A5051337374- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Inertial Sensor and Navigation
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Space Satellite Systems and Control
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Spacecraft Design and Technology
- Astronomical Observations and Instrumentation
- Historical Geography and Cartography
- Simulation Techniques and Applications
- Arctic and Russian Policy Studies
- Anomaly Detection Techniques and Applications
- Business Process Modeling and Analysis
- Spacecraft Dynamics and Control
- Earthquake Detection and Analysis
- Advanced Frequency and Time Standards
- Computational Physics and Python Applications
- Advanced Measurement and Metrology Techniques
- Cosmology and Gravitation Theories
- Model-Driven Software Engineering Techniques
- Radio Astronomy Observations and Technology
University of Bern
2017-2024
GFZ Helmholtz Centre for Geosciences
2024
Astronomical Institute of the Slovak Academy of Sciences
2020-2023
Center for Astrophysics Harvard & Smithsonian
2019
ESA's Gravity field and steady-state Ocean Circulation Explorer (GOCE) orbited the Earth between 2009 2013 for determination of static part Earth's gravity field. The GPS-derived precise science orbits (PSOs) were operationally generated by Astronomical Institute University Bern (AIUB). Due to a significantly improved understanding remaining artifacts after end GOCE mission (especially in gradiometry data), ESA initiated reprocessing entire Level 1b data 2018. In this framework, AIUB was...
Sentinel-3A/3B (S3A/B) satellites are equipped with a number of precise instruments dedicated to the measurement surface topography, sea and land temperatures ocean color. The high-precision orbit is guaranteed by three instruments: Global Positioning System (GPS) receiver, laser retroreflector Satellite Laser Ranging (SLR) Doppler Orbitography Radiopositioning Integrated (DORIS) antenna. In this article, we check possibility using SLR observations GPS-based reduced-dynamic orbits active...
Reconstructing the ionosphere with high precision is critical for understanding space weather and its impacts on satellite communications, navigation, radar systems. Traditionally, ionospheric studies rely ionosondes measurements as well ground based Total Electron Content derived from GNSS (Global Navigation Satellite System) local measurements, but also Radio Occultation (RO) insitu electron density Low Earth Orbiting Satellites (LEO) global measurements. While RO has been instrumental in...
Global Terrestrial Reference Frames (TRFs) are regularly provided by three International System (ITRS) combination centres (CCs) of the Earth Rotation and Systems Service (IERS), located at Institut national de l’information géographique et forestière (IGN), Jet Propulsion Laboratory (JPL) National Aeronautics Space Administration (NASA), Deutsches Geodätisches Forschungsinstitut (DGFI) Technical University Munich (TUM). All CCs use different...
CODE (Center for Orbit Determination in Europe) acts as one of the analysis centers International GNSS Service (IGS). One most important products are final series providing -- among others satellite orbits, clock corrections and station coordinates. Currently it includes GPS, GLONASS, Galileo satellites. The solution shall provide user community a direct access to IGS20 reference frame (the IGS-specific realization ITRF2020).Regarding this purpose, extension other systems, particular BDS...
The uncertainty characterisation in temporal gravity field recovery plays a crucial role for providing consistent and reliable information on mass change. We study determination from GRACE Follow-On satellite-to-satellite tracking data using the inter-satellite link of K-Band Ranging Systemand kinematic positions satellites as observations pseudo-observations, respectively. compute our solutions Least-Squares Adjustment with Celestial Mechanics Approach, where - next to orbit, accelerometer...
Since the launch of ESA Swarm satellites in 2014, GPS data has been used to monitor monthly changes Earth’s gravity field at a spatial resolution larger than 1,500 km (half-wavelength). We have chosen processing strategies that do not rely on assumptions temporal and correlations, producing models are independent GRACE GRACE-FO data. team composed Astronomical Institute University Bern, Czech Academy Sciences, Delft Technology, Geodesy Graz School Earth Sciences Ohio State...
Coronal mass ejections (CMEs) from the Sun can cause geomagnetic storms which thermosphere to expand. This leads enhanced air drag for satellites in low Earth orbit (LEO). work focuses on evaluation of orbital decay with a focus selected storm events. Using Bernese GNSS Software (BSW), reduced-dynamic orbits different LEO are computed data on-board receivers, where non-gravitational accelerations modelled by means estimated empirical piecewise-constant (PCAs). The is then calculated using...
