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

QUEST

• Earth System Mass Transport Mission (e.motion)

  Leaders: Jakob Flury

  Year: 2013

Space Sensor Technologies

• Modellierung mit Quantensensoren gestützter Satellitenmissionen

  Dieses Projekt beschreibt den den Einsatz von Beschleunigungsmessern auf Grundlage von Atominterferometern in Schwerefeldsatellitenmissionen. Es wird sowohl der Ersatz klassischer elektrostatischer Beschleunigungsmesser durch Quantensensoren als auch die Kombination beider Sensorarten in einem Hybridsystem untersucht.

  Leaders: Prof. Dr.-Ing. Jürgen Müller

  Team: M.Sc. Annike Knabe, Dr.-Ing. Hu Wu, Dr.-Ing. Manuel Schilling

  Year: 2019

  Sponsors: DLR

  © Schilling
• Interactions of Low-orbiting Satellites with the Surrounding Ionosphere and Thermosphere Part II (INSIGHT II)

  At our Institute, we provide reduced and calibrated Swarm accelerometer data for the ESA Swarm data processing chain that are the basis for the determination of thermospheric density. This includes the accelerometer calibration by precise orbit determination of Swarm satellites.

  Leaders: Prof. Dr.-Ing. Jakob Flury

  Team: Dr.-Ing. Akbar Shabanloui

  Year: 2018

  Sponsors: DFG

  Lifespan: 2018-2021
• Swarm ESL/DISC: Support to accelerometer data analysis and processing

  Leaders: Prof. Dr.-Ing. Jakob Flury

  Team: Dr.-Ing. Sergiy Svitlov, Dr.-Ing. Akbar Shabanloui

  Year: 2016

  Sponsors: ESA (DTU Space)

  Lifespan: 2016-2020