Details
Originalsprache | Englisch |
---|---|
Titel des Sammelwerks | Observing our Changing Earth - Proceedings of the 2007 IAG General Assembly |
Seiten | 293-299 |
Seitenumfang | 7 |
Publikationsstatus | Veröffentlicht - 2009 |
Veranstaltung | 24th General Assembly of the International Union of Geodesy and Geophysics, IUGG 2007 - Perugia, Italien Dauer: 2 Juli 2007 → 13 Juli 2007 |
Publikationsreihe
Name | International Association of Geodesy Symposia |
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Band | 133 |
ISSN (Print) | 0939-9585 |
Abstract
The research aims at an investigation of the optimal choice of local base functions, to derive a regional solution of the gravity field. Therefore, the representation of the gravity field is separated into a global and a residual signal, which includes the regional details. To detect these details, a superposition of localizing radial base functions is used. The base functions are developed from one mother function, and modified by four parameters. These arguments can be separated into two coordinates, one scale factor and a shape parameter. The observations of a few residual gravity fields are simulated by orbit integration and the energy-balance technique, in order to test the current approach. After selecting a region of interest, the parameters of the base functions are estimated. In order to get the optimal positions, two searching algorithms are compared. In the first algorithm the scale factors are estimated, while the positions and shape parameters are fixed. This method requires no initial values, because of the linear, but ill-posed and maybe ill-conditioned problem, but usually a regularization is necessary. The second algorithm searches possible positions for one base function in each step, until a termination condition is fulfilled, and improves the positions and scale factors in one adjustment. The results in the second case are better and faster for the test fields, but they depend on the initial values, the number of iterations and an assumption of an approximate constant orbit height.
ASJC Scopus Sachgebiete
- Erdkunde und Planetologie (insg.)
- Computer in den Geowissenschaften
- Erdkunde und Planetologie (insg.)
- Geophysik
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Observing our Changing Earth - Proceedings of the 2007 IAG General Assembly. 2009. S. 293-299 (International Association of Geodesy Symposia; Band 133).
Publikation: Beitrag in Buch/Bericht/Sammelwerk/Konferenzband › Aufsatz in Konferenzband › Forschung › Peer-Review
}
TY - GEN
T1 - Representation of Regional Gravity Fields by Radial Base Functions
AU - Antoni, M.
AU - Keller, W.
AU - Weigelt, M.
PY - 2009
Y1 - 2009
N2 - The research aims at an investigation of the optimal choice of local base functions, to derive a regional solution of the gravity field. Therefore, the representation of the gravity field is separated into a global and a residual signal, which includes the regional details. To detect these details, a superposition of localizing radial base functions is used. The base functions are developed from one mother function, and modified by four parameters. These arguments can be separated into two coordinates, one scale factor and a shape parameter. The observations of a few residual gravity fields are simulated by orbit integration and the energy-balance technique, in order to test the current approach. After selecting a region of interest, the parameters of the base functions are estimated. In order to get the optimal positions, two searching algorithms are compared. In the first algorithm the scale factors are estimated, while the positions and shape parameters are fixed. This method requires no initial values, because of the linear, but ill-posed and maybe ill-conditioned problem, but usually a regularization is necessary. The second algorithm searches possible positions for one base function in each step, until a termination condition is fulfilled, and improves the positions and scale factors in one adjustment. The results in the second case are better and faster for the test fields, but they depend on the initial values, the number of iterations and an assumption of an approximate constant orbit height.
AB - The research aims at an investigation of the optimal choice of local base functions, to derive a regional solution of the gravity field. Therefore, the representation of the gravity field is separated into a global and a residual signal, which includes the regional details. To detect these details, a superposition of localizing radial base functions is used. The base functions are developed from one mother function, and modified by four parameters. These arguments can be separated into two coordinates, one scale factor and a shape parameter. The observations of a few residual gravity fields are simulated by orbit integration and the energy-balance technique, in order to test the current approach. After selecting a region of interest, the parameters of the base functions are estimated. In order to get the optimal positions, two searching algorithms are compared. In the first algorithm the scale factors are estimated, while the positions and shape parameters are fixed. This method requires no initial values, because of the linear, but ill-posed and maybe ill-conditioned problem, but usually a regularization is necessary. The second algorithm searches possible positions for one base function in each step, until a termination condition is fulfilled, and improves the positions and scale factors in one adjustment. The results in the second case are better and faster for the test fields, but they depend on the initial values, the number of iterations and an assumption of an approximate constant orbit height.
KW - Energy-balance technique
KW - Local base function
KW - Radial base function
KW - Regional gravity field
KW - Searching algorithms
UR - http://www.scopus.com/inward/record.url?scp=84875423180&partnerID=8YFLogxK
U2 - 10.1007/978-3-540-85426-5_34
DO - 10.1007/978-3-540-85426-5_34
M3 - Conference contribution
AN - SCOPUS:84875423180
SN - 9783540854258
T3 - International Association of Geodesy Symposia
SP - 293
EP - 299
BT - Observing our Changing Earth - Proceedings of the 2007 IAG General Assembly
T2 - 24th General Assembly of the International Union of Geodesy and Geophysics, IUGG 2007
Y2 - 2 July 2007 through 13 July 2007
ER -