A5070618117- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Ionosphere and magnetosphere dynamics
- Radio Astronomy Observations and Technology
- Astronomical Observations and Instrumentation
- Inertial Sensor and Navigation
- Advanced Frequency and Time Standards
- Meteorological Phenomena and Simulations
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Precipitation Measurement and Analysis
- Geophysics and Sensor Technology
- Surface Roughness and Optical Measurements
- Radio Wave Propagation Studies
- Astronomy and Astrophysical Research
- Oceanographic and Atmospheric Processes
- Calibration and Measurement Techniques
- Statistical and numerical algorithms
- Climate variability and models
- Advanced Measurement and Metrology Techniques
- Medical Imaging Techniques and Applications
- Labour Market and Migration
- Soil Moisture and Remote Sensing
- History and advancements in chemistry
- Seismic Waves and Analysis
TU Wien
2015-2024
Klinikum Passau
2024
University of Cologne
2021
Centre National de la Recherche Scientifique
2018-2020
Université Côte d'Azur
2018-2020
Institut de Physique de Nice
2020
InfraTec (Germany)
2019
Technische Universität Berlin
2018
TU Dresden
2011-2014
Nanjing Library
2013
Up to now, state-of-the-art empirical slant delay modeling for processing observations from radio space geodetic techniques has been provided by a combination of two models. These are GPT (Global Pressure and Temperature) GMF Mapping Function), both operating on the basis long-term averages surface values numerical weather Weaknesses in GPT/GMF, specifically their limited spatial temporal variability, largely eradicated new, combined model GPT2, which provides pressure, temperature, lapse...
Incorrect modeling of troposphere delays is one the major error sources for space geodetic techniques such as Global Navigation Satellite Systems (GNSS) or Very Long Baseline Interferometry (VLBI). Over years, many approaches have been devised which aim at mapping delay radio waves from zenith direction down to observed elevation angle, so-called functions. This paper contains a new approach intended refine currently most important discrete function, Vienna Mapping Functions 1 (VMF1),...
Global pressure and temperature 2 wet (GPT2w) is an empirical troposphere delay model providing the mean values plus annual semiannual amplitudes of pressure, its lapse rate, water vapor decrease factor, weighted temperature, as well hydrostatic mapping function coefficients Vienna 1. All climatological parameters have been derived consistently from monthly level data ERA-Interim fields (European Centre for Medium-Range Weather Forecasts Re-Analysis) with a horizontal resolution 1°, suitable...
Abstract Improving and homogenizing time space reference systems on Earth and, more specifically, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1 mm a long-term stability 0.1 mm/year are relevant for many scientific societal endeavors. The knowledge TRF is fundamental navigation sciences. For instance, quantifying sea level change strongly depends accurate determination geocenter motion but also positions continental island stations, such as those located at tide...
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...
The Vienna VLBI and Satellite Software (VieVS) is state-of-the-art Very Long Baseline Interferometry (VLBI) analysis software for geodesy astrometry. VieVS has been developed at Technische Universität Wien (TU Wien) since 2008, where it used research purposes teaching space geodetic techniques. In the past decade, successfully applied on observations determination of celestial terrestrial reference frames as well estimation pole offsets, universal Time (UT1-UTC), polar motion based...
A new realization of the International Celestial Reference Frame (ICRF) is presented based on work achieved by a working group Astronomical Union (IAU) mandated for this purpose. This follows initial ICRF completed in 1997 and its successor, ICRF2, adopted as replacement 2009. The frame, referred to ICRF3, nearly 40 years data acquired very long baseline interferometry at standard geodetic astrometric radio frequencies (8.4 2.3 GHz), supplemented with collected higher (24 GHz dual-frequency...
Abstract The tropospheric delay is a major error source for space geodetic techniques, and the performance of its modeling significantly limited due to high spatiotemporal variability moisture in lower atmosphere. In this study, global zenith wet (ZWD) was realized based on surface meteorological data obtained from radiosondes Global Positioning System (GPS) radio occultation (RO) measurements through random forest (RF) backpropagation neural network (BPNN) regression analysis. further...
Missing or incorrect consideration of azimuthal asymmetry troposphere delays is a considerable error source in space geodetic techniques such as Global Navigation Satellite Systems (GNSS) Very Long Baseline Interferometry (VLBI). So-called horizontal gradients are generally utilized for modeling variations and particularly required observations at low elevation angles. Apart from estimating the within data analysis, which has become common practice techniques, there also possibility to...
The correction of tropospheric influences via so-called path delays is critical for the analysis observations from space geodetic techniques like very long baseline interferometry (VLBI). In standard VLBI analysis, a priori slant are determined using concept zenith delays, mapping functions and gradients. use ray-traced i.e., with technique ray-tracing through meteorological data numerical weather models (NWM), serves as an alternative way correcting troposphere on within analysis. presented...
Geodetic and astrometric VLBI has entered a new era with the implementation of Global Observing System (VGOS). These broadband dual linear polarization observations aim at an accuracy station coordinates 1 mm reference frame stability 0.1 mm/year. Although extended brightness distribution many radio-loud active galactic nuclei observed during geodetic sessions is resolved by interferometer, established processing chain still treats these objects as point sources. We investigate impact source...
Geodetic data analysis has traditionally relied on geophysical models and statistical methods to quantify Earth's deformation, correct for atmospheric effects, refine measurement uncertainties. However, with the increasing volume complexity of geodetic observations, machine learning (ML) may offer a better alternative modelling non-linear motions sites by capturing environmental effects providing corrections unmodelled influences.ML applications across various domains geodesy, including...
Geodetic applications depend on the precise transformation between terrestrial and celestial reference frames, which are tied by Earth Orientation Parameters (EOP). Very Long Baseline Interferometry (VLBI) is only space geodetic technique capable of observing complete set EOP, includes polar motion, UT1-UTC, pole offsets. Over past three to four years, India has been planning establishment a VLBI Global Observing System (VGOS) telescope. Thus, identifying optimal location for these antennas...
Genesis is an upcoming satellite mission by the European Space Agency (ESA) that will integrate multiple space geodetic techniques on a single at altitude of 6000 km, including dedicated Very Long Baseline Interferometry (VLBI) transmitter. This innovative, dynamic observatory aims to establish highly accurate and continuous ties, significantly enhancing accuracy stability Terrestrial Reference Frames (TRFs). Including VLBI transmitter enable observations using existing VGOS antennas...