GEOSCAN, résultats de la recherche


TitreStochastic regularization: smoothness or similarity?
AuteurMaurer, H; Holliger, K; Boerner, D E
SourceGeophysical Research Letters vol. 25, no. 15, 1998 p. 2889-2892, (Accès ouvert)
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 1999095
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetslevés géophysiques; données sismiques; analyses du temps de parcours; modèles sismiques; géophysique; géomathématique
Illustrationsspectra; images; graphs
Diffusé1998 08 01
Résumé(disponible en anglais seulement)
Inversions of geophysical data often involve solving large?scale underdetermined systems of equations that require regularization, preferably through incorporation of a priori information. Since many natural phenomena exhibit complex random behavior, statistical properties offer important a priori constraints. Inversion constrained by model covariance functions, a form of stochastic regularization, is formally equivalent to imposing simultaneously the auxiliary constraints of (i) model correlation (smoothness) and (ii) similarity with a preferred model (damping). We show that a priori stochastic information defines uniquely the relative contributions of smoothing and damping, such that the higher the fractal dimension the greater the damping contribution. However, if the model discretization interval exceeds the characteristic scale length of the parameters to be resolved, stochastic regularization artificially reduces to only damping constraints.