scholarly journals Three-Dimensional ISAR Imaging Method for High-Speed Targets in Short-Range Using Impulse Radar Based on SIMO Array

Sensors ◽  
2016 ◽  
Vol 16 (3) ◽  
pp. 364 ◽  
Author(s):  
Xinpeng Zhou ◽  
Guohua Wei ◽  
Siliang Wu ◽  
Dawei Wang
Keyword(s):  
High Speed ◽  
Short Range ◽  
Three Dimensional ◽  
Imaging Method ◽  
Isar Imaging

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

scholarly journals Squint Model InISAR Imaging Method Based on Reference Interferometric Phase Construction and Coordinate Transformation

2021 ◽  
Vol 13 (11) ◽  
pp. 2224
Author(s):  
Yu Li ◽  
Yunhua Zhang ◽  
Xiao Dong
Keyword(s):  
Coordinate Transformation ◽  
Cross Correlation ◽  
Three Dimensional ◽  
Image Distortion ◽  
Imaging Method ◽  
Phase Ambiguity ◽  
Correlation Algorithm ◽  
Interferometric Phase ◽  
Isar Imaging

The imaging quality of InISAR under squint geometry can be greatly degraded due to the serious interferometric phase ambiguity (InPhaA) and thus result in image distortion problems. Aiming to solve these problems, a three-dimensional InISAR (3D ISAR) imaging method based on reference InPhas construction and coordinate transformation is presented in this paper. First, the target’s 3D coarse location is obtained by the cross-correlation algorithm, and a relatively stronger scatterer is taken as the reference scatterer to construct the reference interferometric phases (InPhas) so as to remove the InPhaA and restore the real InPhas. The selected scatterer needs not to be exactly in the center of the coarsely located target. Then, the image distortion is corrected by coordinate transformation, and finally the 3D coordinates of the target can be accurately estimated. Both simulation and practical experiment results validate the effectiveness of the method.

High Speed Micro Holographic PIV Measurements of Microorganisms

2008 ◽  
Author(s):  
M. Zarzecki ◽  
F. J. Diez
Keyword(s):  
Velocity Field ◽  
High Speed ◽  
Fourier Transforms ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Imaging Method ◽  
Time Resolved ◽  
Feeding Methods ◽  
Holographic Particle Image Velocimetry ◽  
Three Components

Holographic particle image velocimetry (PIV) is a novel application of holography that allows for tracking of small particle sized objects in a small volume. Whereas regular PIV allows for the two in-plane components of the velocity field to be measured, and stereoscopic PIV allows for the three-components of the velocity field to be measured in a thin plane, holographic PIV allows for the three-components of the velocity to be measured for each individual particle present in the measuring volume, thus allowing to fully resolve fluid flows that are inherently 3D in nature. There are many examples of three dimensional flows in nature including turbulence flows, but another very interesting application very well suited for this technique involves tracking living microorganisms in order to study their motion and their means of propulsion. As part of this research a micro organism was tracked in three dimensions using a high speed microscopic holographic imaging method. The ability to track organisms in 3D allows better understanding and characterizing of their behavior including their propulsion methods, their feeding methods and their interaction with each other. The time resolved holograms were reconstructed in Matlab using Fast Fourier Transforms. A laser pointer was used as a source of coherent light, and a high speed PIV camera (Photron APX Ultima) was used to capture the images. A beam expander was used to increase the diameter of the laser beam allowing for a larger tracking area. Results with this system will show the trajectories in 3D of microorganisms as well as the three components of the velocity field showing the interaction of the organisms with their environment.

4716369 High speed imaging method with three-dimensional NMR

1988 ◽  
Vol 6 (5) ◽  
pp. VIII
Author(s):  
Kensuke Sekihara ◽  
Shigeru Matsui ◽  
Hideki Kohno ◽  
Etsuji Yamamoto ◽  
Hidemi Shiono
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Imaging Method ◽  
High Speed Imaging

scholarly journals Bistatic ISAR Sparse Imaging Method for High-Speed Moving Target Based on Dechirping Processing

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Chuangzhan Zeng ◽  
Weigang Zhu ◽  
Xin Jia
Keyword(s):  
High Speed ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Posteriori Probability ◽  
Imaging Method ◽  
Moving Target ◽  
Geometric Correction ◽  
Distortion Factor ◽  
A Posteriori Probability ◽  
Isar Imaging

