FIG Congress Istanbul 2018

FIG Congress was held in Istanbul 6 to 11 May 2018.

FIG Congress 2018

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Champ's GGM Development at AIUB

The work on Champ's GGM at  the Astronomical Institute, University of Berne (AIUB) is led by Lars Prange (Prange et al, 2009). The team consist also Jaggi, Beutler, Dach and Roland L Mervart. Early work was implemented using Champ data set March 2002 to January 2003 (342 days). The computation is using celestial mechanic approach and make use of Eigen2 as priori gravity model

The result ~ AIUB-Champ01S is complete to degree and order 90. The accuracy is determined with comparison made against Eigen-GL04C, EGM96 and ITG Champ01 (considered the best Champ only model). AIUB then is claimed as giving the best result – proven at higher degree coefficient solution; but slightly minor problem in lower degree harmonic degree 15 to 20.

Adrian Jaggi - Bern Universitat (researchgate)

Roland Mervart (researchgate)

now at TU Prague
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Champ GGM by TU Munich

Other than GFZ, the development of GGM in the early period of Champ mission was also accomplished by geodesists at the Technical University of Munich (TUM). Two versions of Champ GGM was contributed by TUM i.e., TUM-1S (in 2003) and TUM-2Sp (in 2005).

• TUM-1S utilized half year of Champ data (Gerlach et al, 2003)
• The methodology used is the energy integral technique as opposed to the analysis of orbit perturbation (which was used in the classical approach of gravity field determination)
• While TUM-2Sp used one year of Champ data (Foldvary et al, 2005)
• Methodology employed is the energy balance approach and kinematics Champ orbit

Christian Gerlach is now with Bavarian Academy of Sciences and Humanities, Commission of Geodesy and Glaciology (BAdW) Munchen. He is also with Norwegian U of Life Sciences (supervising MSc Vegard Ophaug in 2013).

Christian Gerlach (link)

now Assoc Prof at Norwegian U of Life Sciences 

Lorant Foldvary is now at Geodesy Dept, TU Budapest (BUTE).

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Eigen GGMs and Contribution by Reigber

If we look at the list of GGMs deposited at ICGEM we will noticed the GGM came in various names and one such name is Eigen. Eigen stands for European Improved Gravity model of the Earth by New techniques. Eigen is the GGMs produced as results of a long ‐time close cooperation in the field of global gravity field determination between GFZ Potsdam and GRGS/CNES Toulouse, France.

The development of Eigen began way back in 2002 with the first two sets i.e., Eigen-1 and Eigen-1S. These earlier works on Eigen at GFZ were carried out by Christoph Reigber (at GFZ) and Georges Balmino (at GRGS).

The development of Eigen-1 was highlighted in “Global gravity field recovery using solely GPS tracking and accelerometer data from Champ” available in textbook Earth Gravity Field From Space – from sensors to Earth Sciences, Space Sciences Series of ISSI, Vol 17, Springer 2003.

Eigen-1S is described in “A high quality global gravity field model from Champ Gps tracking data and accelerometry” published in Geophys Res Letter 29, 2002 (available in folder G07). The solution uses three month of Champ data (88 days) from July to Dec 2000.

Eigen-2 can be read in “The Champ-only Earth gravity filed model Eigen-2” appeared in Adv Space Res 31, 2003 (also available in folder G07). Eigen-2 utilized six months data of Champ mission. The data came from two stages i.e., July to Dec 2000 and Sept-Dec 2001.

Eigen-Champ03S “Earth gravity field and seasonal variability from Champ” published in book Earth Observation with Champ – Results from three years in orbit, Springer, 2004.

The later works on Eigen at GFZ (after Reigber) continued with the leading role taken over by another geodesist - Christoph Forste.

Prof Emeritus Christoph Reigber

(PhD 1969, Dipl-Ing 1965 & Habil 1974 TUM)

"Zur Bestimmung des Gravitationsfeldes der Erde aus Satellitenbeobachtungen" - 1969

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Gravity Field Measurement from Spaceborne Satellites

Perlu baca semula kandungan lecture ini.

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