Tobias KerstenLeibniz Universität Hannover · Institute of Geodesy
Tobias Kersten
Dr.-Ing.
About
63
Publications
12,798
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237
Citations
Introduction
Additional affiliations
December 2014 - January 2018
Position
- PostDoc Position
Description
- Geo-Monitoring, combination of GNSS, gravimetry and leveling, research data management, server maintance, founding & structuring new courses for GNSS, teaching, GNSS inland vessel navjgation, alternative navigation approaches
January 2018 - present
Position
- Research Associate
Description
- Research data management, GNSS campaigns, stochastic modeling of uncertainties, GNSS network processing, coordinating team, laboratories & equipment, GNSS antenna calibration, webpage, server and digital services
May 2009 - December 2014
Position
- Research Assistant
Description
- Working and profiling in GNSS antenna calibration, antenna metamaterials, application of GNSS antenna calibration values, teaching and supervising student, public relation of geodesy (cooperation with undergraduate schools and universities)
Publications
Publications (63)
The role of codephase center corrections (CPC), also known as group delay variations (GDV), becomes more important nowadays, e.g. in navigation applications or ambiguity resolution. CPC are antenna dependent delays of the received codephase. They are varying with the angle of arrival of the signal at the GNSS antenna, i.e. with azimuth and elevatio...
Consistent and reliable receiver antenna calibration sets are an essential prerequisite for precise geodetic reference frames. In the context of the igs3-reprocessing campaign and the realisation of a new international terrestrial reference frame (ITRF20) using multi-GNSS, receiver antenna phase centre correction (PCC) sets play a key role. However...
Precise navigation for fully autonomous driving—especially in dense urban areas—requires periodic precise position estimates. Global Navigation Satellite System (GNSS) technology has the potential to provide absolute positioning accuracy at a centimeter level. However, buildings in urban environments cause signal distortions and signal reflections—...
In high precision Global Navigation Satellite Systems (GNSS) applications, it is necessary to take phase center corrections (PCC) into account. Beside these corrections for carrier phase measurements, also corrections for the codephase are necessary, so called codephase center corrections (CPC). The CPC, also known as group delay variations, are an...
Precise values for absolute receiver antenna phase centre corrections (PCC) are one prerequisite for high-quality GNSS applications. Currently, antenna calibrations are performed by different institutes using a robot in the field or in an anechoic chamber. The differences between the antenna patterns are significant and require a sound comparison c...
For highly precise and accurate positioning and navigation with Global Navigation Satellite Systems (GNSS), it is mandatory to take phase center corrections (PCC) into account. These corrections are provided by different calibration facilities and methods. Currently, discussions in the framework of the International GNSS Service (IGS) antenna worki...
Accuracy, integrity and availability requirements are very stringent in urban navigation and autonomous driving. The GNSS sensor is the only one that provides self-localisation in a global coordinate system. The challenge ist to model non line-of-sight (NLOS) and multipath scenarios in urban areas. To meeth the high accuracy requirements, these dis...
This paper addresses an approach to assess the impact of phase centre correction errors of selected receiving antennas in the Polish ASG-Eupos network using GNSS processing strategies such as zero differencing and double differencing. The objective is to characterise the nature of the error patterns of GNSS receiver antennas and to understand their...
Multi-frequency and multi-constellation GNSS have the potential to boost the overall performance of GNSS-based positioning, navigation and timing. This has an impact on the realisation of global reference frames, geophysical monitoring applications as well as enabling new applications. To this end, all error sources should be adequately corrected f...
Global Navigation Satellite Systems (GNSS) are not only widely used for precise positioning, navigation and timing but also for establishing of terrestrial reference frames for geospatial applications, such as land and water management. The quality of GNSS carrier phase measurements depends on the knowledge about the location of the exact electrica...
In absolute positioning approaches, e.g. Precise Point Positioning (PPP), antenna phase center corrections (PCC) have to be taking into account. Beside PCC for carrier phase measurements, also codephase center corrections (CPC) exist, which are antenna dependent delays of the code. The CPC can be split into a codephase center offset (PCO) and codep...
Various GNSS applications require low-cost, small-scale, lightweight and power-saving GNSS devices and require high precision in terms of low noise for carrier phase and code observations. Applications vary from navigation approaches to positioning in geo-monitoring units up to integration in multi-sensor-systems. For highest precision, only GNSS r...
