A new technique in demodulation of normal modes - Archive ouverte HAL Access content directly
Journal Articles Physics of the Earth and Planetary Interiors Year : 1994

A new technique in demodulation of normal modes

(1) , (2)
1
2

Abstract

Lateral heterogeneities of the Earth produce amplitude modulations of the so-called unresolved multiplets. A spectral fitting technique based on the polynomial interpolation of Hermite allows the retrieval of these slowly varying modulation functions. No restrictive hypothesis on coupling among multiplets is necessary. Modulation functions are constrained in time within aQ-cycle for data with typical signal-to-noise ratios. Sensitivity to noise is reduced by the introduction of cosine tapers and by a priori information on the modulation functions. The method then damps rapid oscillations caused by noise and becomes stable. These amplitude modulations can be used in a first stage for inversions where both phase and amplitude are necessary, and generalize basic mode observables such as the local frequency.
Not file

Dates and versions

hal-03940029 , version 1 (15-01-2023)

Identifiers

Cite

Ramin Nawab, Philippe Lognonné. A new technique in demodulation of normal modes. Physics of the Earth and Planetary Interiors, 1994, 84 (1-4), pp.139-160. ⟨10.1016/0031-9201(94)90038-8⟩. ⟨hal-03940029⟩
0 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More