Leinen

Dr.-Ing. Stefan Leinen

Senior Scientist

 

Scope of Activities

Teaching

Bachelor of Science Civil Engineering and Geodesy

  • Parameter Estimation I (4. Semester, 6 CP, 3+1 hours per week)

Master of Science Geodesy and Geoinformation

  • Parameter Estimation II (1. Semester, 6 CP, 3+1 hours per week)
  • Parameter Estimation III (3. Semester, 3 CP, 1+1 hours per week)
  • Geodetic Seminar II (2. Semester, 3 CP, 0+2 hours per week)
  • Seminar Parameter Estimation (4. Semester, 3 CP, 1+1 hours per week)
 

Research

High-precision kinematic GNSS positioning

The main field of research is the use of the global navigation satellite systems (GNSS, at current mainly GPS, partly Glonass, in the future Galileo) for hich-precision applications in geodesy and navigation. The following topics are in the center of the research works:

OTF algorithms and real-time capability:

Aim of the work is the development of methods and algorithms which reliably enable a precise (it means differential mode with phase observations) kinematic (moving systems) positioning in real-time (RTK, real-time kinematic). This should work over long distances (i.e. excceding a local working area of 10 to 25 km, reaching up over more than 50 km). Main point is the development of algorithms for the ambiguity determination while in motion (OTF, on-the-fly) with the necessary robustness against systematic error effects in the GNSS observations.

GNSS/INS integration:

By integrating GNSS and INS into a hybrid system their complementary characteristics respectively advantages like the high absolute and almost time-constant accuracy of GNSS on the one hand and the good relative accuracy over short time with high positioning rate of the INS on the other do supplement each other quite well. The institute's long tradition in this field (e.g. by its participation in the 'Sonderforschungsbereich' 228 High-Precision Navigation) is continued by further enhancements of the existing system based on a Honeywell Lasernav II INS. The focus of the further works lies on investigations and studies about the suitability of so-called low-cost sensors (MEMS gyros and accelerometers and others) for the integration with respect to high-precison navigation.

Kinematic precise point positioning (PPP):

Nowadays availability of precise ephemerids for the GNSS satellites, correction models for ionospheric and tropospheric refraction and numerous other error sources affecting GNSS observations (mainly by efforts of the International GNSS Service) open an enormously increased accuracy potential for undifferenced precise point positioning (PPP). Objectives of research are the study of attainable accuracies dependent of the occupation time in case of static PPP as well as for kinematic PPP. For the latter application the development of suitable filter and parameter estimation algorithms constitutes the key issue of the works.

Innovation by Galileo:

The new GNSS Galileo will open new chances for the above mentioned and other applications and thus will be subject to scientific study and investigation. By proper simulations these chances will be analyzed in qualitative and quantitative categories. Respectively enhanced software will be available in time once the Galileo constellation reaches its full operability thus enabling the use of the increased potential for positioning.

Geodetic data analysis

Beside the traditional methods of adjustment calculations, e.g. applied to geodetic networks, the chances of alternative techniques of parameter estimation with respect to geodetic data evaluation are investigated. Hitherto carried out works and future investigations especially treat the following topics:

  • Decision making within the determination of GNSS carrier phase ambiguities by means of fuzzy-logic for optimally taking into account heterogenous information (MADM algorithm, MADM = multi attribute decision making, based on fuzzy attributes);
  • Combined parameter estimation based on GNSS, terrestrial geodetic measurements (levelling, total station, etc.), astro-geodetic observations as well as other informations with correct modeling of the relations between the geometrically and physically defined reference systems;
  • Deformation analysis based on GNSS resultats combined with terrestrial geodetic techniques, applied to natural (geodynamic) prozesses as well as the monitoring of large man-made structures;
  • Time series analysis, especially for the evaluation and interpretation of data from permanent GNSS reference stations, by means of stochastic signal analysis, signal analysis in frequency domain, wavelets, etc., aiming at a self adaption of the automated analysis process to the data quality and characteristics of the surroundings and at last the separation of systematic effects from position change components caused by deformation;

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Publications

Leinen, S. (2014): Zur Signifikanz von Phänomenen in GNSS-Zeitreihen – Der Weg zur statistisch plausiblen Aussage. in: 129. DVW-Seminar, Zeitabhängige Messgrößen – Ihre Daten haben (Mehr-)Wert, Seiten 129-147. Hannover, 26./27.02.2014.

Leinen, S., Becker, M., and Läufer, G. (2012): Effect of stochastic model fitting on the significance of CORS coordinate time series parameters. J. Appl. Geodesy, Vol. 7 (2012), pp. 1-17. DOI 10.1515/jag-2012-0038.

Leinen, S., Becker, M., Läufer, G., and Lehné, R. (2012): Blending of Reprocessed GNSS Coordinate Time Series Parameters with Geological Data. Proceedings of 16th General Assembly of WEGENER, Strasbourg, France, 17.-20.09.2012.

Dziubek, N., Winner, H., Becker, M., and Leinen, S. (2012): Sensordatenfusion zur hochgenauen Ortung von Kraftfahrzeugen mit integrierter Genauigkeits- und Integritätsbewertung der Sensorsignale. Proceedings of '5. Tagung Fahrerassistenz', Technische Universität München, 15.-16.05.2012, München.

