recordings of ambient noise or microtremors are increasingly used to find valuable information on soil in one dimension at a given site. ambient vibrations, which are assumed to be mainly composed of surface waves, can be used to determine the surface wave dispersion curve in order to retrieve shear wave velocity profile. in this regard, microtremors are usually recorded simultaneously in an ar...

A planar hard-dielectric Fabry-Pérot (FP) optical ultrasound sensor was modelled analytically to study how different wave modes affect the directionality. The sensor was modelled as a multilayered structure using the global matrix method. Modal dispersion curves were extracted from the model to enable features of the directional response to be linked to specific wave phenomena. The analytical m...

The analysis of ambient vibrations represents a valuable tool in seismic microzonation, engineering seismology, and other fields. An extensively used approach for the study of ambient vibrations is the use of array processing techniques. We have developed a novel technique for the analysis of the seismic wave field and show an application to the analysis of ambient vibrations. We derived maximu...

Determining the thickness of Europa's outer ice shell is a key factor for understanding internal dynamics, evolution, and potential habitability. As such, one primary goals any future lander mission to Europa would be constrain confirm presence global subsurface ocean. Tidally induced fracturing events provide natural source seismic energy illuminate subsurface, thus instrument onboard could pr...

A combined synthesis, experiment, and theory approach, using elastic and inelastic helium atom scattering along with ab initio density functional perturbation theory, has been used to investigate the vibrational dynamics and band structure of a recently synthesized organic-functionalized semiconductor interface. Specifically, the thermal properties and lattice dynamics of the underlying Ge(111)...

Traditional approaches of using dispersion curves for S-wave velocity reconstruction have limitations, principally, the 1D-layered model assumption and automatic/manual picking curves. At same time, conventional full-waveform inversion (FWI) can easily converge to a non-global minimum when applied directly complicated surface waves. Alternatively, recently introduced wave equation spectrum meth...

The dispersion of a coupled resonator optical waveguide made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the inherent dispersive cavity mode profile; i.e., the mode wave function depends on the driving frequency, not the eigenfrequency....

Time-frequency representations, like the spectrogram or the scalogram, are widely used to characterize dispersive waves. The resulting energy distributions, however, suffer from the uncertainty principle, which complicates the allocation of energy to individual propagation modes (especially when the dispersion curves of these modes are close to each other in the time-frequency domain). This res...