Für hochpräzise GNSS-Anwendungen sind Trägerphasenmessungen unabdingbar. Bei solchen Messungen ist es notwendig die individuellen Antennenphasenzentrumskorrekturen (PCC) zu berücksichtigen. Ähnliche Korrekturen existieren auch für Codebeobachtungen, so genannte Codephasenvariationen (CPV). Diese sind antennenabhängige Verzögerungen der empfangenen...
GNSS are widely used for positioning, navigation and timing (PVT). The quality of results depends on the antenna in use and the capability to take antenna specific effects into account. The most prominent corrections are the direction dependent phase center corrections (PCC), which include corrections for the phase center offset (PCO) and the phase...
Besides antenna phase center corrections (PCC) for carrier phase measurements, which have to be considered for precise GNSS application, also codephase variations (CPV) exist. These are antenna dependent delays of the code which vary with azimuth and elevation. Such variations are not provided operationally in the antenna exchange format (ANTEX) at...
Das Verbundprojekt SIMULTAN erforscht die Früherkennung für Instabilität, Unruhe und Kollaps von Erdfällen. Der neuartige Forschungsansatz kombiniert strukturelle, geophysikalische, petrophysikalische und hydrologische Kartierungsmethoden, die von Sensorentwicklung und mulit-skaliger Überwachung flankiert werden, und umfasst eine Informationsplattf...
This data set contains the raw data bundle of all gnss campaigns carried out in the years between autumn 2015 unti autumn 2017. Campaigns were measured semi annual and summarized in technical reports, which are elements of this data set. The campaings are captured under urban conditions and contain a lot of cycle slips and multipath. The aim of the...
The Institut für Erdmessung (IfE) at the Leibniz University Hannover calibrates GNSS antennas determined by the well known robot based concept in the field. Our group has recently improved the calibration procedure to support absolute receiver antenna calibrations for all GNSS frequencies (GPS L1/L2/L5, GLONASS L1/L2 and Galileo E1/E5). To fully us...
This zip package contains two files, with Phase Center Corrections (PCC) for receiver antennas in the ANTEX format for the following frequencies: GPS: GL1C, GL2W and GL5X and Galileo: EL1X and EL5X
Phase center corrections (including corrections for phase center offset and phase center variations) are nowadays mandatory for high accuracy GNSS applications. Currently, only L1- and L2 frequencies for GPS and GLONASS are provided and published in the Antenna Exchange Format (ANTEX) maintained by the antenna working group of the International GNS...
For high accuracy GNSS applications it is necessary to take phase center corrections (PCC) into account. At the moment PCC from chamber calibrations for various signals are available, however GPS L5 as well as Galileo PCC from field calibrations are still missing. The Institut für Erdmessung (IfE) provides PCC patterns in operational mode for IGS a...
Precise GNSS applications like positioning, navigation and timing (PNT) as well as troposphere studies require consistent and accurate calibration values of receiver antennas. Nowadays, they are available by several calibration institutions based on robot or anechoic chamber concepts. The impact of phase centre model of receiver antennas on geodeti...
Senkungsvorgänge der Erdoberfläche stellen vor allem in urbanen Gebieten eine deutliche Gefährdung dar. Oftmals sind diese Senkungen durch Massenvariationen im Untergrund verursacht und führen zu langsamen, aber auch abrupten Einsenkungen der Erdoberfläche. Im Rahmen des Verbundprojektes SIMULTAN (Sinkhole Instability: MULti-scale monitoring and AN...
This dataset contains a bundle of 5 mass market receiver (ublox Neo M8T) and three geodetic graded receiver (Leica GNSS1200+GNSS, Septentrio PolaRx 5TR, Javad Delta TRE_G3T) combined in a zero baseline. The dataset captures 7 days of measurements with carrier phase, code phase, Doppler, carrier-to-noise ratio (C/N0) for GPS/GLONASS C/A code on freq...
Efficient and economic guidance of inland vessels relies on a continuous, available, reliable and precise GNSS navigation solution. Hence, below other side effects, this is especially critical when passing beneath bridges or similar infrastructures that cross waterways. They have two effects: distortion (reflection, diffraction and interruption) of...
