Results 31 to 40 of about 26,633 (306)

Transfer of autocollimator calibration for use with scanning gantry profilometers for accurate determination of surface slope and curvature of state of the art x ray mirrors [PDF]

, 2019
X ray optics, desired for beamlines at free electron laser and diffraction limited storage ring x ray light sources, must have almost perfect surfaces, capable of delivering light to experiments without significant degradation of brightness and coherence.
Anderson, K., Dickert, J., Geckeler, R., Just, A., Lacey, I., Siewert, F., Smith, B., Yashchuk, V.   +7 more
core   +2 more sources

Spectral Acoustic Fingerprints of Sand and Sandstone Sea Bottoms

Journal of Marine Science and Engineering, 2022
Modern studies which dealt with the frequency domain analysis showed that a frequency-domain approach has an essential advantage and mentioned an inner qualitative relationship between the subsurface structure and its frequency spectra.
Uri Kushnir, Vladimir Frid
doaj   +1 more source

Sub-bottom Profiling Algorithm using Parametric Array

Journal of Ocean Engineering and Technology, 2014
In this paper, we propose an threshold-based Schur algorithm for estimating the media characteristics of sub-bottom multi-layers by using the signal generated by a parametric array transducer. We use the KZK model to generate a parametric array signal, and use the proposed threshold-based Schur algorithm for estimating the reflection coefficients of ...
Chong Hyun Lee, Jaeil Lee, Jinho Bae
openaire   +2 more sources

The Invincible (1758) site: an integrated geophysical assessment

, 1998
Chirp sub-bottom profiler and repeat sidescan sonar imaging of the Invincible wreck site (1758) in the Solent (U.K.), interpretation, and implications for management of the ...
Adams, Jonathan R., Bull, Jonathan M., Dix, Justin K., Quinn, Rory   +3 more
core   +1 more source

Observations of the daytime boundary layer in deep alpine valleys [PDF]

, 2006
Peer ...
Chemel, C., Chollet, J.P.
core   +3 more sources

Validation of Thorpe-scale-derived vertical diffusivities against microstructure measurements in the Kerguelen region [PDF]

Biogeosciences, 2014
The Thorpe scale is an energy-containing vertical overturning scale of large eddies associated with shear-generated turbulence. This study investigates indirect estimates of vertical diffusivities from the Thorpe scale method in the polar front region ...
Y.-H. Park, J.-H. Lee, I. Durand, C.-S. Hong   +3 more
doaj   +1 more source

Distinguish seabed objects utilizing different marine acoustic techniques

Egyptian Journal of Petroleum, 2021
The marine acoustic techniques are powerful tools to investigate and identify the seabed objects by applying different processing and interpretation steps.
Amr Z. Hamouda, Mohamed A. Nassar, Suzan M. El-Gharabawy   +2 more
doaj   +1 more source

Discharge estimation in a backwater affected meandering river [PDF]

, 2011
Variable effects of backwaters complicate the development of rating curves at hydrometric measurement stations. In areas influenced by backwater, single-parameter rating curve techniques are often inapplicable.
Hidayat, H., Hoitink, A.J.F., Sassi, M.G., Torfs, P.J.J.F., Vermeulen, B.   +4 more
core   +4 more sources

Inversion of the physical properties of seafloor surface sediments based on AUV sub-bottom profile data in the northern slope of the South China Sea

Scientific Reports, 2021
Based on the seafloor reflection coefficient obtained from autonomous underwater vehicle (AUV) sub-bottom profile survey data of the northern slope of the South China Sea, combined with the sample test data of seafloor surface sediments, we use the Biot ...
Qingjie Zhou, Xishuang Li, Bigui Huang, Lejun Liu, Shan Gao, Hang Zhou, Jie Liu, Baohua Liu, Chengyi Zhang   +8 more
doaj   +1 more source

A Novel Sub-Bottom Profiler Seabed Sediment Classification Method Based on BPNN With Biot-Stoll Model and Attenuation-Based Model

IEEE Access, 2021
The exploitation and utilization of seabed sediments provide vital significance in many fields. Recently, the classification of seabed sediments using sub-bottom profiler(SBP) data has become a research focus.
Mingke Li, Quan Tao, Guangchao Hou, Jingsheng Zhai   +3 more
doaj   +1 more source