scholarly journals Three-dimensional terrain elevation in airborne interferometric frequency-domain radar

2017 ◽  
pp. 4-9
Author(s):  
Borys Fedotov ◽  
Sergey Stankevich ◽  
Yevhen Tsvietkov
Keyword(s):  
Image Restoration ◽  
Frequency Domain ◽  
Numerical Algorithm ◽  
Horizontal Plane ◽  
Three Dimensional ◽  
Radar Image ◽  
Two Dimensional ◽  
Terrain Elevation ◽  
Performance Calculation

This paper is devoted to the method for a three-dimensional radar image restoration of terrain elevations using airborne two antenna interferometric frequency-domain radar. A method’s main feature is the parallel obtaining of two-dimensional frequencydomain spectra both of radar terrain echo and its derivative for next synthesizing. The architecture of such interferometric radar is proposed, and math equations for one’s performance calculation are presented. The numerical algorithm for the terrain elevations calculation over an arbitrary horizontal plane is developed.

FREQUENCY DOMAIN RECONSTRUCTION FOR PHOTO- AND THERMOACOUSTIC TOMOGRAPHY WITH LINE DETECTORS

2009 ◽  
Vol 19 (02) ◽  
pp. 283-306 ◽  
Author(s):  
MARKUS HALTMEIER
Keyword(s):  
Wave Equation ◽  
Frequency Domain ◽  
Boundary Data ◽  
Three Dimensional ◽  
Photoacoustic Tomography ◽  
Two Dimensional ◽  
Reconstruction Problem ◽  
Acoustic Data ◽  
Dimensional Wave ◽  
Frequency Domain Reconstruction

This paper is concerned with a version of photoacoustic tomography, that uses line shaped detectors (instead of point-like ones) for the recording of acoustic data. The three-dimensional image reconstruction problem is reduced to a series of two-dimensional ones. First, the initial data of the two-dimensional wave equation is recovered from boundary data, and second, the classical two-dimensional Radon transform is inverted. We discuss uniqueness and stability of reconstruction, and compare frequency domain reconstruction formulas for various geometries.

FIELD INDUCED PHASE TRANSITION FOR SUSPENSION OF MONOSIZED SPHERES

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2357-2363 ◽  
Author(s):  
S. MEN ◽  
A. MEUNIER ◽  
C. MÉTAYER ◽  
G. BOSSIS
Keyword(s):  
Phase Transition ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Horizontal Plane ◽  
Constant Pressure ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Ewald Summation ◽  
Dipolar System ◽  
Rotating Field

We have developed a new Ewald summation for a three-dimensional dipolar system with two-dimensional periodicity in a uniaxial field and a rotating field in a horizontal plane. Under a constant pressure and temperature, Monte Carlo simulation has been carried out; phase transitions are found and chainlike structure for a uniaxial field and monolayer or multilayer for rotating field are obtained, which are well consistent with experiments.

Part IV. An experimental study of the collapse of liquid columns on a rigid horizontal plane

1952 ◽  
Vol 244 (882) ◽  
pp. 312-324 ◽  
Keyword(s):  
Experimental Study ◽  
Horizontal Plane ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Circular Cylinders ◽  
Square Root ◽  
Two Dimensional

An experimental study has been made of some aspects of the phenomena accompanying the collapse of liquid columns on to a rigid horizontal plane with air as the outer medium. The cases covered include the two-dimensional collapse of rectangular and semicircular sections, and the three-dimensional axial collapse of right circular cylinders. As the columns collapsed, the fluid spread across the horizontal plane, attaining a maximum velocity, which, in the two-dimensional cases, was proportional to the square root of the original height. It was not clear whether this proportionality would hold for the axial collapse of cylinders. If it did, then the factor of proportionality would be some 25 % lower. In the two-dimensional cases the top of the residual column accelerated downwards to a maximum velocity proportional to the square root of the product of the original height and the original height to base ratio. The nature of the subsequent retardation indicated that the downward velocity probably approached zero asymptotically with time.

scholarly journals Three-dimensional space: locomotory style explains memory differences in rats and hummingbirds

2014 ◽  
Vol 281 (1784) ◽  
pp. 20140301 ◽  
Author(s):  
I. Nuri Flores-Abreu ◽  
T. Andrew Hurly ◽  
James A. Ainge ◽  
Susan D. Healy
Keyword(s):  
Horizontal Plane ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Vertical Component ◽  
Horizontal Component ◽  
Vertical Dimension ◽  
Three Dimensions ◽  
Two Dimensional ◽  
With Memory ◽  
Three Dimensional Space

While most animals live in a three-dimensional world, they move through it to different extents depending on their mode of locomotion: terrestrial animals move vertically less than do swimming and flying animals. As nearly everything we know about how animals learn and remember locations in space comes from two-dimensional experiments in the horizontal plane, here we determined whether the use of three-dimensional space by a terrestrial and a flying animal was correlated with memory for a rewarded location. In the cubic mazes in which we trained and tested rats and hummingbirds, rats moved more vertically than horizontally, whereas hummingbirds moved equally in the three dimensions. Consistent with their movement preferences, rats were more accurate in relocating the horizontal component of a rewarded location than they were in the vertical component. Hummingbirds, however, were more accurate in the vertical dimension than they were in the horizontal, a result that cannot be explained by their use of space. Either as a result of evolution or ontogeny, it appears that birds and rats prioritize horizontal versus vertical components differently when they remember three-dimensional space.

scholarly journals Modelling flows in shallow (fluvial) lakes with prevailing circulations in the horizontal plane: limits of 2D compared to 3D models

2016 ◽  
Vol 18 (6) ◽  
pp. 928-945 ◽  
Author(s):  
Andrea Fenocchi ◽  
Gabriella Petaccia ◽  
Stefano Sibilla
Keyword(s):  
Numerical Modelling ◽  
Driving Force ◽  
Horizontal Plane ◽  
Three Dimensional ◽  
Vertical Plane ◽  
3D Models ◽  
Northern Italy ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Gravity Driven

The numerical modelling of circulations in shallow lakes is a relevant tool for all environmental applications in which flow advection processes are of interest, e.g. for studies on nutrients, microorganisms, pollutants and sediment dynamics. While three-dimensional (3D) models are needed to properly describe the flow fields of basins with the main circulations in the vertical plane, two-dimensional (2D) models are commonly deemed to yield adequate results for lakes with prevailing horizontal circulations. However, the depth-averaged approximation is more limiting for wind-driven flows than for gravity-driven ones, such as rivers, as the driving force is a surface rather than a volume one, distributed along the depth through turbulence. In this work, the effects of such inaccuracy on the reproduction of circulation layouts are evaluated through compared simulations between a 2D Shallow Water solver and a 3D Reynolds-Averaged Navier-Stokes one. The models are first applied to a simple enclosed elliptical test basin and then to the real case of the Superior Lake of Mantua, a shallow fluvial lake in Northern Italy, thereby also investigating the influences of the interaction of wind with a riverine current and of a complex bathymetry on the compared results.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

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