Results 41 to 50 of about 2,333 (168)

Maximum Likelihood Deconvolution of Beamforming Images with Signal-Dependent Speckle Fluctuations

Remote Sensing
Ocean Acoustic Waveguide Remote Sensing (OAWRS) typically utilizes large-aperture linear arrays combined with coherent beamforming to estimate the spatial distribution of acoustic scattering echoes. The conventional maximum likelihood deconvolution (DCV)
Yuchen Zheng, Xiaobin Ping, Lingxuan Li, Delin Wang   +3 more
doaj   +1 more source

Seismo‐Acoustic Detection and Localization of Iceberg Collapse in Atka Bay, Antarctica

Geophysical Research Letters, Volume 52, Issue 23, 16 December 2025.
Abstract On 12 January 2022, an iceberg collapsed at the edge of frozen Atka Bay, Antarctica. The event generated seismic, hydroacoustic, and atmospheric infrasound waves recorded by a local network comprising land‐ and iceshelf‐based seismometers, an underwater hydrophone, and an on‐ice infrasound array.
G. Averbuch, A. Houstin, D. P. Zitterbart, J. Bonnel, J. A. Collins, J. D. Assink   +5 more
wiley   +1 more source

Compressive Matched-Field Processing

, 2011
Source localization by matched-field processing (MFP) generally involves solving a number of computationally intensive partial differential equations.
Mantzel, William, Romberg, Justin, Sabra, Karim   +2 more
core   +1 more source

Automatic Detection of the Number of Raypaths in a Shallow-Water Waveguide [PDF]

, 2013
International audienceCorrect identification and tracking of stable raypaths are critical for shallow-water acoustic tomography. Separating raypaths using high-resolution methods has been presented to improve resolution ability based on the prior ...
Jiang, Longyu, Mars, Jerome,
core   +3 more sources

D‐Region Changes and Wave Activity Detected From Unusually Strong VLF Anomalies Associated With the January 2022 Tonga Volcanic Eruption

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract We present unusually strong daytime signal amplitude anomalies of 11.1 dB on JJI and 12.6 dB on VTX very low‐frequency (VLF) transmitter signals recorded at Suva, Fiji, due to the powerful Hunga Tonga–Hunga Ha'apai (HTHH) volcanic eruption (VE) on 15 January 2022 around 04:00 UT.
Sushil Kumar, Sarwan Kumar, Mie Ichihara
wiley   +1 more source

Deblurring of Beamformed Images in the Ocean Acoustic Waveguide Using Deep Learning-Based Deconvolution

Remote Sensing
A horizontal towed linear coherent hydrophone array is often employed to estimate the spatial intensity distribution of incident plane waves scattered from the geological and biological features in an ocean acoustic waveguide using conventional ...
Zijie Zha, Xi Yan, Xiaobin Ping, Shilong Wang, Delin Wang   +4 more
doaj   +1 more source

Characterizing Fractured Zones in Urban Karst Geology Using Leaky Surface Waves From Distributed Acoustic Sensing

Journal of Geophysical Research: Solid Earth, Volume 130, Issue 7, July 2025.
Abstract Urban karst geology poses significant geohazard risks, most notably sinkholes and surface depression stemming from soluble and fractured bedrock that is prone to dissolution and collapse. However, mapping and characterizing these hazards using traditional geophysical surveys in cities is challenging due to dense infrastructure and high levels ...
Zhinong Wang, Tieyuan Zhu
wiley   +1 more source

Evaluating Numerical Weather Prediction Models in the Middle Atmosphere Using Coherent Oceanic Acoustic Noise Observations

Journal of Geophysical Research: Atmospheres, Volume 129, Issue 23, 16 December 2024.
Abstract We develop a method to assess numerical weather prediction (NWP) model performances from the mid‐stratosphere to the mesosphere‐lower thermosphere (∼ ${\sim} $30–120 km), through comparisons between observed and simulated amplitude of oceanic infrasound known as microbaroms.
P. Letournel, C. Listowski, M. Bocquet, A. Le Pichon, A. Farchi   +4 more
wiley   +1 more source

Surface Wave Development and Ambient Sound in the Ocean

Journal of Geophysical Research: Oceans, Volume 129, Issue 12, December 2024.
Abstract Wind, wave, and acoustic observations are used to test a scaling for ambient sound levels in the ocean that is based on wind speed and the degree of surface wave development (at a given wind speed). The focus of this study is acoustic frequencies in the range 1–20 kHz, for which sound is generated by the bubbles injected during surface wave ...
Jim Thomson, Jie Yang, Robert Taylor, E. J. Rainville, Kristin Zeiden, Luc Rainville, Samuel Brenner, Megan Ballard, Meghan F. Cronin   +8 more
wiley   +1 more source

Index to NASA Tech Briefs, 1975 [PDF]

, 1976
This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech ...

core   +1 more source