This presentation shows the results of the application of a virtual receiver concept for inland vessel navigation. A virtual receiver is a approach, where several receiver antennas on a rigid platform are connected via a lever arm and the observations of separated, individual antenna/receiver units are combined to strengthen the satellite visibilit...
Das HITec ist für die Wissenschaft der Geodäsie und der Physik eine weltweit einzigartige Laborumgebung. Dort soll durch die Simulation verschiedenster Umweltbedingungen die Entwicklung von Multi-Sensor-Systemen (MSS) der nächsten Generation praktisch realisiert werden. Forscherteams vom Institut für Erdmessung (IfE) und dem Geodätischen Institut H...
Die Instantan mit einem stationären terrestrischen Laserscannern (TLS) aufgenommen dreidimensionale Punktwolke bezieht sich im allgemeinen auf ein lokales Horizontsystem, dessen Lage und Orientierung gegenüber einem übergeordnetem Koordinatensystem nur durch vorausberechnete Kontrollpunkte auf das notwendige geodätische Datum überführt werden kann....
This paper describes a concept to obtain a continuous navigation and position solution of inland vessels based on a multi-GNSS antenna system. Also known as, “Virtual Receiver” we utilize this approach as an alternative method with respect to a common dead reckoning procedure. Such an approach strengthens the geometry of visible GNSS satellites imm...
Dieser Vortrag gibt Einblicke in einen selbstbestimmten und verantwortungsvollen Umgang mit der eigenen Ortung via Smartphones. Genauso liefert er aber auch die Grundlagen, wie solch eine Positionierung und Navigation überhaupt möglich ist. App-Programmierung und Weiterentwicklung der eigenen Smartphones sind ebenfalls ein Thema. Wir geben Einblick...
Erdfälle sind durch Auslaugung löslicher Gesteine entstehende Senkungsereignisse an der Erdoberfläche. Insbesondere in urbanen Gebieten stellen sie eine Gefährdung dar. Im BMBF-Verbundprojekt SIMULTAN (Sinkhole Instability: integrated MULTi-scale monitoring and ANalysis) soll die Untersuchung und Überwachung von Erdfallgebieten mit Methoden der Geo...
Sinkholes occur due to leaching of soluble rocks generating subsidence at the surface. Their hazard potential is large, especially in urban areas. In the joint research project SIMULTAN (Sinkhole Instability: integrated MULTi-scale monitoring and ANalysis) the investigation and surveillance of sinkhole areas by methods of geophysics, petrophysics,...
This presentation summarises the current work on the research project SIMULTAN considering the present state of the data processing. Derived solutions from GNSS, leveling and gravimetry (absolute and relative) are shown for the location in Hamburg, Groß Flottbek.
Für urbane GNSS-Überwachungsnetze ist die Verwendung von Low-Cost GPS/GNSS-Empfängern und High-sensitive Antennen sinnvoll, um eine schnelle, individuelle und kostengünstige Anpassung an die örtlichen Gegebenheiten durchführen zu können. Bei kleinskaligen Netzgeometrien mit kurzen Basislinien eignen sich besonders leistungsstarke Einfrequenzempfäng...
This Poster summarised the current status of the work on the inter-disciplinary research project of SIMULTAN.
This poster presents the intermedeate work of an one-year student project with the topic of navigation of inland vessels. The main focus is set on the continious navigation solution during bridge crossings and the accessible position accuracy. Furthermore, this data analysis and data set is the basis to apply the concept of a virtual receiver on th...
Precise navigation and geodetic coordinate determination rely on accurate GNSS signal reception. Thus, the receiver antenna properties play a crucial role in the GNSS error budget. For carrier phase observations, a spherical radiation pattern represents an ideal receiver antenna behaviour. Deviations are known as phase centre corrections. Due to sy...
Subsidence processes in dense populated urban areas are of highly social relevance. As there is few knowledge about the evolution and the characteristic of subsidence induced land depressions or sudden sinkhole events, a detailed and interdisciplinary focus is set on this field of research especially at regions and cities with dense population. SIM...
The quality and noise of Galileo Double Differences for various signals (E1, E5a, E5b, E5a+b) in an urban Monitoring Network is studied in detail. Starting from a zero baseline on the laboratory netwoork of Institut für Erdmessung (IfE) to selected baselines of several GNSS campaigns in Bad Frankenhausen (Thuringia) and Hamburg (Groß-Flottbek) the...
