HR: 0800h
AN: GP31A-0830 [Abstracts]
TI: Wavelet Frames: an Alternative to Spherical Harmonic Representation of Potential Fields?
AU: Chambodut, A
EM: chambodu@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, Place Jussieu, Paris, 75005
France
AU: Panet, I
EM: panet@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, Place Jussieu, Paris, 75005
France
AU: Panet, I
EM: panet@ipgp.jussieu.fr
AF: Institut Geographique National, 6/8, Avenue Blaise Pascal, Marne-la-Vallee, 77455
France
AU: * Mandea, M
EM: mioara@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, Place Jussieu, Paris, 75005
France
AU: Diament, M
EM: diament@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4, Place Jussieu, Paris, 75005
France
AU: Holschneider, M
EM: hols@math.uni-potsdam.de
AF: Universitat Potsdam, 10, Am Neuen Palais, Potsdam, 14469
Germany
AU: Jamet, O
EM: olivier.jamet@ign.fr
AF: Universitat Potsdam, 10, Am Neuen Palais, Potsdam, 14469
Germany
AB:
Potential fields are classically represented on the sphere using spherical harmonics. However, this decomposition leads to
strong numerical difficulties when dealing with regional features. To overcome this drawback, we developed a new
representation of the magnetic and the gravity fields based on wavelet frames. We describe how to build a wavelet frame on
the sphere. The chosen frames are based on the Poisson multipoles wavelets, which are of special interest for geophysical
modelling, since their scaling parameter is linked to the multipole depth (Holschneider et al., 2003). Our first results in
representing the Earth's core magnetic and gravity fields from data evenly or unevenly distributed prove the interest of such
a representation. The comparison of the obtained wavelet models with spherical harmonic models underlines the superiority
of wavelets when dealing with globally, unevenly distributed datasets or regional ones.
DE: 1532 Reference fields (regional, global)
DE: 1545 Spatial variations (all harmonics and anomalies)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting