scholarly journals A Three-Dimensional Target Depth-Resolution Method with a Single-Vector Sensor

Sensors ◽  
2018 ◽  
Vol 18 (4) ◽  
pp. 1182 ◽  
Author(s):  
Anbang Zhao ◽  
Xuejie Bi ◽  
Juan Hui ◽  
Caigao Zeng ◽  
Lin Ma
Keyword(s):  
Three Dimensional ◽  
Depth Resolution ◽  
Resolution Method ◽  
Vector Sensor ◽  
Target Depth

scholarly journals Application and Extension of Vertical Intensity Lower-Mode in Methods for Target Depth-Resolution with a Single-Vector Sensor

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2073
Author(s):  
Anbang Zhao ◽  
Xuejie Bi ◽  
Juan Hui ◽  
Caigao Zeng ◽  
Lin Ma
Keyword(s):  
Depth Resolution ◽  
Lower Mode ◽  
Vector Sensor ◽  
Target Depth

Three-dimensional tomography using a soft X-ray holographic microscope and CCD camera

1998 ◽  
Vol 5 (3) ◽  
pp. 1088-1089 ◽  
Author(s):  
Norio Watanabe ◽  
Sadao Aoki
Keyword(s):  
Tungsten Wire ◽  
Three Dimensional ◽  
Numerical Aperture ◽  
Ccd Camera ◽  
Depth Resolution ◽  
Projection Data ◽  
Back Projection ◽  
X Ray ◽  
Dimensional Reconstruction ◽  
Transverse Resolution

The depth resolution of a soft X-ray hologram is much worse than its transverse resolution because a single soft X-ray hologram has a small numerical aperture. To obtain a three-dimensional image, in-line holograms of a specimen were recorded from various directions and reconstructed to obtain two-dimensional projection data. Then, a three-dimensional reconstruction was performed by back-projection of these reconstructed holograms. Three-dimensional images of a tungsten wire of diameter 10 µm and a fossil of a diatom were obtained.

Advanced visualization using image super-resolution method for three-dimensional mobile system

2021 ◽  
Vol 480 ◽  
pp. 126494
Author(s):  
Munkh-Uchral Erdenebat ◽  
Yan-Ling Piao ◽  
Ki-Chul Kwon ◽  
Moung Hee Lee ◽  
Ki Hoon Kwon ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Super Resolution ◽  
Mobile System ◽  
Resolution Method ◽  
Image Super Resolution ◽  
Advanced Visualization

scholarly journals A Vector Sensor-Based Acoustic Characterization System for Marine Renewable Energy

2020 ◽  
Vol 8 (3) ◽  
pp. 187
Author(s):  
Kaustubha Raghukumar ◽  
Grace Chang ◽  
Frank Spada ◽  
Craig Jones
Keyword(s):  
Renewable Energy ◽  
Three Dimensional ◽  
Acoustic Flow ◽  
Flow Noise ◽  
Vector Sensor ◽  
Acoustic Signature ◽  
Vector Sensors ◽  
Noise Measurements ◽  
Noise Data ◽  
Using Data

NoiseSpotter is a passive acoustic monitoring system that characterizes, classifies, and geo-locates anthropogenic and natural sounds in near real time. It was developed with the primary goal of supporting the evaluation of potential acoustic effects of offshore renewable energy projects. The system consists of a compact array of three acoustic vector sensors, which measures acoustic pressure and the three-dimensional particle velocity vector associated with the propagation of an acoustic wave, thereby inherently providing bearing information to an underwater source of sound. By utilizing an array of three vector sensors, the application of beamforming techniques can provide sound source localization, allowing for characterization of the acoustic signature of specific underwater acoustic sources. Here, performance characteristics of the system are presented, using data from controlled acoustic transmissions in a quiet environment and ambient noise measurements in an energetic tidal channel in the presence of non-acoustic flow noise. Data quality is demonstrated by the ability to reduce non-acoustic flow noise contamination, while system utility is shown by the ability to characterize and localize sources of sound in the underwater environment.

scholarly journals Frequency Invariant Beamforming for a Small-Sized Bi-Cone Acoustic Vector–Sensor Array

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 661
Author(s):  
Erzheng Fang ◽  
Chenyang Gui ◽  
Desen Yang ◽  
Zhongrui Zhu
Keyword(s):  
Sensor Array ◽  
Three Dimensional ◽  
Sensor Arrays ◽  
Signal Frequency ◽  
Acoustic Vector Sensor ◽  
Mechanical Coupling ◽  
Vector Sensor ◽  
Coupling System ◽  
Simulation Results ◽  
Vector Sensor Array

