNSS stations of EUREF Permanent Network (EPN) or/and International GNSS Service (IGS). The permanent GNSS stations are used for realization of Terrestrial Reference Frame (e.g. International Terrestrial Reference Frame), precise orbits determination and ionosphere and troposphere models. The products of above networks solutions give the possibility of reference frame realization and higher accuracy of estimated parameters in local GPS networks. In the paper the processing methodology of a local GPS network connected to IGS/EPN permanent stations and same examples has been presented. KEYWORDS: local GPS networks, GPS data processing

Global Geodetic Observing System 2015–2018

Global Geodetic Observing System (GGOS) was established in 2003 by the International Association of Geodesy (IAG) with the main goal to deepen understanding of the dynamic Earth system by quantifying human-induced Earth’s changes in space and time. GGOS allows not only for advancing Earth Science, including solid Earth, oceans, ice, atmosphere, but also for better understanding processes between different constituents forming the system Earth, and most importantly, for helping authorities to make intelligent societal decisions. GGOS comprises different components to provide the geodetic infrastructure necessary for monitoring the Earth system and global changes. The infrastructure spreads from the global scale, through regional, to national scales. This contribution describes the GGOS structure, components, and goals with the main focus on GGOS activities in Poland, including both the development of the geodetic observing infrastructure as well as advances in processing geodetic observations supporting GGOS goals and providing high-accuracy global geodetic parameters

Tropospheric refractivity and zenith path delays from least-squares collocation of meteorological and GNSS data

Precise positioning requires an accurate a priori troposphere model to enhance the solution quality. Several empirical models are available, but they may not properly characterize the state of troposphere, especially in severe weather conditions. Another possible solution is to use regional troposphere models based on real-time or near-real time measurements. In this study, we present the total refractivity and zenith total delay (ZTD) models based on a numerical weather prediction (NWP) model, Global Navigation Satellite System (GNSS) data and ground-based meteorological observations. We reconstruct the total refractivity profiles over the western part of Switzerland and the total refractivity profiles as well as ZTDs over Poland using the least-squares collocation software COMEDIE (Collocation of Meteorological Data for Interpretation and Estimation of Tropospheric Pathdelays) developed at ETH Zürich. In these two case studies, profiles of the total refractivity and ZTDs are calculated from different data sets. For Switzerland, the data set with the best agreement with the reference radiosonde (RS) measurements is the combination of ground-based meteorological observations and GNSS ZTDs. Introducing the horizontal gradients does not improve the vertical interpolation, and results in slightly larger biases and standard deviations. For Poland, the data set based on meteorological parameters from the NWP Weather Research and Forecasting (WRF) model and from a combination of the NWP model and GNSS ZTDs shows the best agreement with the reference RS data. In terms of ZTD, the combined NWP-GNSS observations and GNSS-only data set exhibit the best accuracy with an average bias (from all stations) of 3.7 mm and average standard deviations of 17.0 mm w.r.t. the reference GNSS stations.ISSN:0949-7714ISSN:1432-139

Tropospheric refractivity and zenith path delays from least-squares collocation of meteorological and GNSS data

Precise positioning requires an accurate a priori troposphere model to enhance the solution quality. Several empirical models are available, but they may not properly characterize the state of troposphere, especially in severe weather conditions. Another possible solution is to use regional troposphere models based on real-time or near-real time measurements. In this study, we present the total refractivity and zenith total delay (ZTD) models based on a numerical weather prediction (NWP) model, Global Navigation Satellite System (GNSS) data and ground-based meteorological observations. We reconstruct the total refractivity profiles over the western part of Switzerland and the total refractivity profiles as well as ZTDs over Poland using the least-squares collocation software COMEDIE (Collocation of Meteorological Data for Interpretation and Estimation of Tropospheric Pathdelays) developed at ETH Zürich. In these two case studies, profiles of the total refractivity and ZTDs are calculated from different data sets. For Switzerland, the data set with the best agreement with the reference radiosonde (RS) measurements is the combination of ground-based meteorological observations and GNSS ZTDs. Introducing the horizontal gradients does not improve the vertical interpolation, and results in slightly larger biases and standard deviations. For Poland, the data set based on meteorological parameters from the NWP Weather Research and Forecasting (WRF) model and from a combination of the NWP model and GNSS ZTDs shows the best agreement with the reference RS data. In terms of ZTD, the combined NWP-GNSS observations and GNSS-only data set exhibit the best accuracy with an average bias (from all stations) of 3.7 mm and average standard deviations of 17.0 mm w.r.t. the reference GNSS stations.ISSN:0949-7714ISSN:1432-139