ESA’s Genesis mission, planned to launch in 2028, aims contribute a highly improved International Terrestrial Reference Frame (ITRF) with an accuracy of 1 mm and stability 0.1 mm/year. It will combine GNSS, DORIS, SLR VLBI space geodetic techniques, acting as the first ever space-tie using these four techniques. The satellite orbit at altitude 6000 km be equipped two GNSS antennas, pointing zenith nadir direction, order counteract loss coverage those altitudes.For mission provide...
To meet the demanding requirements in terms of accuracy and availability, GPS has introduced signals on L5 that are compatible to Galileo E5a signals. The signal was designed mitigate multipath poor performance harsh environments such as indoor, forests, areas affected by jamming. As L2 will become obsolete future, action must be taken take advantage modern type which is currently broadcast 19 out satellites. This particularly important for some future LEO satellites (e.g. EPS-SG) rely...
Spire Global, Inc. operates a growing fleet of currently more than 100 CubeSats in different low Earth orbits for commercial observation. These satellites are equipped with dual-frequency GPS receivers and an attitude determination control system, allowing precise orbit determination. For three time span six months we analyze the performance quality on-board collected data employ it using Bernese GNSS Software Napeos, two independent state-of-the-art processing software packages. We describe...
Abstract Satellite laser ranging (SLR) retroreflectors along with GNSS receivers are installed onboard numerous active low earth orbiters (LEOs) for the independent validation of GNSS-based precise orbit determination (POD) products. SLR results still contain many systematic errors that require special handling various biases. For this purpose, we derive methods reducing effects affecting residuals to LEO Swarm satellites. We test solutions incorporating estimation range biases, station...
The GENESIS mission prepared for launch in 2027 integrates the four space-geodetic techniques on a single spaceborne platform medium Earth orbit. With its unique observations and alternative tie concepts, aims to contribute an improved accuracy homogeneity of future terrestrial reference system realizations. To assess expected contribution Global Navigation Satellite System (GNSS) tracking, comprehensive GNSS coverage analysis is performed based detailed link-budget simulations, taking into...
Satellites with dual-frequency Global Navigation Satellite Systems (GNSS) receivers can measure integrated electron density, known as slant Total Electron Content (sTEC), between the receiver and transmitter. Precise relative variations of sTEC are achievable using phase measurements on L1 L2 frequencies, yielding around 0.1 TECU or better.However, CubeSats like Spire LEMUR, simpler setups code noise in order several meters, face limitations absolute accuracy. Their accuracy, determined by...
Abstract. This paper discusses strategies to improve the Gravity Recovery And Climate Experiment (GRACE) monthly solutions computed at Astronomical Institute of University Bern (AIUB) which are contributing Horizon 2020 project G3P – Global Gravity-based Groundwater Product. To AIUB-GRACE gravity field solutions, we updated use Level-1B observations, adapted background models, and improved processing in terms instrument screening parameterization. We used Release 3 K-band product (KBR) star...
Abstract Satellites with dual‐frequency Global Navigation Satellite Systems (GNSS) receivers can measure integrated electron density, known as slant Total Electron Content (sTEC), between the receiver and transmitter. Precise relative variations of sTEC are achievable using phase measurements on L1 L2 frequencies, yielding an accuracy around 0.1 TECU or better. However, CubeSats like Spire LEMUR, simpler setups (e.g., patch antennas) code noise in order several meters, face limitations...
Abstract Orbit determination of probes visiting Solar System bodies is currently the main source our knowledge about their internal structure, inferred from estimate gravity field and rotational state. Nongravitational forces acting on spacecraft need to be accurately included in dynamical modeling (either explicitly or form empirical parameters) not degrade solution its geophysical interpretation. In this study, we present recovery NASA GRAIL orbits lunar solutions up degree order 350. We...
Abstract Gravity fields derived from GPS tracking of the three Swarm satellites have shown artifacts near geomagnetic equator, where carrier phase on L2 frequency is unable to follow rapid ionospheric path delay changes due a limited loop bandwidth only 0.25 Hz in early years mission. Based knowledge filter design, an analytical approach developed recover original signal observed through inversion transfer function. Precise orbit determination and gravity field solutions are used assess...
<p>The Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2) mission was launched on June 25, 2019 into six evenly spaced circular orbital planes of 24° inclination with initial altitudes 725 km. By February 2021 the COSMIC-2 satellites will be lowered to an operational altitude about 520 The carry advanced Tri‐GNSS (Global Navigation Satellite System) Radio-occultation (TGRS) instrument provide high vertical resolution...