In this work, we design a small-sized bi-cone acoustic vector-sensor array (BCAVSA) and propose a frequency invariant beamforming method for the BCAVSA, inspired by the Ormia ochracea’s coupling ears and harmonic nesting. First, we design a BCAVSA using several sets of cylindrical acoustic vector-sensor arrays (AVSAs), which are used as a guide to construct the constant beamwidth beamformer. Due to the mechanical coupling system of the Ormia ochracea’s two ears, the phase and amplitude differences of acoustic signals at the bilateral tympanal membranes are magnified. To obtain a virtual BCAVSA with larger interelement distances, we then extend the coupling magnified system into the BCAVSA by deriving the expression of the coupling magnified matrix for the BCAVSA and providing the selecting method of coupled parameters for fitting the underwater signal frequency. Finally, the frequency invariant beamforming method is developed to acquire the constant beamwidth pattern in the three-dimensional plane by deriving several sets of the frequency weighted coefficients for the different cylindrical AVSAs. Simulation results show that this method achieves a narrower mainlobe width compared to the original BCAVSA. This method has lower sidelobes and a narrower mainlobe width compared to the coupling magnified bi-cone pressure sensor array.

scholarly journals Single-pixel three-dimensional imaging with time-based depth resolution

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Ming-Jie Sun ◽  
Matthew P. Edgar ◽  
Graham M. Gibson ◽  
Baoqing Sun ◽  
Neal Radwell ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Depth Resolution ◽  
Three Dimensional Imaging ◽  
Single Pixel

A novel direct resolution method for coupled systems in finite element analysis

2020 ◽  
Vol 39 (5) ◽  
pp. 1271-1280
Author(s):  
Youcef Boutora ◽  
Noureddine Takorabet
Keyword(s):  
Finite Elements ◽  
Linear Systems ◽  
Symmetric Matrix ◽  
Direct Method ◽  
Three Dimensional ◽  
Coupled Systems ◽  
Resolution Method ◽  
Element Analysis ◽  
Content Type ◽  
Magnetostatic Problem

Purpose This paper aims to propose a novel direct method for indefinite algebraic linear systems. It is well adapted for sparse linear systems, such as those of two-dimensional (2-D) finite elements problems, especially for coupled systems. Design/methodology/approach The proposed method is developed on an example of an indefinite symmetric matrix. The algorithm of the method is given next, and a comparison between the numbers of operations required by the method and the Cholesky method is also given. Finally, an application on a magnetostatic problem for classical methods (Gauss and Cholesky) shows the relative efficiency of the proposed method. Findings The proposed method can be used advantageously for 2-D finite elements in stepping methods without using a block decomposition of matrices. Research limitations/implications This method is advantageous for direct linear solving for 2-D problems, but it is not recommended at this time for three-dimensional problems. Originality/value The proposed method is the first direct solver for algebraic linear systems proposed since more than a half century. It is not limited for symmetric positive systems such as many of direct and iterative methods.

Optical Depth Profiling of Thin Films by Impulse Mirage Effect Spectroscopy. Part I: Theory

1994 ◽  
Vol 48 (9) ◽  
pp. 1054-1075 ◽  
Author(s):  
M. A. Schweitzer ◽  
J. F. Power
Keyword(s):  
Probe Beam ◽  
Fluid Layer ◽  
Three Dimensional ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Beam Deflection ◽  
Theoretical Expression ◽  
Mirage Effect ◽  
Photothermal Deflection ◽  
Effect Method

Impulse mirage effect/photothermal deflection spectrometry may be used to detect depth-dependent optical absorption in materials, through the time dependence of the probe beam deflection signal occurring in response to sample irradiation with a short excitation pulse. In this work a theoretical expression was derived for the normal and transverse photothermal deflection signals which occur in a sample with homogeneous thermal properties but where optical absorptivity varies with depth from the surface. An analytical solution of moderate simplicity is obtained for several cases of experimental interest, with three-dimensional heat conduction effects included. The depth profile resolution obtained with the mirage effect method is critically dependent on the distance between the sample layer probed and the offset position of the probe beam in the fluid layer above the sample. Saturation conditions and conditions for obtaining optimal depth resolution of continuous and discrete optical profiles are examined in detail.

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