Details
Translated title of the contribution | Regional gravity field modeling by means of Slepian and radial base functions |
---|---|
Original language | German |
Pages (from-to) | 120-129 |
Number of pages | 10 |
Journal | ZFV - Zeitschrift fur Geodasie, Geoinformation und Landmanagement |
Volume | 133 |
Issue number | 2 |
Publication status | Published - 2008 |
Externally published | Yes |
Abstract
The satellite missions CHAMP and GRACE have been launched in 2000 and 2002 respectively, to determine the static and the time variable gravity field of the Earth. Usually, the gravity field, which is derived from the observations of the missions, is modeled by a sum of spherical harmonics. It turns out, however, that these global base functions are not able to represent all the local details of the data. This study demonstrates two methods of modeling the residual signal by localizing base functions. On the one hand, the radial base functions are used, on the other hand the Slepian functions, which are generated by orthogonalization of spherical harmonics on a subspace of the sphere. If fall parameters of the radial base functions are estimated, the non-linear problem demands initial values. Additionally a line search is necessary to improve the convergence of the solution and a penalty method to fix the estimated parameters in a reasonable interval. The achieved accuracy and the numerical efforts are compared in a simulation for both systems of localizing functions.
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In: ZFV - Zeitschrift fur Geodasie, Geoinformation und Landmanagement, Vol. 133, No. 2, 2008, p. 120-129.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Regionale Schwerefeldmodellierung durch Slepian- und Radiale Basisfunktionen
AU - Antoni, Markus
AU - Keller, Wolfgang
AU - Weigelt, Matthias
PY - 2008
Y1 - 2008
N2 - The satellite missions CHAMP and GRACE have been launched in 2000 and 2002 respectively, to determine the static and the time variable gravity field of the Earth. Usually, the gravity field, which is derived from the observations of the missions, is modeled by a sum of spherical harmonics. It turns out, however, that these global base functions are not able to represent all the local details of the data. This study demonstrates two methods of modeling the residual signal by localizing base functions. On the one hand, the radial base functions are used, on the other hand the Slepian functions, which are generated by orthogonalization of spherical harmonics on a subspace of the sphere. If fall parameters of the radial base functions are estimated, the non-linear problem demands initial values. Additionally a line search is necessary to improve the convergence of the solution and a penalty method to fix the estimated parameters in a reasonable interval. The achieved accuracy and the numerical efforts are compared in a simulation for both systems of localizing functions.
AB - The satellite missions CHAMP and GRACE have been launched in 2000 and 2002 respectively, to determine the static and the time variable gravity field of the Earth. Usually, the gravity field, which is derived from the observations of the missions, is modeled by a sum of spherical harmonics. It turns out, however, that these global base functions are not able to represent all the local details of the data. This study demonstrates two methods of modeling the residual signal by localizing base functions. On the one hand, the radial base functions are used, on the other hand the Slepian functions, which are generated by orthogonalization of spherical harmonics on a subspace of the sphere. If fall parameters of the radial base functions are estimated, the non-linear problem demands initial values. Additionally a line search is necessary to improve the convergence of the solution and a penalty method to fix the estimated parameters in a reasonable interval. The achieved accuracy and the numerical efforts are compared in a simulation for both systems of localizing functions.
UR - http://www.scopus.com/inward/record.url?scp=42149162845&partnerID=8YFLogxK
M3 - Artikel
AN - SCOPUS:42149162845
VL - 133
SP - 120
EP - 129
JO - ZFV - Zeitschrift fur Geodasie, Geoinformation und Landmanagement
JF - ZFV - Zeitschrift fur Geodasie, Geoinformation und Landmanagement
SN - 1618-8950
IS - 2
ER -