Leibniz Universität Hannover Faculty Faculty of Civil Engineering and Geodetic Science
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Institute of Geodesy
 
Research
Research Projects
Finished Research projects

Currents Research Projects

Terrestrial Gravimetry

  • Gravimetric Tides and Gravity Currents in the North Sea
    The research group is investigating the gravity and deformation (tilt) effect caused by time variations of the mass distribution in the atmosphere and in the sea. It has to be distinguished between the direct Newtonian attraction effects and indirect loading effects. The latter part is accompanied by a vertical shift and a tilt of the sea floor as well as the land surface, especially along the coast or on islands, because of the elasticity of the solid Earth’s crust. Such a vertical ground displacement is associated with an absolute height change of the gravimeter w.r.t. the geocenter. The combined observation of gravity and tilt changes allows the separation of signals due to attraction and load deformation.
    Leaders: Dr.-Ing. Ludger Timmen, Dr. Adelheid Weise
    Team: Dr.-Ing. Ludger Timmen, Dr. Adelheid Weise
    Year: 2018
    Sponsors: IfE, Germany’s Excellence Strategy – EXC-2123 “QuantumFrontiers”
    Lifespan: 2018-2021
  • Gravimetry at Zugspitze and Wank Mountains (Bavarian Alps, Germany)
    The geodetic monitoring of variations caused by Alpine orogency and the diminishing permafrost are undertaken with gravimetric as well as geometric techniques. In addition to IfE (absolute and relative gravimetry, levelling), the Bavarian Academy of Sciences and Humanities (GNSS, levelling, relative gravimetry), the Institute of Astronomical and Physical Geodesy - Technical University of Munich (relative gravimetry) and the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences (superconducting gravimetry, GNSS permanent geodynamic observatory on the Zugspitze) are involved in the cooperation.
    Leaders: Dr.-Ing. Ludger Timmen
    Year: 2018
    Sponsors: IFE, Germany’s Excellence Strategy – EXC-2123 “QuantumFrontiers”, GFZ Potsdam, TU München, Bayerische Akademie der Wissenschaften
  • Gravimetric reference network for a 10m atom interferometer
    The Very Long Baseline Atom Interferometer (VLBAI) at the Hannover Institute for Technology (HITec) is a physics instrument in which experiments on the interferometry of atoms can be carried out over a free-fall distance of about 10m. These experiments are mainly used for fundamental physics, but gravimetric measurements can also be performed. Due to the large fall distance and the resulting long fall time of the atoms, a future accuracy in the range of 1 nm/s² is anticipated. With classical transportable absolute gravimeters, however, some tens nm/s² are achieved. The VLBAI could therefore be a reference for classical gravimeters. For these experiments and for the evaluation of the error budget, however, knowledge of the local gravitational field is necessary. This will be determined in parallel to the installation of the large-scale instrument and further on by gravimetric measurements and forward modelling.
    Leaders: Dr.-Ing. Manuel Schilling, Dr.-Ing. Ludger Timmen
    Team: Dr.-Ing. Manuel Schilling, Dr.-Ing. Ludger Timmen
    Year: 2017
    Sponsors: IfE, SFB-1128, EXC-2123 "QuantumFrontiers"
    Lifespan: 2017-2025
    © M. Schilling
  • A mobile absolute gravimeter based on atom interferometry for highly accurate point observations
    Atom interferometers have demonstrated a high sensitivity to inertial forces. The Gravimetric Atom Interferometer (GAIN), developed at Humboldt-Universität zu Berlin, is a mobile atom interferometer based on interfering ensembles of laser-cooled Rb-87 atoms in an atomic fountain configuration. In the continued development state-of-the-art superconductiong gravimeters and laser-interferometer based absolute gravimeters are used for comparisons with and the characterization of GAIN.
    Leaders: Prof. Dr.-Ing. Jürgen Müller
    Team: M. Sc. Manuel Schilling
    Year: 2012
    Sponsors: DFG
    © IFE / M. Schilling