Dziubek, N., Winner, H., Becker, M., and Leinen, S. (2011): Fahrstreifengenaue Ortung von Kraftfahrzeugen durch Datenfusion und Fehlerkompensation von Standard-Seriensensoren. Proceedings of Symposium POSNAV ITS 2011: Positionierung und Navigation für Intelligente Verkehrssysteme. Deutsche Gesellschaft für Ortung und Navigation, 22.-23.11.2011, Darmstadt.

Läufer, G., Becker, M., Leinen, S. und Heckmann, B. (2011): Untersuchung zu Stabilität, Zuverlässigkeit und Integrität des hessischen SAPOS-Referenznetzes, 2011. Proceedings of Symposium POSNAV ITS 2011: Positionierung und Navigation für Intelligente Verkehrssysteme. Deutsche Gesellschaft für Ortung und Navigation, 22.-23.11.2011, Darmstadt.

Läufer, G., Leinen, S. und Becker M. (2011): Reprozessierung der Daten des hessischen SAPOS®-Netzes und Analyse von Stationsstabilität und Geschwindigkeitsfeld. Studie für das Hessische Landesamt für Bodenmanagement und Geoinformation (HLBG), Technischer Report, 143 Seiten, Nr. IPGD-2010-03, Schriftenreihe des Instituts für Physikalische Geodäsie der TU Darmstadt, 2011.

Fernandes, R. M. S., Leinen S., Romero, I., Farah, H., Combrinck, L., and Khalil, H. (2009): AFREF08 and AFREF09: Case-studies towards the implementation of AFREF. Presentation by R. Fernandes at IAG 2009, Buenos Aires, Argentina, 31 August 2009.

Fernandes, R. M. S., Farah, H., Combrinck, L., Khalil, H., and Leinen S. (2009): Towards the implementation of AFREF: results of case-studies for the computation of the reference solution. Presentation by R. Fernandes at EGU 2009 General Assembly, Vienna, 24 April 2009.

G. Läufer, M. Becker, R. Drescher, C. Gerstenecker, S. Leinen, and S. Rödelsperger (2008): Ground based Deformation Monitoring within the Geotechnologien Project ”Éxupéry”. In Proceedings of 14th General Assembly of WEGENER, Darmstadt, Germany, 15.-18.09.2008, 2008.

Müller, K., Becker, M., and Leinen S. (2009): Realistic prediction of accuracy in urban environments with a GNSS simulation tool. Allgemeine Vermessungs-Nachrichten (AVN), ISSN 0002-5968, 8-9/2009, pages 300-307.

Becker, M., Leinen, S. und Müller, K. (2008): Analyse der Einsatzmöglichkeiten mehrerer GNSS bei stark eingeschränkter Satellitensichtbarkeit. Studie für das Hessische Landesamt für Bodenmanagement und Geoinformation (HLBG), Technischer Report, 97 Seiten, 2008.

Leinen, S., Schönemann, E., und Becker, M. (2007): Analyse, Konzeption und Dokumentation begleitend zur Einführung von Glonass und Galileo im hessischen SAPOS. Studie für das Hessische Landesamt für Bodenmanagement und Geoinformation (HLBG), Technischer Report, 83 Seiten, 2007.

Drescher, R., Leinen, S., Becker, M. (2007): Volcano monitoring by a GPS based hybrid sensor system. in Heft 28, Schriftenreihe der Fachrichtung Geodäsie, Fachbereich Bauingenieurwesen und Geodäsie, Technische Universität Darmstadt, ISBN 978-3-935631-17-4, Dezember 2007, S. 23-36.

Leinen, S., Becker, M., Lewi, E., Söhne, W., Weber, G. (2007): The New IGS Station ADIS and its Role for Geodesy and Geodynamics. submitted to Proceedings of the Symposium on occasion of the 50th anniversary of the Addis Ababa University Geophysical Observatory.

Leinen, S., Becker, M., Dow., J., Feltens, J., and Sauermann, K. (2007): Geodetic Determination of Radio Telescope Antenna Reference Point and Rotation Axis Parameters. Journal of Surveying Engineering, Vol. 133, no. 2, May 1, 2007, pp. 41-51. ISSN 0733-9453/2007/2-41-51.

Becker, M., und Leinen, S. (2006): Navigation mit Galileo – Neue Perspektiven für Verkehrsanwendungen. thema Forschung 2/2006, TU Darmstadt, S. 84-87.

LEINEN, S., and BECKER, M. (2005): Determination of precise ITRF positions for ground-station satellite tracking antennae. Proceedings of ION GNSS 2005, September 13-16, 2005, Long Beach, California, USA.

FELTENS, J., DOW, J., BECKER, M., LEINEN, S., SAUERMANN, K. (2005): The ESA Tracking Site Directory II. in Proceedings of the 28th Antenna Workshop on Space Antenna Systems and Technologies, ESA/ESTEC, Noordwijk, The Netherlands, May 31 to June 3, 2005.

