scholarly journals QUANTITATIVE VALUES OF TARGET FEATURES ESTIMATION TECHNIQUE ACCORDING TO WIDEBAND RADAR SOUNDING

2019 ◽  
pp. 13-18
Author(s):  
E. L. Kapylov ◽  
V. V. Neyolov ◽  
A. A. Samorodov
Keyword(s):  
Evaluation Method ◽  
Radar Data ◽  
Data Matrix ◽  
Transform Method ◽  
Value Analysis ◽  
Radar Systems ◽  
Resolution Element ◽  
Scattering Centers ◽  
Wideband Radar ◽  
The Fourier Transform

In civil and special application radar systems broadband radar technologies are widespread. Electrodynamic computer simulation is used for development of modern radar systems. It’s important to study new effective ways of detailed radar image analysis for automatic radar identification. The conventional approach to a radar imaging and a data visualization is based on the Fourier transform method. This method has restrictions and it’s hard to identify close scattering centers because of a fan‑shaped structure. The paper considers a spectral evaluation method based on eigen value analysis of autocorrelation data matrix for processing broadband radar data. Radar length and intensity of scattering centers of a radar target are evaluated by MUSIC method. The main advantage is an ability to identify scattering centers within one resolution element (resel). In order to demonstrate the ability of the developed method broadband frequency characteristics of two typical radar targets are calculated. Intensity and relative distance of scattering center can be more over evaluated with a high accuracy. Stability testing of results to white noise is given.

scholarly journals Apparent Variation of v sin i and Rotational Modulation in Be Stars

2004 ◽  
Vol 215 ◽  
pp. 93-94
Author(s):  
C. Neiner ◽  
S. Jankov ◽  
M. Floquet ◽  
A. M. Hubert
Keyword(s):  
Fourier Transform ◽  
Magnetic Dipole ◽  
Be Stars ◽  
Line Profiles ◽  
Transform Method ◽  
Rotational Modulation ◽  
Be Star ◽  
Apparent Variation ◽  
The Fourier Transform ◽  
First Time

v sin i was determined by applying the Fourier transform method to the line profiles of two classical Be Stars. A variation is observed in the apparent v sin i which corresponds to the main frequencies associated to nrp modes. Rotational modulation is observed in wind sensitive UV lines of the Be star ω Ori and is associated with an oblique magnetic dipole which is discovered for the first time in a classical Be star.

Bleustein-Gulyaev Waves in an Inhomogeneous Layered Piezoelectric Half-Space

2006 ◽  
Vol 306-308 ◽  
pp. 1223-1228
Author(s):  
Fei Peng ◽  
Hua Rui Liu
Keyword(s):  
Fourier Transform ◽  
Phase Velocity ◽  
Half Space ◽  
Electric Potential ◽  
Piezoelectric Layer ◽  
Field Equations ◽  
Transform Method ◽  
Coupled Field ◽  
Coupled Field Equations ◽  
The Fourier Transform

The propagation of Bleustein-Gulyaev (BG) waves in an inhomogeneous layered piezoelectric half-space is investigated in this paper. Application of the Fourier transform method and by solving the electromechanically coupled field equations, solutions to the mechanical displacement and electric potential are obtained for the piezoelectric layer and substrate, respectively. The phase velocity equations for BG waves are obtained for the surface electrically shorted case. When the layer and the substrate are homogenous, the dispersion equations are in agreement with the corresponding results. Numerical calculations are performed for the case that the layer and the substrate are identical LiNbO3 except that they are polarized in opposite directions. Effects of the inhomogeneities induced by either the layer or substrate are discussed in detail.

Direct Part Mark Bar Code Image Preprocessing

2015 ◽  
Vol 7 (3) ◽  
pp. 13-24
Author(s):  
Lingling Li ◽  
Tao Gao ◽  
Yaoquan Yang
Keyword(s):  
Recognition Algorithm ◽  
Code Region ◽  
Data Matrix ◽  
Background Region ◽  
Vertical Projection ◽  
Transform Method ◽  
Color Processing ◽  
Low Contrast ◽  
Bar Code ◽  
Intensity Changes

Due to factors such as ambient light and metal materials, the collected industrial DPM bar code images may exist uneven illumination, low contrast, color of background area is darker than bar code region and other harsh issues, while the existing 2D code recognition device can only recognize the type which bar code area color is darker than background region. Therefore, the quality of preprocessing effect is the key point to subsequent recognition algorithm. In this paper, the homomorphic filtering method is used to weaken the influence of uneven illumination firstly, which will enhance the image contrast degree. Then do horizontal and vertical projection, find the points with greater intensity changes in both directions, make the image into blocks, again use the classic Kittler binarization algorithm on each block, then use mathematical morphology method to standardize the dot data matrix images. Finally, an improved Hough transform method is used to detect the ‘L' type finder pattern accurately, then find its pixel value, if color of the background region is darker than the bar code area, do invert-color processing. The processing results of a set of industrial DPM bar code images confirm the effectiveness of the proposed method.

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