Gravity Field and Geoid Modelling

  • COST-G: International Combination Service for Time-variable Gravity Field Solutions
    COST-G ist ein zukünftiges Produktzentrum des IGFS (International Gravity Field Service), welches das Ziel hat kombinierte monatliche Schwerefelder bereitzustellen. Hierbei werden die von den einzelnen Analysezentren berechneten Normalgleichungsmatrizen der Schwerefeldparameter aufbauend auf eigens für den Service definierten Qualitätsmerkmalen empirisch gewichtet, gelöst und validiert.
    Leaders: Prof. Jakob Flury
    Team: M.Sc. Igor Koch
    Year: 2019
  • Europäische Geoidberechnungen
    Leaders: Dr.-Ing. Heiner Denker
    Team: Dr.-Ing. Heiner Denker
    Year: 2019
    Sponsors: verschiedene Landes- und Drittmittel; Unterstützung durch Internationale Assoziation für Geodäsie (IAG)
    Lifespan: seit 1990
  • QuantumFrontiers (EXC2123) / Research Unit Relativistic Geodesy
    Leaders: Prof. Dr. Karsten Danzmann (AEI), Prof. Dr. Claus Lämmerzahl (ZARM)
    Team: Dr.-Ing. Heiner Denker u. a.
    Year: 2019
    Sponsors: Deutsche Forschungsgemeinschaft (DFG)
  • Gravity field recovery from satellite-to-satellite tracking data
    Das Institut für Erdmessung berechnet und publiziert globale monatliche Schwerefelder aus Sensordaten der Multisatellitenmission GRACE. Zentrale Aspekte der Schwerefeldbestimmung und Forschungsgegenstand dieses Projektes sind die Sensorfusion, die Modellierung von konservativen und nicht-konservativen Störkräften, die numerische Integration der Satellitenbewegung, die Anpassung von modellierten Satellitenbahnen an Beobachtungen durch iterative Schätzverfahren, sowie die Parametrisierung der Satellitenbewegung.
    Leaders: Prof. Jakob Flury
    Team: M.Sc. Igor Koch
    Year: 2018
    © IfE / I. Koch
  • German Combined Geoid 2016 (GCG2016)
    Leaders: Dr.-Ing. Heiner Denker
    Team: Dr.-Ing. Heiner Denker
    Year: 2016
  • High-resolution modeling of geoid-quasigeoid separation
    Leaders: Prof. Dr.-Ing. Jakob Flury
    Year: 2013

Relativistic Geodesy

  • Chronometrisches Nivellement
    Leaders: Dr.-Ing. Heiner Denker
    Team: Dr.-Ing. Heiner Denker und weitere Mitarbeiter
    Year: 2019
    Sponsors: verschiedene Landes- und Drittmittel sowie separate Projekte
    Lifespan: seit 2010
  • High-performance clock networks and their application in geodesy
    The rapid development of optical clocks and frequency transfer techniques provides the opportunity to compare clocks’ frequencies at the uncertainty level of 10-18. This will enable relativistic geodesy with the aimed accuracy of cm in terms of height. Clock networks are thus highly relevant to various geodetic applications, such as the realization of a height reference system and the determination of regional/global gravity fields. In this project, we aim to investigate the potential of high-performance clock networks and quantify their contributions to specific applications through dedicated simulations.
    Leaders: Prof. Dr.-Ing. Jürgen Müller
    Team: Dr.-Ing. Hu Wu
    Year: 2019
    Sponsors: Germany’s Excellence Strategy – EXC-2123 “QuantumFrontiers” (DFG)
  • LLR Relativity Test
    Leaders: Prof. Dr.-Ing. habil. Jürgen Müller
    Team: Dr.-Ing. Liliane Biskupek
    Year: 2019
    Sponsors: DFG
  • Relativistische Geodäsie in Netzen optischer Atomuhren
    Leaders: Prof. Dr.-Ing. Jakob Flury
    Year: 2018
    Lifespan: seit 2018

Satellite Gravimetry

  • 3D Earth – A Dynamic Living Planet
    The goal of 3D-Earth is to establish a global 3D reference model of the crust and upper mantle based on the analysis of satellite gravity e.g. GOCE and (electro-)magnetic missions e.g. Swarm in combination with seismological models and analyse the feedback between processes in Earth’s deep mantle and the lithosphere. Selected case examples will provide the possibility to test these approaches on a global and regional scale. This will result in a framework for consistent models that will be used to link the crust and upper mantle to the dynamic mantle.
    Leaders: Prof. Dr.-Ing. Jakob Flury
    Team: Dr.-Ing. Akbar Shabanloui
    Year: 2017
    Sponsors: ESA
    Lifespan: 2017-2019
  • Earth System Mass Transport Mission (e.motion)
    Leaders: Jakob Flury
    Year: 2013

