The fast contour deformation method for calculating the high frequency scattered field from the Fock current on the convex scatterer

2015 ◽  
Author(s):  
Yu Mao Wu ◽  
Weng Cho Chew ◽  
Li Jun Jiang
Keyword(s):  
Scattered Field ◽  
High Frequency ◽  
Deformation Method ◽  
Contour Deformation

High frequency diffraction by a soft circular disc

1972 ◽  
Vol 71 (3) ◽  
pp. 527-543
Author(s):  
J. C. Newby
Keyword(s):  
Integral Equation ◽  
Scattered Field ◽  
High Frequency ◽  
Circular Disc ◽  
Single Function ◽  
Contour Deformation ◽  
Axis Of Symmetry

AbstractThe problem is governed by a Jones integral equation and the solution is shown to depend upon a single function which occurs naturally after a contour deformation has produced extensive cancellation in the work. The far-scattered field off the axis of symmetry is found in detail, yielding terms which are believed to be new.

Correlation analysis of radio-auroral scatter signals

1970 ◽  
Vol 48 (14) ◽  
pp. 1716-1723 ◽  
Author(s):  
F. H. Palmer ◽  
D. R. Moorcroft
Keyword(s):  
Correlation Analysis ◽  
Drift Velocity ◽  
Scattered Field ◽  
High Frequency ◽  
Very High Frequency ◽  
Drift Speed ◽  
Scale Size ◽  
Spaced Antennas ◽  
Very High ◽  
East West

Very high frequency radio-auroral scatter signals are regularly observed on an Ottawa–London (Ontario) backscatter circuit operating at 40.35 MHz. For three of these events the scale size and drift velocity of the scattered field at the receiving site were determined by a correlation analysis of the signals received at spaced antennas. The overall east–west extent of the scattering regions was determined from the scale-size measurements. At least two types of event were observed. One type results from scattering by extended regions with horizontal dimensions greater than 200 km and having minimum drift velocities of a few hundred m/s. The second type of event results from simultaneous scattering by a number of independent regions, each having its own drift speed and direction. These regions have drift velocities in excess of 1 km/s and horizontal dimensions often less than 30 km.

scholarly journals AN EFFICIENT NUMERICAL CONTOUR DEFORMATION METHOD FOR CALCULATING ELECTROMAGNETIC SCATTERED FIELDS FROM 3-D CONVEX SCATTERERS

2017 ◽  
Vol 158 ◽  
pp. 109-119
Author(s):  
Yu Mao Wu ◽  
Weng Cho Chew ◽  
Ya-Qiu Jin ◽  
Tie-Jun Cui ◽  
Li Jun Jiang
Keyword(s):  
Deformation Method ◽  
Contour Deformation ◽  
Scattered Fields

scholarly journals Application of Asymptotic and Rigorous Techniques for the Characterization of Interferences Caused by a Wind Turbine in Its Neighborhood

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Jesús Algar ◽  
Lorena Lozano ◽  
Javier Moreno ◽  
Iván González ◽  
Felipe Cátedra
Keyword(s):  
Wind Turbine ◽  
Method Of Moments ◽  
Scattered Field ◽  
High Frequency ◽  
Wind Farms ◽  
Uniform Theory Of Diffraction ◽  
Spline Surfaces ◽  
Radio Systems ◽  
Geometrical Theory Of Diffraction

This paper presents a complete assessment to the interferences caused in the nearby radio systems by wind turbines. Three different parameters have been considered: the scattered field of a wind turbine, its radar cross-section (RCS), and the Doppler shift generated by the rotating movements of the blades. These predictions are very useful for the study of the influence of wind farms in radio systems. To achieve this, both high-frequency techniques, such as Geometrical Theory of Diffraction/Uniform Theory of Diffraction (GTD/UTD) and Physical Optics (PO), and rigorous techniques, like Method of Moments (MoM), have been used. In the analysis of the scattered field, conductor and dielectric models of the wind turbine have been analyzed. In this way, realistic results can be obtained. For all cases under analysis, the wind turbine has been modeled with NURBS (Non-Uniform Rational B-Spline) surfaces since they allow the real shape of the object to be accurately replicated with very little information.

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