Gy. Tóth | 2019-12-05

December 2019

General Announcements

  • International Symposium in honour of Professor Erik W. Grafarend

Meetings Calendar

IAG Sponsored Meetings

  • 11th IVS General Meeting
  • 19th International Symposium on Geodynamics and Earth Tides (G-ET Symposium 2020)
  • IGS Workshop "IGS 2020: Science from Earth to Space"
  • 43rd COSPAR Scientific Assembly
  • 2nd International Symposium of Commission 4: Positioning and Applications
  • 22nd meeting of the Consultative Committee for Time and Frequency (CCTF)
  • IAG Scientific Assembly

IAG Related Meetings

  • 3rd UN GGIM Subcommittee on Geodesy Plenary Meeting
  • 6th High Level Forum on UN GGIM
  • EGU General Assembly 2020
  • FIG Working Week 2020
  • AOGS2020 17th Annual Meeting


  • ILRS Technical Workshop 2019

General Announcements

International Symposium in honour of Professor Erik W. Grafarend

Photo: Tilo Reubelt

International Symposium in honour of Professor Erik W. Grafarend was organized at the University of Stuttgart in the evening of November 11, 2019. More than 25 colleagues gathered on this intimate occasion to congratulate and celebrate the 80th anniversary of Erik Grafarend. Topics in the presentations covered many different activities of Erik Grafarend, including his long-time relations to Hungary, Sweden and Finland, IAG, Alexander von Humboldt foundation, and more general topics related on his research and publications. The excellent “Jazz Combo Stufe 7” orchestra entertained the audience during the intermission.

Congratulations to Erik Grafarend also on behalf of IAG!

Markku Poutanen

IAG Secretary General

Commemorative speech by Fernando Sansò

Erik Grafarend is now 80 years old; a life dedicated to science, teaching and research rooted in Geodesy, but with branches in many different fields. After the heroic era of Geodesy in the second half of the last century, dominated by scientists like Baarda, Bjerhammar, Moritz, Kaula, Krarup, Marussi and others, the figure of Grafarend stands out as an epigone of the past and a pillar of the future with the support of the powerful arm of Alexander von Humboldt foundation, he has educated and spread around the world dozens of important researchers, till very recent days. With them, his school, he has investigated in depth practically all areas of our science, bringing in it his personal views, often originated in physical and mathematical background. It is impossible of course to analyze his results in a few pages, yet it is instructive to list the many compartments where his thought has impressed a visible track.

Relativistic Geodesy: exploring the applications of Special and General Relativity approach to geodetic problems as the definition of a relativistic Reference-System, the relativistic description of Earth rotation,  relativistic effects in satellite orbits determination etc.

Statistical Geodesy: optimal estimation/prediction theory with particular care of the rank deficiency problem, linear and non-linear models. Total Least Squares, variance-covariance estimation, prediction with random effects models, optimal regularization etc.

Geodetic Networks: networks in 3D and 4D, definition of the geodetic datum, free networks, second and third order design optimization, deformation analysis, strain matrices and their statistical analysis etc.

Geophysical Geodesy: dynamics of the rotating planet, continuum dynamics and deformation, Love-Shida numbers, tidal theories etc.

Satellite Geodesy and Navigation: orbit determination, 3D and 4D networks including satellites and their dynamics, rank deficiency in networks with spatial observations (Doppler, GPS) , observables of INS-GPS systems, gravity from space (the invariants approach) etc.

Geometric Geodesy and Mapping: differential forms in Geodesy, coordinate transformations, Cartan frames and calculus, the holonomity  problem with geodetic coordinates, rays geometry in a refractive medium, map projections and their transformations, optimal map projections, etc.

The Geodetic Boundary Value Problem: various formulations of the GBVP (Stokes, Molodensky, overdetermined, time -varying, a GBVP between two boundaries, etc.)

Geoid and Height Datum: geoid and telluroid definition, the Stokes problem for the Ellipsoid, analysis with ellipsoidal harmonics, W0 estimation, etc.

Indeed geodesy at 360°! And note that just a few months ago I had the pleasure to read a long report on Anholonomity in Pre and Relativistic Geodesy! Two trademarks of Erik’s work, joined in one paper.

So, not only we have to acknowledge the gigantic work done by Erik Grafarend but we have to recognize too that he continues to contribute to our science, so we are looking forwards for his new achievements in the future.

Fernando Sansò 

Meetings Calendar

IAG Sponsored Meetings

IAG Related Meetings

Further details are available in the IAG Event Calendar at:


ILRS Technical Workshop 2019,

Stuttgart, Germany, October 20-25, 2019 

This year’s International Laser Ranging Service (ILRS) Technical Workshop was hosted by German Aerospace Center (DLR) in Stuttgart, Germany, from October 21st  to 25th. Following the motto “Laser ranging: To improve economy, performance, and adoption for new applications” the presentations were focused on the technical challenges for the satellite laser ranging (SLR) ground segment. 

During the introductory session, invited speakers presented their view of the current state of the ILRS station network and its possible evolution in the next years. Subsequent sessions focused on the improvement of current systems, synergies with other technologies (such as laser communications or time transfer) and new technical approaches for future ranging systems. The final session was focused on safety and security, especially laser safety in respect to aircrafts passing over the stations.

Participants of the workshop

To encourage discussion and exchange among the participants, some sessions included dedicated time slots for plenary or panel discussions. These were very well received and saw a lot of contributions from many different participants. To highlight the importance of poster presentations, a separate time slot has been reserved for poster viewing, and the three best posters have been awarded a prize. The week was rounded off by a bus tour to the two SLR stations in Stuttgart and a conference dinner. 

The workshop was preceded by a one-day SLR school on October 20th, which provided a range of entry level talks for students and people new to SLR. This first edition of such a school for SLR related topics was met with overwhelming interest and was seen as a good way to pass on first-hand knowledge to a younger generation. The lectures have been videotaped and is available on the workshop website.

(Photo: Toshimichi Otsubo / Hitotsubashi University)

With its 150 participants from more than twenty countries and more than seventy presentations (oral and poster), the workshop mirrored the importance of the global laser ranging network and its many active developments. More information, including abstracts and presentations, can be found on the workshop website: 

Daniel Hampf

Chair of local organising committee

German Aerospace Center (DLR), Institute of Technical Physics, Stuttgart, Germany

IAG Events