Abstract The multiconstellation Global Navigation Satellite Systems (GNSS) (e.g., GPS, GLObal NAvigation System (GLONASS), Galileo, and BeiDou) offers great opportunities for real‐time retrieval of atmospheric parameters supporting numerical weather prediction nowcasting or severe event monitoring. In this study, the observations from different GNSS are combined to retrieve based on precise point positioning technique. parameters, retrieved multi‐GNSS a 180 day period about 100 globally...

The precision of sea surface altimetry using bistatically reflected signals the Global Navigation Satellite System (GNSS) is typically one to two orders magnitude worse than dedicated radar altimeters. However, when scattering coherent, electromagnetic phase carrier signal can be tracked, providing precise ranging measurements. Under grazing angle (GA) geometries, conditions for coherent are maximized, enabling phase-delay altimetric techniques over waters. This work presents first...

Abstract Radio signals transmitted by Global Navigation Satellite System (GNSS) satellites experience tropospheric delays. While the hydrostatic part, referred to as zenith delay (ZHD) when mapped direction, can be analytically modelled with sufficient accuracy, wet (ZWD), is much more difficult determine and needs estimated. Thus, there exist several ZWD models which are used for various applications such positioning climate research. In this study, we present a data-driven, global model of...

A comparison campaign to evaluate and compare troposphere delays from different ray-tracing software was carried out under the umbrella of International Association Geodesy Working Group 4.3.3 in first half 2010 with five institutions participating: GFZ German Research Centre for Geosciences (GFZ), Groupe de Recherche Geodesie Spatiale, National Institute Information Communications Technology (NICT), University New Brunswick, Geophysics Vienna Technology. High-resolution data operational...

Abstract. Initial objectives and design of the Benchmark campaign organized within European COST Action ES1206 (2013–2017) are described in paper. This has aimed to support development validation advanced Global Navigation Satellite System (GNSS) tropospheric products, particular high-resolution ultra-fast zenith total delays (ZTDs) gradients derived from a dense permanent network. A complex data set was collected for 8-week period when several extreme heavy precipitation episodes occurred...

In a previous study we developed an elegant technique to compute the signal travel time delay due neutral atmosphere, also known as slant total (STD), between Global Positioning System (GPS) satellite and ground‐based receiver utilizing data from numerical weather model (NWM). Currently, make use of NWM Forecast (GFS) because short‐range forecasts are easily accessible. this introduce some modifications which double speed our algorithm without altering its precision; on ordinary PC (using...

Abstract. An extensive validation of line-of-sight tropospheric slant total delays (STD) from Global Navigation Satellite Systems (GNSS), ray tracing in numerical weather prediction model (NWM) fields and microwave water vapour radiometer (WVR) is presented. Ten GNSS reference stations, including collocated sites, almost 2 months data 2013, severe events were used for comparison. Seven institutions delivered their STDs based on observations processed using 5 software programs 11 strategies...

Abstract Precipitable water vapor (PWV) is an important parameter for climate research and a crucial factor to achieve high accuracy in satellite geodesy altimetry. Currently Global Navigation Satellite System (GNSS) PWV retrieval using static Precise Point Positioning limited ground stations. We demonstrated the kinematic method with shipborne GNSS observations during 20‐day experiment 2016 Fram Strait, region of Arctic Ocean between Greenland Svalbard. The shows agreement ~1.1 mm numerical...

A numerical algorithm based on Fermat's Principle was developed to simulate the propagation of Global Positioning System (GPS) radio signals in refractivity field a weather model. The unique proposed is that ray‐trajectory automatically involves location ground‐based receiver and satellite, i.e. posed two‐point boundary value problem solved by an implicit finite difference scheme. This feature allows fast accurate computation signal travel‐time delay, referred as Slant Total Delay (STD),...

Abstract In this study, we estimate integrated water vapor (IWV) trends from very long baseline interferometry (VLBI) and global navigation satellite systems (GNSS) data analysis, as well numerical weather models (NWMs). We study the impact of modeling parameterization tropospheric delay VLBI on IWV trends. address meteorological source utilized to model hydrostatic thermal deformation antennas, mapping functions employed project zenith delays arbitrary directions. To do so, derive a new...