LEINEN, S. (2004): ESA Tracking Site Directory – works for update from version 1 to 2 in the years 2002-2004. Issue 1.4, December 9, 2004, Report of IPGD to European Space Operations Centre (ESOC).

LEINEN, S. (2001): Fuzzy-Logic based GPS On-The-Fly Ambiguity Search. Proceedings of First International Symposium on Robust Statistics and Fuzzy Techniques in Geodesy and GIS, March 12-16, 2001, Zürich, Switzerland.

LEINEN, S., GROTEN, E.; AYAN,T., ALANKO, G., CELIK, R., DENLI, H., ÖZLÜDEMIR, T., and EROL, S. (1999): Deformation Monitoring of Karasu Viaduct with GPS and Levelling. Proceedings of Third Turkish-German Joint Geodetic Days, Istanbul, Turkey.

CELIK, R.N., T. AYAN, H. DENLI, T. ÖZLÜDEMIR, S. EROL, E. GROTEN and S. LEINEN (1999): Land Sliding Monitoring Using GPS and Conventional Techniques in Gürpinar. Proceedings of Third Turkish-German Joint Geodetic Days, Istanbul, Turkey.

RABAH M., and LEINEN S. (1998): Real-Time Crustal Movement Determination over Long Baselines. Proceedings of Ninth International Symposium on Recent Crustal Movements, November 1998, Cairo, Egypt.

LEINEN S., GROTEN E. and AYAN T. (1998): The Combined Use of GPS and Levelling for Deformation Monitoring – Experiences from a Large Highway Viaduct. Proceedings of Ninth International Symposium on Recent Crustal Movements, November 1998, Cairo, Egypt.

GROTEN E., LEINEN S. and AYAN T. (1998): Deformation Monitoring around a Large Viaduct close to Istanbul using GPS and Levelling. Proceedings of Symposium Geodynamics of the Alps-Adria Area, 28.9.-2.10.98, Dubrovnik, Croatia.

HEINZE O., LEINEN S., MATHES A., SÖHNE W. (1997): Erprobung und Anwendung Geodätischer Trägheitsnavigationssysteme, in Abschlußbericht des SFB 228, September 1997, Stuttgart.

AYAN T., CELIK R., ALANKO G., DENLI H., ÖZLÜDEMIR T., GROTEN E., LEINEN S., TRAISER J. (1997): Die ersten Ergebnisse der Deformationsmessungen mit GPS auf dem Karasu-Viadukt, Proceedings of Second Turkish-German Joint Geodetic Days, May 1997, Berlin.

LEINEN S. (1997): Hochpräzise Positionierung über große Entfernungen und in Echtzeit mit dem Global Positioning System. DGK, Reihe C, Heft Nr. 472.

RABAH M., GROTEN E. and LEINEN S. (1996): Developing a Real-Time Algorithm for Detecting and Estimating Cycle-Slips in Undifferenced Mode. Proceedings of IAG Regional Symposium on Deformations and Crustal Movement Investigations Using Geodetic Techniques, Aug. 31 – Sept. 5, 1996, Szekesfehervar, Hungary.

GROTEN E., LEINEN S. and MATHES A. (1995): About the Possibility of Monitoring Deformations by a Real-Time DGPS Network. Proceedings of First Turkish-German Joint Geodetic Days, 25-27 September 1995 , Istanbul.

LEINEN S., MATHES A. und GIANNIOU M. (1995): Zentimetergenauigkeit in Echtzeit – Von der Offline-Auswertung zum automatisierten GPS-Meßsystem. DVW-Hessen Mitteilungen 1/1995.

GROTEN E., LEINEN S., KARTAL F., HOSBAS G., ERSOY N., ERKÜCÜK G., GÜZEL G., UZEL T. and EREN K. (1994): Dam Monitoring By Continous GPS Observations. Proceedings of First Turkish International Symposium on Deformations, 5-9 September 1994 , Istanbul.

LEINEN S., WACHTER J. und GOECKE W. (1994): Nutzung von GPS zur Erarbeitung von Planungsgrundlagen für ein Straßenbauprojekt in Benin/Westafrika. Allgemeine Vermessungs-Nachrichten, 11-12, 1994, S. 439-446.

BECKER M., GROTEN E., LEINEN S. und SAUERMANN K. (1993): Studie zu Einrichtung und Betrieb von DGPS-Referenzstationen in Hessen. Report des IPGD für das Hessische LVA.

JÄGER R. and LEINEN S. (1992): Spectral Analysis of GPS-Networks and -Processing Strategies due to Random and Systematic Errors. Proceedings of 6th International Geodetic Symposium on Satellite Positioning, Columbus, Ohio (USA).

LEINEN S., JÄGER R., ILLNER M. and MIERLO J. van (1991): GPS-Alps-Traverse: Determination of an optimum session-/fiducialpoint-design and processing strategy by simulation studies and theoretical investigations reagarding sources of random and systematic errors with respect to precision, bias and sensitivity. Paper presented at the IUGG General Assembly, Wien 1991, published in: Report of SFB 108, University of Karlsruhe, Germany, 1992.

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