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For Section 1.2 “Global Geomonitoring and Gravity Field” outer branch in Oberpfaffenhofen (near Munich) we invite applications – under restriction of final funding - for a

Postdoc Position: Nerograv Istore project

Job Vacancy No. 1846

GFZ’s Section 1.2 routinely estimates various Earth system parameters which describe the Earth's geometrical and physical shape (e.g. ground station coordinates or gravity field spherical harmonic coefficients) and its orientation in space (Earth orientation parameters (EOP)) based on observations of satellite orbit dynamics which can be observed by various types of satellite tracking data such as Satellite Laser Ranging (SLR), Global Navigation Satellite System (GNSS), Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) and other data. The current main focus of our research is the GRACE Follow-On mission, which we have successfully implemented with NASA. Additionally, we analyze other Low Earth Orbiters such as TerraSAR-X, TanDEM-X, JASON, SENTINELs etc., higher altitude missions as the GNSS constellations, or geodetic SLR satellites such as LAGEOS or LARES.
The satellite orbit dynamics are driven by conservative (the gravity field) and non-conservative (the drag by the atmosphere, pressure by solar radiation, etc.) forces which are modeled and parameterized in our core Earth Parameter and Orbit System software package EPOS (about 130.000 lines of code and comments). By evaluating the observations in the least squares sense, the parameters we are interested in can be inferred with high accuracy and at the same time highly accurate orbits can be determined. Keeping EPOS conform to the most recent international standards allows us to support the international IAG services ILRS (International Laser Ranging Service) and IDS (International Doris Service) by operating an Analysis Center and an Associate Analysis Center, respectively.
The Research Group NEROGRAV (New Refined Observations of Climate Change from Spaceborne Gravity Missions), expected to be funded by the German Research Foundation (DFG, final decision early December 2018), is aiming at improving and better understanding of sensor data, background models, and processing strategies of satellite gravimetry in order to increase resolution, accuracy, and long-term consistency of mass transport series from satellite gravimetry. Within NEROGRAV we will run the individual project “Improved STOchastic modelling in GRACE/GRACE-FO REal data processing (ISTORE)” where we want to take into account extensive stochastic error characteristics of the main GRACE and GRACE-FO observation types inter-satellite ranging (microwave, laser) and accelerometer readings and of the main non-tidal and tidal background models. This requires a proper implementation and validation of linear error propagation into the EPOS software and the development of a software environment for Monte Carlo simulations. Challenges will lie in the usage of huge variance-covariance matrices.

Your responsibilities:

  • handling of the orbit and Earth parameter determination software EPOS and its periphery for GRACE/GRACE-FO data analysis
  • implementation of extensive stochastic modelling in EPOS under FORTRAN90
  • implementation of a Monte Carlo simulation environment under LINUX
  • validation of the implementations
  • collaboration in the research group NEROGRAV
  • preparation and presentation of results in project meetings, symposia, and in scientific journals

Your qualifications:

  • Master's degree and PhD in Geodesy or equivalent
  • expertise in satellite geodesy
  • extended experience in Precise Orbit Determination
  • extended experience in estimation of gravity field parameters and other geodetic parameters from satellite tracking data
  • extended experience in evaluating the space-geodetic observations high-low GNSS, low-low inter-satellite links, SLR, and others
  • expertise in least squares adjustment (observation level) and linear algebra (normal equation level)
  • expertise in data processing under LINUX and shell scripting
  • expertise in FORTRAN
  • ability for independent working
  • ability for and willingness to work in a multidisciplinary team and to communicate with external partners
  • good command of English
Starting date: 1st April 2019
Fixed term: 3 years with the option of extension
Salary: The pay scale grouping will be according to pay group 13 TVöD-Bund (Tarifgebiet West) provided that all tariff related and personal requirements are met.
Working hours: full-time (currently 39 h/week)
Location: Oberpfaffenhofen
You can expect a very diverse and challenging job in an international work environment that is characterized by exciting research projects. The compatibility of work and family life is of particular concern to the GFZ. Therefore, it offers the opportunity for flexible working time and workplaces. Moreover, there is a kindergarten located on the research campus.
The GFZ is a partner with Geo.X (www.geo-x.net), and as such it is well connected with other geoscience institutions in Potsdam und Berlin. Geo.X forms the largest regional cluster of geoscientific expertise in Europe and offers excellent opportunities for cooperation and development.
Please submit your application by 12th December 2018.
Equal opportunity is an inherent part of our personnel policy. Therefore we are particularly welcoming applications from qualified women. Severely disabled persons will be given preferential treatment in the case of equal qualification.
We will retain your application documents for at least three months, even if the application is not successful.
If you have any questions regarding this job offer, please feel free to call Ms Buge at +49 (0) 331-288-28878.