Abstract. The recent dramatic development of multi-GNSS (Global Navigation Satellite System) constellations brings great opportunities and potential for more enhanced precise positioning, navigation, timing, other applications. Significant improvement on positioning accuracy, reliability, as well convergence time with the fusion can be observed in comparison single-system processing like GPS Positioning System). In this study, we develop a numerical weather model (NWM)-constrained point...

Abstract The developing multi‐Global Navigation Satellite Systems (GNSS) constellations have the potential to provide accurate high‐resolution tropospheric gradients. Such data, closely linked strong humidity gradients accompanying severe weather phenomena, are considered a new important data source for meteorological studies, e.g., nowcasting of rainfall events. Here we describe development multi‐GNSS processing system precise retrieval retrieved products were validated by using independent...

Abstract For more than two decades, Global Positioning System (GPS) tropospheric delays have successfully been exploited to monitor the water vapor in near real time and reprocessing mode. Although reprocessed data are considered reliable for climatic research, it is important address often present gaps, inhomogeneities, use a proper model describe stochastic part of series so that trustworthy trends estimated. Having relatively long series, daily Zenith Total Delay, precipitable (PWV),...

This paper presents a simulation study on Global Navigation Satellite System (GNSS) reflections focusing phase altimetric method for ocean topography retrieval. It examines carrier residuals of Earth-reflected GNSS signals in preparation the Reflectometry Radio Occultation and Scatterometry experiment aboard International Space Station (GEROS-ISS). The residuals' sensitivity to (maximum 2-m amplitude variation global sea level) is shown. A trigonometric approach determine specular reflection...

Abstract Accurate tropospheric delays from Numerical Weather Models (NWM) are an important input to space geodetic techniques, especially for precise real‐time Global Navigation Satellite Systems, which indispensable earthquake and tsunami early warning systems as well weather forecasting. The NWM‐based currently provided either site‐specific with a limited spatial coverage, or on two‐dimensional grids close the Earth surface, cannot be used high altitudes. We introduce new method of...

Abstract Storms and floods are the most frequent natural disaster in western central Europe. Due to climate change, intensive storms with prolonged rain episodes will continue cause even more destructive flooding. The good understanding forecasting of such events thus uttermost importance. One ways improve weather forecasts is assimilation external data, as global navigation satellite systems (GNSS). In this study, a preparation multi-GNSS tropospheric products—zenith total delays, gradients...

Abstract. An analysis of processing settings impacts on estimated tropospheric gradients is presented. The study based the benchmark data set collected within COST GNSS4SWEC action with observations from 430 Global Navigation Satellite Systems (GNSS) reference stations in central Europe for May and June 2013. Tropospheric were eight different variants GNSS using precise point positioning (PPP) G-Nut/Tefnut software. gradient mapping function, elevation cut-off angle, constellation,...

The Benchmark data set collected within the European COST Action ES1206 has aimed to support development and validation of advanced Global Navigation Satellite System (GNSS) tropospheric products, in particular high-resolution zenith delays gradients. In this work we utilize unique show that interpolation GNSS Zenith Wet Delays (ZWDs) can be improved by utilizing To do first prove concept with simulated observations, is, gradients derived from a Numerical Weather Model. We how converted ZWD...

Abstract. The assimilation of Global Navigation Satellite System (GNSS) zenith total delays (ZTDs) into numerical weather models improves forecasts. In addition, the GNSS tropospheric gradient (TG) estimates provide valuable insight moisture distribution in lower troposphere. this study, we utilize a newly developed forward operator for TGs to investigate sensitivity effects incorporating Weather Research and Forecasting model at varying station network densities. We assimilated ZTD from...

The Global Navigation Satellite System (GNSS) tropospheric gradients offer valuable information about how moisture is distributed in the atmosphere. These are determined by studying variations atmosphere refracts signals, which measured based on delays from satellites positioned at different angles. Zus et al. (2023) developed a gradient operator that has been added to Weather Research and Forecasting (WRF) model. Thundathil (2024) conducted several impact experiments showing promising...

The Passive REflecTometry and dosimeTrY (PRETTY) satellite has been launched into a low Earth orbit, of about 570 km altitude, on 9th October 2023. Its main payload is dedicated to reflectometry using signals Global Navigation Satellite Systems (GNSS). on-board receiver provides delay maps the Earth-reflected signal. objective mission exploit for ocean sea ice altimetry.Observations are recorded in grazing angle geometry. It means that incident reflected ray reach maximum elevation at...