caa a22 4500 475813227 CHVBK 20180406123803.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/PL00001129 doi (NATIONALLICENCE)springer-10.1007/PL00001129 Localized Denoising Filtering Using the Wavelet Transform [Elektronische Daten] [M. Fedi, L. Lenarduzzi, R. Primiceri, T. Quarta] —Gravity and magnetic signals are usually affected by noise, which is in turn related either to the geological heterogeneity of the shallow structures or to the measurement and data processing procedures. Along the map, the signal is represented by field anomalies which overlap with the noise in a variable and complicated way. Classical filtering techniques such as the Fourier (band-pass) filtering or the wavelet "cycle-spinning” method denoise the data only in a global sense and are therefore inaccurate when the frequency content of the signal is no longer uniform. We propose instead a localized denoising of such data, based on localized filtering techniques using the wavelet transform. The localized denoising filtering is based on a "soft thresholding” rule and is characterized by a local thresholding parameter (LTP). An adaptive tuning of the LTP parameter allows enhancement of the high frequencies of the signal and is effective to remove the noise as much as possible. The method is confronted using two different kinds of wavelets, namely the biorthogonal and the multiscale shiftable transforms and is applied to the noisy vertical derivative of the gravity field of Sicily. The technique proves to be superior to classical methods and may be similarly applied to any manner of geophysical data. Birkhäuser Verlag Basel,, 2000 Key Words: Threshold, denoising, filtering, wavelet, multiresolution, potential field nationallicence Fedi M. Dipartimento di Geofisica e Vulcanologia, Università di Napoli Federico II, Largo San Marcellino, 10 C.A.P. 80138 Napoli, Italia; E-mail: fedi@unina.it, IT aut Lenarduzzi L. CNR I.A.M.I. (Istituto per le Applicazioni della Matematica e dell'Informatica), Via Ampère, 56, C.A.P. 20131 Milano, Italia; E-mail: licia@iami.mi.cnr.it, IT aut Primiceri R. Dipartimento di Scienza dei Materiali Ex-Collegio Fiorini, Via per Arnesano, C.A.P. 73100 Lecce, Italia; E-mail: rita@axpmatl.unile.it, IT aut Quarta T. Dipartimento di Scienza dei Materiali Ex-Collegio Fiorini, Via per Arnesano, C.A.P. 73100 Lecce, Italia; E-mail: quarta@axpmat.unile.it, IT aut https://doi.org/10.1007/PL00001129 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00001129 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fedi M. Dipartimento di Geofisica e Vulcanologia, Università di Napoli Federico II, Largo San Marcellino, 10 C.A.P. 80138 Napoli, Italia; E-mail: fedi@unina.it, IT aut NATIONALLICENCE 700 1- Lenarduzzi L. CNR I.A.M.I. (Istituto per le Applicazioni della Matematica e dell'Informatica), Via Ampère, 56, C.A.P. 20131 Milano, Italia; E-mail: licia@iami.mi.cnr.it, IT aut NATIONALLICENCE 700 1- Primiceri R. Dipartimento di Scienza dei Materiali Ex-Collegio Fiorini, Via per Arnesano, C.A.P. 73100 Lecce, Italia; E-mail: rita@axpmatl.unile.it, IT aut NATIONALLICENCE 700 1- Quarta T. Dipartimento di Scienza dei Materiali Ex-Collegio Fiorini, Via per Arnesano, C.A.P. 73100 Lecce, Italia; E-mail: quarta@axpmat.unile.it, IT aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer