The geometry of the Mach cone produced by a supersonic source is analyzed and mapped into initial conditions used in acoustic ray tracing. The resulting source model is combined with spherical geometry ray tracing methods to enable propagation simulations for infrasonic signals produced by bolides, space debris, rockets, aircraft, and other fast-than-sound sources out to typical infrasonic observation distances of hundreds or thousands of kilometers. Idealized linear and parabolic trajectories typical of bolides and rockets, respectively, are used to demonstrate the calculation of regional infrasonic signals produced by such sources and characteristics of the radiated infrasonic waves are found to vary strongly with the geometry of the trajectory and atmospheric structure. Predicted regional infrasonic signals are compared with those observed from a November 2020 bolide that passed over Scandinavia using a combination of institutionally maintained infrasound stations and "citizen scientist" data from the Raspberry Shake data repository.
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http://dx.doi.org/10.1121/10.0025025 | DOI Listing |
J Acoust Soc Am
December 2024
Department of Physics, Naval Postgraduate School, 833 Dyer Road, Monterey, California 93943-5216, USA.
Deploying acoustic sensors on free-flying, long-living balloons helps to reach the areas not accessible with the traditional ground-based sensors, reduce flow noise, and improve characterization of various infrasound sources. Instrumented balloons can potentially increase the infrasonic detection range and early warning lead time for natural hazards. Balloons are also considered as platforms for planetary exploration.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
October 2024
Division of Mechanics and Acoustics, National Institute of Metrology, Beijing 100029, People's Republic of China.
On 13-15 January 2022, the Hunga Tonga-Hunga Ha'apai underwater volcano erupted. This powerful eruption generated infrasonic waves with amplitudes of thousands of Pascals in the near field. The ground infrasonic stations in China, located approximately 10 000 km from the Hunga volcano, also received waves with frequencies from 0.
View Article and Find Full Text PDFJ Acoust Soc Am
March 2024
Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
The geometry of the Mach cone produced by a supersonic source is analyzed and mapped into initial conditions used in acoustic ray tracing. The resulting source model is combined with spherical geometry ray tracing methods to enable propagation simulations for infrasonic signals produced by bolides, space debris, rockets, aircraft, and other fast-than-sound sources out to typical infrasonic observation distances of hundreds or thousands of kilometers. Idealized linear and parabolic trajectories typical of bolides and rockets, respectively, are used to demonstrate the calculation of regional infrasonic signals produced by such sources and characteristics of the radiated infrasonic waves are found to vary strongly with the geometry of the trajectory and atmospheric structure.
View Article and Find Full Text PDFJ Acoust Soc Am
January 2024
Atomic Weapons Establishment (AWE) plc., Reading, RG7 4PR, United Kingdom.
The evolution of observed dominant frequencies from a high-intensity infrasonic pulse with receiver range and stratospheric temperature is investigated using direct numerical simulations of the two-dimensional unsteady compressible Navier-Stokes equations. There is a high level of uncertainty in estimating source dominant frequencies based on received signals at sparse points on the ground. Nonlinear propagation effects in the ground-level thermospheric arrivals are found to significantly alter dominant frequency measurements compared to stratospheric arrivals with smaller amplitude sources.
View Article and Find Full Text PDFFront Neural Circuits
January 2024
Departamento de Neurociencia, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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