Subsidence processes in dense populated urban areas are of high social relevance. As there is few knowledge about the evolution and the characteristic of subsidence induced land depressions or sudden sinkhole events, a detailed and interdisciplinary focus is set on this field of research especially at regions and cities with dense population. SIMUL...
The research project SIMULTAN applies an advanced combination of geophysical, geodetic, and modelling techniques to gain a better understanding of the evolution and characteristics of sinkholes. Sinkholes are inherently related to surface deformation and, thus, of increasing societal relevance, especially in dense populated urban areas. One work pa...
Stationary terrestrial laser scanning (TLS) provides a 3D point cloud in a local sensor-defined coordinate system. The transformation parameters of such point clouds to a global coordinate system are generally obtained by pre-surveyed control points with known geodetic datum. To improve this procedure, a direct geo-referencing method of a multi-sen...
Evaluating the impact of receiver antenna phase centre corrections (PCCs) in geodetic positioning and timing applications in a general way is quite challenging, because several estimation concepts, implementation philosophies as well as different sets of PCCs exist and interact with each other and their contributions are not identifiable. In this p...
Subsidence processes in dense populated urban areas are of societal relevance. SIMULTAN (Sinkhole instability: integrated multi-scale monitoring and analysis) aims at a novel approach to better understand the evolution and characteristics of sinkholes, which are highly correlated with surface deformation. An integrated approach to monitor sinkhole-...
Global satellite navigation systems (GNSS) are a standard measurement device for deformation monitoring. In many applications, double-differences are used to reduce distance dependent systematic effects, as well as to eliminate the receiver and satellites clock errors. However, due to the navigation principle of one way ranging used in GPS, the geo...
For precise GNSS applications like positioning, navigation and timing (PNT) as well as for troposphere studies, stable and accurate calibrations of the carrier phase center variations (PCV) for individual antennas have to be provided by calibration institutions. Beside an anechoic chamber calibration, the Institut für Erdmessung (IfE) uses a field...
Several contributions and papers in geodesy intensively discuss the impact of the variability of GPS/GNSS absolute phase centre corrections (PCCs) directly on the positioning domain, neglecting any studies on the observation domain. Furthermore, it is very complex to evaluate in a general way the impact of several PCCs in geodetic positioning due t...
Precise Point Positioning (PPP) is used in a broad variety of applications to determine very economically high
precision parameters for positioning, navigation and timing. In comparison to traditional differential approaches, PPP with undifferenced phase measurements is highly attractive, since the effort on the user side can be reduced to minimum,...
Die globale Positionierung, Navigation sowie Zeit- und Frequenzübertragung [positioning, navigation and timing] (PNT) ist in der heutigen Gesellschaft zu einem integralen Bestandteil des täglichen Lebens geworden, so dass die präzise und autonome Georeferenzierung in der letzten Dekade in weiten Teilen unseres Lebensbereiches rasant Einzug gehalten...
The Institut für Erdmessung (IfE) is an official IGS calibration institution, calibrating phase center variations (PCV) for receiver antennae routinely in the field, using the actual GNSS satellite signals in space. Current research activities focus on the antenna code phase calibration with the Hannover Concept of absolute antenna calibration. The...
Group Delay Variations (GDVs) are azimuth and elevation dependent code delays that can limit the accuracy of the GNSS code observables. This contribution focuses on the GDV determination and discusses several solutions with respect to repeatability and separability. On-site tests at a laboratory network as well as simulations of several time links...
For direct geo-referencing of static terrestrial laser scans a method developed at the Geodetic Institute of the Leibniz Universitaet Hannover utilises an eccentrically mounted GNSS antenna on top of the laser scanner. The at least 360 degree rotation about its vertical axis is suitable for deriving the position as well as the azimuthal orientation...
For time and frequency transfer as well as navigation applications, like, e.g., precise guided landing approaches, GNSS code observables are widely used. In addition to the well known error budget, code observables seem to be affected by Group Delay Variations (GDV), induced by the radiation pattern of the receiving antenna. The performance of the...
With the Hannover concept of absolute field calibration of GNSS antennae the determination of receiver antenna Phase Center Variations (PCV) can be done routinely for the GPS and GLONASS L1 and L2 frequencies, respectively. The need of multi-GNSS and multi-frequency applications - demanded by a broader navigation community - tends to a combined est...