Bistatic inverse synthetic aperture radar (ISAR) can increase the probability of tracking the high-speed target and provide more angle information than monostatic ISAR. However, bistatic ISAR suffers from a serious defocusing problem, resulting from the high-speed motion. Furthermore, the inherent geometry distortion and calibration problems make bistatic ISAR (B-ISAR) imaging more complex. In response to these problems, we propose a bistatic ISAR imaging method for high-speed moving target with geometric distortion correction and calibration based on dechirping processing. At first, based on the motion decomposition idea, the B-ISAR echo model of the high-speed moving target is established. Then, by analyzing the imaging mechanism of the Range-Doppler algorithm (RDA), we eliminate the phase items influencing the imaging quality with speed compensation and Doppler compensation. After that, the analytic formula of the geometric distortion factor and calibration factor are deduced, which helps transform the geometric correction and calibration problem into a parameter estimation problem. Finally, with the sparsity of the scattering points, the required parameters are solved using the expectation maximization (EM) algorithm based on the maximum a posteriori probability criterion. With the estimated parameters, a clear B-ISAR image of a high-speed moving target with geometric correction and calibration is obtained. The simulations show that the proposed method has a better resolution and simultaneously attains geometric correction and calibration of the image.

ISAR imaging of high-speed moving targets in short-range using impulse radar

2015 ◽  
Vol 26 (5) ◽  
pp. 964-972 ◽  
Author(s):  
Xinpeng Zhou ◽  
Guohua Wei ◽  
Dawei Wang ◽  
Xu Wang ◽  
Siliang Wu
Keyword(s):  
High Speed ◽  
Short Range ◽  
Moving Targets ◽  
Isar Imaging

scholarly journals Three-dimensional Multicolor Subcellular Imaging by Fast Serial Sectioning Tomography for Centimeter-scale Specimens

2021 ◽  
Author(s):  
Wentao Yu ◽  
Lei Kang ◽  
Victor T. C. Tsang ◽  
Yan Zhang ◽  
Ivy H. M. Wong ◽  
...  
Keyword(s):  
High Speed ◽  
3D Imaging ◽  
Uv Light ◽  
Three Dimensional ◽  
Biological Information ◽  
Imaging Method ◽  
Tissue Preparation ◽  
Layer By Layer ◽  
Autofluorescence Imaging ◽  
Double Labeling

Rapid multicolor three-dimensional (3D) imaging for centimeter-scale specimens with subcellular resolution remains a challenging but captivating scientific pursuit. Here, we present a fast, automated, cost-effective, and versatile multicolor 3D imaging method with ultraviolet (UV) surface excitation and vibratomy-assisted sectioning, termed translational rapid ultraviolet-excited sectioning tomography (TRUST). TRUST enables exogenous molecular-specific fluorescence and endogenous content-rich autofluorescence imaging simultaneously with the help of a UV light-emitting diode and a color camera. Commonly applied tissue preparation procedures (e.g., staining or clearing) are laborious, time-consuming, and may induce detrimental effects on processed samples. In TRUST, formalin-fixed specimens are stained with real-time double labeling layer by layer along with serial widefield optical illumination with raster scanning and mechanical sectioning to improve the staining speed and reveal rich biological information. All vital organs in mice have been imaged by TRUST to demonstrate its fast, robust, and high-content multicolor 3D imaging ability. Moreover, its potential for developmental biology has also been validated by imaging entire mouse embryos (taking ~2 days for imaging the embryo at the embryonic day of 15). TRUST offers a way for multicontrast and multicolor whole-organ 3D imaging with high resolution and high speed while relieving researchers from heavy sample preparation workload.

scholarly journals Optical Coherence Tomography Angiography

2019 ◽  
Vol 2 (1) ◽  
pp. 46-54
Author(s):  
Dita Mintardi ◽  
AK Ansyori ◽  
Ramzi Amin
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Optical Coherence Tomography Angiography ◽  
Three Dimensional ◽  
Imaging Method ◽  
Optical Coherence ◽  
Cross Sectional ◽  
En Face ◽  
Capillary Plexus ◽  
Oct Imaging

Optical Coherence Tomography Angiography (OCTA) is a new high-resolution imaging method for visualizing retinal and choroidal circulation without any dye injection By detecting intravascular flow quickly when needed and being able to repeat images, as often as needed, without risk to patients, doctors will value OCTA as one of the most important applications of OCT imaging because of its ability to offer precise visualization of intravascular flow in the inner retina layer and outside, as well as the inner choroid. OCTA uses high-speed structural OCT imaging and provides three-dimensional data about microvascular structures, enabling visualization of the en face apart from the retinal capillary plexus and choriocapillaris, combined with co-registered en face and cross-sectional structural OCT. Although OCTA is a strong modality, it can have imaging artifacts and provide information that is inherently more complex than structural OCT alone. Successful interpretation of OCTA findings requires an understanding of how OCTA works, the relationship of various ocular pathologies to its angiographic features, and integrated assessment of angiographic and structural OCT data.

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