This paper describes a low profile inductive surface for High Frequency Surface Wave Radars (HFSWR). The longterm operating frequency band considered is High Frequency (HF). In this paper we will only discuss L-band in order to simplify the manufacturing phase and the proof of concept. A compact thin 2D Super Inductive Surface (SIS) based on printe...
A numerical model is proposed to compute the eigenmodes and the forcedresponse of multilayered elastic spheres. The main idea is to describe analyti-cally the problem along the angular coordinates with spherical harmonics andto discretize the radial direction with one-dimensional finite elements. Theproper test function must be carefully chosen so ...
Published in Scientific Reports
Surface waves emitted after large earthquakes are known to induce atmospheric infrasonic waves detectable at ionospheric heights using a variety of techniques, such as high frequency (HF) Doppler, global positioning system (GPS), and recently over-the-horizon (OTH) radar. The HF Doppler and OTH radar are particularly sensitive to the ionospheric si...
Over the past decade, ambient seismic noise has been used successfully to monitor various geological objects with high accuracy. Recently, it has been shown that surface seismic waves propagating within a sea dike body can be retrieved from the cross-correlation of ambient seismic noise generated by sea waves. We use sea wave impacts to monitor the...
44th Annual Review of Progress in Quantitative Nondestructive Evaluation, PROVO, ETATS-UNIS, 16-/07/2017 - 21/07/2017
Le diagnostic des structures et l'évaluation de leur durée de vie est une problématique importante pour le génie civil. La première couche de béton, appelée béton d'enrobage, qui protège les armatures d'acier de la corrosion, est particulièrement soumise aux dégradations. Parmi les méthodes de contrôle non destructif, les ondes mécaniques ont un fo...
In this paper, the propagation of both longitudinal and surface waves will be investigated within the scope of seismic measurements recorded along the circumference of concave structures. The underlying objective herein is to recover, in a non-destructive manner, the mechanical material properties from seismic refraction as well as multiple-channel...
The 1996 June 1 Tianzhu (Mw=5.2, Ms=4.9) and the 1995 July 21 Yongden (Mw=5.6, Ms=5.4) earthquakes are the two largest events recorded in the last 10 years between the 1990 October 20 Ms=5.8 and the recent 2000 June 6 Ms=5.6 earthquakes near the `Tianzhu seismic gap' on the Haiyuan fault in northeastern Tibet. We use frequency-time analysis (FTAN) ...
Array analysis is performed on surface waves recorded in the French Alps using a small-aperture (25km) temporary array of six broad-band stations. The analysis shows that both Rayleigh and Love waves deviate relative to the great-circle path. The deviations are particularly strong, up to 30°, between 20 and 40s period. To interpret these observatio...
Germany
