Details
| Original language | English |
|---|---|
| Title of host publication | Gravity, Geoid and Earth Observation - IAG Commission 2 |
| Subtitle of host publication | Gravity Field |
| Pages | 497-504 |
| Number of pages | 8 |
| Publication status | Published - 2010 |
| Event | IAG International Symposium on "Gravity, Geoid and Earth Observation 2008" - Chania, Crete, Germany Duration: 23 Jun 2008 → 27 Jun 2008 |
Publication series
| Name | International Association of Geodesy Symposia |
|---|---|
| Volume | 135 |
| ISSN (Print) | 0939-9585 |
Abstract
New gravity field models incorporate GRACE data for the long wavelengths since it is one of the best available data sources. However, considering e.g. the degree difference RMS between EGM2008 and GGM02s, also discrepancies between these models occur which cannot solely be explained by numerical inaccuracies. Their validation is difficult since comparisons with existing GRACE models will always be biased. Maybe the best independent data set on a global scale is the CHAMP data. One the other hand, it is known that the accuracy of these solutions is approximately one order of magnitude worse than GRACE-only solutions. In this research, it has been investigated if CHAMP can serve as an indicator in the comparison of EGM2008 and GGM02s. The primary data source of CHAMP is its position and velocity measurements derived from GPS. They are based on purely kinematic orbits, which are independent of any a priori information and are provided by the Institute for Astronomical and Physical Geodesy at the Technical University Munich for the period of April 2002 to February 2004. The comparison is based on a global solution and a local refinement with Slepian functions in order to further improve the quality of the CHAMP solution. The latter is adopted because it can make better use of information in high-latitude areas where the data density is higher. However, the solutions are solely based on GPS measurements which have a poorer quality compared to the K-band ranging system of GRACE and thus prevents a real statement about the quality of the EGM2008.
Keywords
- CHAMP, Energy balance approach, GRACE, Slepian functions, Spherical harmonics
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Computers in Earth Sciences
- Earth and Planetary Sciences(all)
- Geophysics
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Gravity, Geoid and Earth Observation - IAG Commission 2: Gravity Field. 2010. p. 497-504 (International Association of Geodesy Symposia; Vol. 135).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Evaluation of EGM2008 by Comparison with Global and Local Gravity Solutions from CHAMP
AU - Weigelt, M.
AU - Sneeuw, N.
AU - Keller, W.
PY - 2010
Y1 - 2010
N2 - New gravity field models incorporate GRACE data for the long wavelengths since it is one of the best available data sources. However, considering e.g. the degree difference RMS between EGM2008 and GGM02s, also discrepancies between these models occur which cannot solely be explained by numerical inaccuracies. Their validation is difficult since comparisons with existing GRACE models will always be biased. Maybe the best independent data set on a global scale is the CHAMP data. One the other hand, it is known that the accuracy of these solutions is approximately one order of magnitude worse than GRACE-only solutions. In this research, it has been investigated if CHAMP can serve as an indicator in the comparison of EGM2008 and GGM02s. The primary data source of CHAMP is its position and velocity measurements derived from GPS. They are based on purely kinematic orbits, which are independent of any a priori information and are provided by the Institute for Astronomical and Physical Geodesy at the Technical University Munich for the period of April 2002 to February 2004. The comparison is based on a global solution and a local refinement with Slepian functions in order to further improve the quality of the CHAMP solution. The latter is adopted because it can make better use of information in high-latitude areas where the data density is higher. However, the solutions are solely based on GPS measurements which have a poorer quality compared to the K-band ranging system of GRACE and thus prevents a real statement about the quality of the EGM2008.
AB - New gravity field models incorporate GRACE data for the long wavelengths since it is one of the best available data sources. However, considering e.g. the degree difference RMS between EGM2008 and GGM02s, also discrepancies between these models occur which cannot solely be explained by numerical inaccuracies. Their validation is difficult since comparisons with existing GRACE models will always be biased. Maybe the best independent data set on a global scale is the CHAMP data. One the other hand, it is known that the accuracy of these solutions is approximately one order of magnitude worse than GRACE-only solutions. In this research, it has been investigated if CHAMP can serve as an indicator in the comparison of EGM2008 and GGM02s. The primary data source of CHAMP is its position and velocity measurements derived from GPS. They are based on purely kinematic orbits, which are independent of any a priori information and are provided by the Institute for Astronomical and Physical Geodesy at the Technical University Munich for the period of April 2002 to February 2004. The comparison is based on a global solution and a local refinement with Slepian functions in order to further improve the quality of the CHAMP solution. The latter is adopted because it can make better use of information in high-latitude areas where the data density is higher. However, the solutions are solely based on GPS measurements which have a poorer quality compared to the K-band ranging system of GRACE and thus prevents a real statement about the quality of the EGM2008.
KW - CHAMP
KW - Energy balance approach
KW - GRACE
KW - Slepian functions
KW - Spherical harmonics
UR - http://www.scopus.com/inward/record.url?scp=84884381110&partnerID=8YFLogxK
U2 - 10.1007/978-3-642-10634-7_66
DO - 10.1007/978-3-642-10634-7_66
M3 - Conference contribution
AN - SCOPUS:84884381110
SN - 9783642106330
T3 - International Association of Geodesy Symposia
SP - 497
EP - 504
BT - Gravity, Geoid and Earth Observation - IAG Commission 2
T2 - IAG International Symposium on "Gravity, Geoid and Earth Observation 2008"
Y2 - 23 June 2008 through 27 June 2008
ER -