Statistical model and analysis of two-scale modification of conical scanning direction finding method

2019 ◽  
pp. 45-51
Author(s):  
A. A. Bludov ◽  
G. A. Gorbatovsky ◽  
V. S. Pavlov
Keyword(s):  
Cross Section ◽  
Signal To Noise Ratio ◽  
Positional Information ◽  
Direction Finding ◽  
Elliptical Cross ◽  
Scanning Direction ◽  
Statistical Analysis Method ◽  
Scanning Frequency ◽  
Analytical Expressions ◽  
Finding Method

Statistical analysis method and its results are presented for a two-scale modification of the conical scanning direction finding method generalizing it for a case of elliptical cross-section of antenna beam. In order to utilize additional positional information that is excluded in a typical implementation of conical scan method, a two-scale procedure is proposed for estimating the direction to object. It is shown, that application of this procedure does not lead to worsening of the accuracy of object’s coordinates estimate near boresight axis and also attains a significant increase of angular operating area of direction finding due to the increase in number of harmonics of conical scanning frequency included in processing. Analytical expressions are obtained and discriminator and fluctuation curves are calculated, revealing the possibilities to increase the angular operating area of direction finding depending on signal-to-noise ratio and ellipticity of antenna beam’s cross-section.

scholarly journals Optimization of Direct Direction Finding Method with Two-Dimensional Correlative Processing of Spatial Signal

2018 ◽  
Vol 8 ◽  
pp. 46-53
Author(s):  
Vitaliy V. Tsyporenko ◽  
Valentyn G. Tsyporenko
Keyword(s):  
Main Parameter ◽  
Noise Immunity ◽  
Signal To Noise Ratio ◽  
Direction Finding ◽  
High Accuracy ◽  
Signal To Noise ◽  
High Noise ◽  
Spatial Shift ◽  
Simulation Results ◽  
Finding Method

In this article, the main parameter of the correlative-interferometric direction finding method with twodimensional correlative processing of spatial signal in the aperture of a linear antenna array (AA) is determined as the value of spatial shift within the AA aperture. The corresponding objective function is also formed. Analytical optimization of this parameter is presented and a comparative analysis of analytical calculations based on simulation results is conducted. In the simulation, a range of dependencies of the middle square deviation of estimation of direction on the value of the spatial shift for a signal-to-noise ratio of 0 dB, for minimum 3-sample and 4-sample Blackman-Harris windows of the spectral analysis, is received. The value of the middle square deviation of estimation of direction will be minimal and will equal 0.02 degrees using a minimum 3-sample Blackman-Harris window with the −67 dB level of side lobes. It offers high noise immunity and high accuracy of direction finding.

Numerical study of precession of circulating particles in tokamaks

2011 ◽  
Vol 77 (4) ◽  
pp. 559-569 ◽  
Author(s):  
O. S. BURDO ◽  
YA. I. KOLESNICHENKO ◽  
S. SIPILÄ ◽  
YU. V. YAKOVENKO
Keyword(s):  
Cross Section ◽  
Numerical Study ◽  
Circular Cross Section ◽  
Interpolation Formula ◽  
Plasma Pressure ◽  
Precession Frequency ◽  
Magnetic Shear ◽  
Elliptical Cross ◽  
Reasonable Approximation ◽  
Analytical Expressions

AbstractThe toroidal precession of circulating particles in tokamaks is studied numerically. The dependence of the precession frequency on the magnetic shear, the elongation of the plasma cross-section, and plasma pressure is investigated. It is concluded that the analytical expressions for the precession frequency by Kolesnichenko et al. (2003 Phys. Plasmas10, 1449–1457) represent a reasonable approximation for the limit cases of tokamaks with circular cross-section and shearless tokamaks with elliptical cross-section. The precession frequency was calculated for non-circular tokamaks with magnetic shear. Based on the numerical results, an interpolation formula for the precession frequency is proposed.

Use of Monopulse Difference-Phase Direction Finding Method for Location of Air Targets in Active-Passive Systems with Noise-Like Signal

2005 ◽  
Vol 63 (10) ◽  
pp. 863-869 ◽  
Author(s):  
Ye. N. Belov ◽  
Ye. M. Zarichnyak ◽  
V. I. Lutsenko ◽  
I. V. Lutsenko ◽  
V. G. Yakovlev
Keyword(s):  
Direction Finding ◽  
Passive Systems ◽  
Phase Direction ◽  
Finding Method

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

Saint–Venant torsion of anisotropic elliptical bar

2017 ◽  
Vol 45 (3) ◽  
pp. 286-294 ◽  
Author(s):  
István Ecsedi ◽  
Attila Baksa
Keyword(s):  
General Solution ◽  
Cross Section ◽  
Elliptical Cross Section ◽  
Elliptical Cross

The object of this article is the Saint–Venant torsion of anisotropic, homogeneous bar with solid elliptical cross section. A general solution of the Saint–Venant torsion for anisotropic elliptical cross section is presented and some known results are reformulated. The case of non-warping cross section is analysed.

scholarly journals The Tidal Potential of a Homogeneous Torus with an Elliptical Section of the Sleeve

2016 ◽  
Vol 25 (3) ◽  
Author(s):  
B. P. Kondratyev ◽  
N. G. Trubitsyna
Keyword(s):  
Cross Section ◽  
Kuiper Belt ◽  
Analytical Form ◽  
Elliptical Cross Section ◽  
External Region ◽  
Elliptical Cross ◽  
Tidal Potential ◽  
Gravitational Model ◽  
Elliptical Section

AbstractIn this paper the problem of the tidal potential of a homogeneous gravitating torus with an elliptical cross-section sleeve is solved. In particular, the potentials in analytical form in the vicinity of the center of the torus and its external region are found. This torus can serve as a gravitational model of the Kuiper belt.

Stresses and Deformations of Toroidal Shells of Elliptical Cross Section: With Applications to the Problems of Bending of Curved Tubes and of the Bourdon Gage

1952 ◽  
Vol 19 (1) ◽  
pp. 37-48
Author(s):  
R. A. Clark ◽  
T. I. Gilroy ◽  
E. Reissner
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Practical Interest ◽  
Closed Shell ◽  
Open Shell ◽  
Elliptical Cross Section ◽  
Axially Symmetric ◽  
Elliptical Cross ◽  
Two Parameters ◽  
Toroidal Shells

Abstract This paper is concerned with the application of the theory of thin shells to several problems for toroidal shells with elliptical cross section. These problems are as follows: (a) Closed shell subjected to uniform normal wall pressure. (b) Open shell subjected to end bending moments. (c) Combination of the results for the first and second problems in such a way as to obtain results for the stresses and deformations in Bourdon tubes. In all three problems the distribution of stresses is axially symmetric but only in the first problem are the displacements axially symmetric. The magnitude of stresses and deformations for given loads depends in all three problems on the magnitude of the two parameters bc/ah and b/c where b and c are the semiaxes of the elliptical section, a is the distance of the center of the section from the axis of revolution, and h is the thickness of the wall of the shell. For sufficiently small values of bc/ah trigonometric series solutions are obtained. For sufficiently large values of bc/ah asymptotic solutions are obtained. Numerical results are given for various quantities of practical interest as a function of bc/ah for the values 2, 1, 1/2, 1/4 of the semiaxes ratio b/c. It is suggested that the analysis be extended to still smaller values of b/c and to cross sections other than elliptical.

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