Antenna Calibration

  • GPS Codephasen-Variationen für GNSS-Empfangsantennen
    Neben der sehr gut bekannten Existenz von Abweichungen des Empfangszentrums von GNSS-Antennen für Trägerphasen sind gleiche Effekte auch auf der Codephase (Code Phase Variations CPV) gefunden worden. Diese Abweichungen sind stark von der Beschaffenheit und Qualität der Empfangsantennen abhängig und nehmen gerade bei Massenmarktprodukten erhebliche Abweichungen an. Der Nachweis über die Charaktersitik der Codephasen-Variationen ist besonders für Navigationsanwendungen wichtig, da zum einen die Antennen notwendigen Spezifikationen entsprechen müssen und zum anderen die Präzision des Sensors durch Berücksichtigung dieser individuellen Kalibrierwerte deutlich verberssert werden können.
    Leaders: Dr.-Ing. Tobias Kersten
    Team: Yannick Breva, Johannes Kröger
    Year: 2018
  • Trägerphasenvariationen (PCC) für neue GNSS-Signale
    Trägerphasenvaritionen sind überaus notwendig für die präzise GNSS-Navigation und Positionierung. Derzeit werden nur GPS L1/L2 und GLONASS L1/L2 im Rahmen der operationellen roboterbasierten Kalibierung zur Verfügung gestellt. Die Weiterentwicklung der individuellen Satellitensysteme (GPS, GLONASS) und die Entwicklung von neuen Systemen (Galileo, Beidou) erfordern die Weiterentwicklung des Kalibrierverfahrens zur Bestimmung entsprechender Parameter neuer Systeme und Frequenzen. Ziel des Projektes ist die Bereitstellung und konsistente Verarbeitung von Kalibrierwerten für GPS L5 und Galileo E1/E5 Signalen auf Basis von Kugelfunktionsentwicklungen. Erhobene Phasenpattern werden mit Kalibrierwerten anderer Institutionen vergleichen und koordiniert ausgetauscht.
    Leaders: Dr.-Ing. Tobias Kersten
    Team: Johannes Kröger, Yannick Breva
    Year: 2018

