Acoustic source inversion to estimate volume flux from volcanic explosions

Conditional inversion to estimate parameters from eddy-flux observations

Aims Data assimilation is a useful tool to extract information from large datasets of the net ecosystem exchange (NEE) of CO2 obtained by eddy-flux measurements. However, the number of parameters in ecosystem models that can be constrained by eddy-flux data is limited by conventional inverse analysis that estimates parameter values based on one-time inversion. This study aimed to improve data a...

Acoustic Multi-source Waveform Inversion with Deblurring

The theory of preconditioned multi-source waveform inversion is presented where many shot gathers are simultaneously back-propagated to form the multisource gradient of the misfit function. Synthetic tests on 2D Marmousi model data show that multi-source waveform inversion using an encoded multi-source deblurring filter as a preconditioner can provide a good inverted model but with less computa...

Generation and Propagation of Infrasonic Airwaves from Volcanic Explosions

Analysis of infrasonic pressure waves generated by active volcanoes is essential to the understanding of volcanic explosion dynamics. Unlike seismic waves propagating in the earth, infrasonic airwaves offer a relatively unfiltered representation of source motions at the vent during an eruption. Time-varying acoustic propagation filters caused by changeable atmospheric conditions are minimal for...

Acoustic to articulatory inversion

The context of this work is speech analysis. The subject deals with acoustic-to-articulatory inversion, i.e. the recovery of the temporal evolution of the vocal tract shape from the signal. This topic is important because it is likely to give rise to applications in the domains of speech coding as well as second language learning. Acoustic-to-articulatory inversion relies on an analysis by synt...

Application of the Monopole Source to Quantify Explosive Flux During Vulcanian Explosions at Sakurajima Volcano (Japan)