A5044188094- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Geomagnetism and Paleomagnetism Studies
- Advanced Frequency and Time Standards
- Geophysical and Geoelectrical Methods
- Historical Geography and Cartography
- Inertial Sensor and Navigation
- Atomic and Subatomic Physics Research
- Scientific Measurement and Uncertainty Evaluation
- Cardiovascular Syncope and Autonomic Disorders
- Cold Atom Physics and Bose-Einstein Condensates
- Methane Hydrates and Related Phenomena
- Geological Modeling and Analysis
- Geodetic Measurements and Engineering Structures
- Computational Physics and Python Applications
- Soil Geostatistics and Mapping
- Seismic Imaging and Inversion Techniques
- Geological Formations and Processes Exploration
- Geology and Paleoclimatology Research
- Statistical and numerical algorithms
- Geological and Geophysical Studies
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Geographic Information Systems Studies
- earthquake and tectonic studies
Leibniz University Hannover
2013-2024
The Ohio State University
1990
TÜV Nord (Germany)
1989
Abstract Leveraging the unrivalled performance of optical clocks as key tools for geo-science, astronomy and fundamental physics beyond standard model requires comparing frequency distant faithfully. Here, we report on comparison agreement two strontium at an uncertainty 5 × 10 −17 via a newly established phase-coherent link connecting Paris Braunschweig using 1,415 km telecom fibre. The remote is limited only by instability lattice themselves, with negligible contributions from transfer. A...
We review experimental progress on optical atomic clocks and frequency transfer, consider the prospects of using these technologies for geodetic measurements. Today, standards have reached relative inaccuracies below 10-17, opening new fields fundamental applied research. The dependence frequencies gravitational potential makes ideal candidates search deviations in predictions Einstein's general relativity, tests modern unifying theories development gravity field sensors. In this review, we...
We report on the first comparison of distant caesium fountain primary frequency standards (PFSs) via an optical fiber link. The 1415 km long link connects two PFSs at LNE-SYRTE (Laboratoire National de métrologie et d'Essais—SYstème Références Temps-Espace) in Paris (France) with PTB (Physikalisch-Technische Bundesanstalt) Braunschweig (Germany). For a time, these have been major contributors to accuracy International Atomic Time (TAI), stated accuracies around . They also references for...
We have measured the geopotential difference between two locations separated by 457 km comparison of optical lattice clocks via an interferometric fiber link, utilizing gravitational redshift clock transition frequency. The <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><a:msup><a:mi/><a:mn>87</a:mn></a:msup><a:mi>Sr</a:mi></a:math> been compared side-by-side before and after one was moved to remote location. chronometrically <d:math...
The latest generation of optical atomic clocks is approaching the level one part in 1018 terms frequency stability and uncertainty. For clock comparisons definition international time scales, a relativistic redshift effect frequencies has to be taken into account at corresponding uncertainty about 0.1 m2 s−2 0.01 m gravity potential height, respectively. Besides predominant static potential, temporal variations must considered order avoid systematic shifts. Time-variable components induced...
The first year of the Geosat Exact Repeat Mission has been analyzed to obtain improved orbits, gravity model, and representation sea surface topography. starting point for this study were original geophysical data records merged with orbits by Haines et. al. (1990) computed GEM‐T1 model. A radial orbit error model following development Engelis (1987 a ) was modified account resonant effects above degree 36. Twenty‐four 17‐day arcs analyzed. Separate single 1‐year solution spherical harmonic...
Abstract We present an accurate method for the calculation of gravitational potential (GP), vector (GV), and gradient tensor (GGT) a tesseroid, considering density model in form polynomial up to cubic order along vertical direction. The solves volume integral equations effects due tesseroid by Gauss–Legendre quadrature rule. A two-dimensional adaptive subdivision technique, which automatically divides tesseroids near computation point into smaller elements, is applied improve computational...