GNSS and Inertial Navigation

  • Correction of GNSS multipath effects for reliable autonomous localisation of highly automated vehicles in metropolitan areas (KOMET)
    The code range (code measurement) used in automotive applications often cannot provide the required resolution of the location due to the high measurement noise. The complex GNSS signal propagation (signal shading, multipath effects) in urban environments makes the determination of an accurate and robust positioning solution a particularly challenging task - e.g. for positioning in narrow street canyons. The research project aims to develop and implement innovative correction methods to reduce multipath effects in order to improve carrier phase-based GNSS positioning.
    Leaders: Prof. Dr.-Ing. Steffen Schön, Dr.-Ing. Tobias Kersten
    Team: Dr.-Ing. Tobias Kersten, M.Sc. Fabian Ruwisch
    Year: 2020
    Sponsors: BMWi / TÜV Rheinland Consulting GmbH
    © Ch. Skupin (Bosch)
  • Bounding and propagating observation uncertainty with interval mathematic (GRK 2159)
    Intervals (Jaulin et al 2001) can be seen as a natural way to bound observation uncertainty in navigation systems such as GPS, IMU or optical sensors like LIDAR, since they are in principle free of any assumption about probability distributions and can thus describe adequately remaining systematic effects (Schön 2016, Schön and Kutterer 2006). In this project, we intent to experimentally investigate in more details the actual size of observation intervals.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: Jingyao Su, M.Sc.
    Year: 2020
    Sponsors: DFG
  • Collaborative Navigation for Smart Cities (GRK 2159)
    Global Navigation Satellite Systems (GNSS) is the only navigation sensor that provides absolute positioning. However, urban areas form the most challenging environment for GNSS to achieve a reliable position. Because of the reduced satellite visibility and disturbed signal propagation like diffraction and multipath, the resulting position has a reduced accuracy and availability. The overall research objective of this project is to reduce these shortcomings through collaboration. Therefore, similarity of multipath at different locations within streets will be studied.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: Lucy Icking, M.Sc.
    Year: 2019
    Sponsors: DFG
  • QGyro: Quantum Optics Inertial Sensor Research
    The objective of this research programme is to develop and test high-precision quantum inertial sensors that support conventional inertial navigation sensors in order to expand these sensors to up to 6 degrees of freedom and use them for autonomous navigation in various further development stages.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: M.Sc. Benjamin Tennstedt, Dr.-Ing. Tobias Kersten
    Year: 2019
    Sponsors: BMWi | German Aerospace Centre (DLR) - 50RK1957
    Lifespan: 2019 - 2022
  • Entwicklung und Test einer für Quantensensoren adäquaten Berechnungsstrategie für die Inertialnavigation
    Durch neue Messprinzipien haben Quantensensoren signifikante Verbesserungen in Stabilität und Genauigkeit bei der Erfassung von inertialen Einflüssen erzielt. Anstelle mechanischer Federsysteme in Beschleunigungsmessern oder durch einen Faserkreisel oder Ringresonator umschlossene Flächen in Lasergyroskopen sind in Quantensensoren die Skalenfaktoren an atomare Übergänge gebunden und auf Frequenzmessungen zurückzuführen. Die alternativen Messverfahren und hohen Sensitivitäten der Quantensensoren erfordern eine adäquate Auswertestrategie, die sich von der klassischen Herangehensweise der Inertialnavigation unterscheidet. Ziel der Studie ist die Entwicklung und der Test einer entsprechenden Berechnungsstrategie, die gezielt die Anwendbarkeit der einzelnen Berechnungsschritte bei der Quanteninertialnavigation überprüft, und geeignete Alternativen, beispielsweise bei der Integrationsdynamik oder geschätzten Systemparametern, vorschlägt.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: M.Sc. Benjamin Tennstedt
    Year: 2018
    Sponsors: DLR
  • VeNaDU 2: Verbesserte Positionierung und Navigation durch Uhrmodellierung
    Dieses Folgeprojekt zum Vorhaben VeNaDU untersucht zum einen den Performance-Gewinn durch den Einsatz hochstabiler Atomuhren in kinematischem PPP. Zum anderen soll eine Hardware-technische Umsetzung einer miniaturisierten Atomuhr in einem Einfrequenz-Empfänger realisiert werden.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: Dr.-Ing. Thomas Krawinkel, Dr. Ankit Jain
    Year: 2017
  • Alternative Integrity Measures Based on Interval Mathematics (GRK 2159, Topic 1)
    This project deals with the development of alternative integrity measures based on interval mathematic, fuzzy theory and imprecise random variables.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: M.Sc. Hani Dbouk
    Year: 2016
    Sponsors: DFG
  • Optimal Collaborative Positioning (GRK 2159, Topic 4)
    Collaborative Positioning (CP) is a promising technique in which a group of dynamic nodes (pedestrians, vehicles, etc.) equipped with different (time synchronized) sensors can increase the quality of the Positioning, Navigation and Timing (PNT) information by exchanging navigation information as well as performing measurements between nodes or to elements of the environment (urban furniture, buildings, etc.).
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: M.Sc. Nicolas Garcia Fernandez
    Year: 2016
    Sponsors: DFG
  • Improved GPS data analysis for the Swarm constellation
    New concepts for GPS observation data quality assessment and positioning should be developed and evaluated taking advantage of variable geometries in the Swarm constellation.
    Leaders: Prof. Dr.-Ing. Steffen Schön
    Team: Dipl.-Ing. Le Ren
    Year: 2015
    Sponsors: DFG

Lunar Laser Ranging (LLR)

  • LLR Relativity Test
    Leaders: Prof. Dr.-Ing. habil. Jürgen Müller
    Team: Dr.-Ing. Liliane Biskupek
    Year: 2019
    Sponsors: DFG

CRC 1128 (geo-Q)

  • Gravimetric reference network for a 10m atom interferometer
    The Very Long Baseline Atom Interferometer (VLBAI) at the Hannover Institute for Technology (HITec) is a physics instrument in which experiments on the interferometry of atoms can be carried out over a free-fall distance of about 10m. These experiments are mainly used for fundamental physics, but gravimetric measurements can also be performed. Due to the large fall distance and the resulting long fall time of the atoms, a future accuracy in the range of 1 nm/s² is anticipated. With classical transportable absolute gravimeters, however, some tens nm/s² are achieved. The VLBAI could therefore be a reference for classical gravimeters. For these experiments and for the evaluation of the error budget, however, knowledge of the local gravitational field is necessary. This will be determined in parallel to the installation of the large-scale instrument and further on by gravimetric measurements and forward modelling.
    Leaders: Dr.-Ing. Manuel Schilling, Dr.-Ing. Ludger Timmen
    Team: Dr.-Ing. Manuel Schilling, Dr.-Ing. Ludger Timmen
    Year: 2017
    Sponsors: IfE, SFB-1128, EXC-2123 "QuantumFrontiers"
    Lifespan: 2017-2025
    © M. Schilling

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Space Sensor Technologies

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