scholarly journals Increase the contrast of the image of objects in the active optoelectronic system with dynamic spectral processing of optical emitting

2020 ◽  
Vol 3 (59) ◽  
pp. 122-126
Author(s):  
O. Cherkashyna
Keyword(s):  
Light Emission ◽  
Block Diagram ◽  
A Priori ◽  
Spectral Characteristics ◽  
Optical Signal ◽  
Matched Filtering ◽  
A Priori Information ◽  
Spectral Processing ◽  
Optoelectronic System ◽  
Priori Information

The article discusses a method for increasing the contrast of images in an optoelectronic system based on active dynamic spectral matched filtering. The principles of constructing active optoelectronic systems with matched filtering are based on the fact that the optical system uses a set of amplitude-controlled radiation sources operating in different parts of the spectral range as emitting sources. It is essential that the energy composition of the light emission control signals is formed on the basis of a priori information about the characteristics of the target and the background, so as to reduce the value of the spectral components of the optical signal reflected from the surface belongs to the background and with minimal attenuation of the signal intensity belonging to the object. The method assumes the presence of a set of a priori information about the spectral characteristics of the background and the object to form the instrumental function for controlling the amplitude of emitting sources. The analysis of the mathematical and physical aspects of systems with dynamic spectral processing of active type optical emitting is made. It is shown that an active optoelectronic system with dynamic spectral processing can be considered as an analog processor for calculating the dot product of a vector by a vector. One of the factors is the reflection coefficient from a surface with a priori known characteristics, and the second is a dimmable multispectral signal. A block diagram of an optoelectronic system with dynamic spectral processing of optical emitting with active formation of the information field in order to increase the contrast of the object image has been developed. The goal of the article is to develop the mathematical and physical foundations for constructing an active optoelectronic system with dynamic spectral processing of optical emitting in order to increase the image contrast.

Algorithms for automatic detection and recognition of low contrast radar objects using noise-like broadband signals

2021 ◽  
Author(s):  
E.V. Egorova ◽  
A.N. Ribakov ◽  
M.Kh. Aksayitov
Keyword(s):  
Spectral Methods ◽  
Block Diagram ◽  
A Priori ◽  
Original Method ◽  
Optimal Algorithms ◽  
A Priori Information ◽  
Low Contrast ◽  
Priori Information ◽  
Detection And Recognition

An algorithm for automatic detection and recognition of low-contrast ground targets using noise-like broadband signals and the use of combined processing of radar signals against the background of interference is presented; the proposed original method for processing signals from airborne objects during their detection and determination of their coordinates synthesizes optimal algorithms for detecting radar objects in the case of a priori information about useful signals and interference, as well as the ability to determine the range and speed of movement; the block diagram of the mathematical model of signal processing is considered on the basis of the developed algorithms for identifying stationary targets against the background of local objects by the radar portrait, as well as by the envelope of the radar signal; the results of testing mathematical modeling of the algorithm for recognizing signals from stationary targets and a forest with an equal probability of the appearance of these targets in the analyzed space are presented. The results of domestic theoretical and experimental research today characterize the main areas of research in the field of detection and recognition of various radar objects. The main research tool of most works is the search and development of promising mathematical models of objects and the modeling of secondary radiation for their recognition, which in some cases allows obtaining additional information about these objects. Correlation and spectral methods of their processing are currently being considered in relation to the noise sounding signal of a radar station. This article analyzes the application of correlation and spectral methods in processing noise signals with the identification of the disadvantages and advantages of each of the methods; the functioning of the block diagram of the known single-channel noise radar stations with sequential spectral processing of the total signal is considered. The proposed original method for processing signals from airborne objects during their detection and determination of their coordinates synthesizes optimal algorithms for detecting targets in the case of a priori information about useful signals and interference, as well as the ability to determine the distance and speed of movement. It should be noted the promising application of combined processing of radar signals against the background of interference, taking into account simultaneously the spatial, polarization, temporal and frequency features of the signals reflected from objects. With regard to the problem of recognizing the shape of objects, both in Russia and abroad, intensive work is being carried out to improve the resolution of on-board radars with a synthesized broadband antenna array, while raising the range resolution and increasing the angular resolution allow obtaining long-range portraits of these objects, as well as seeing them. elements and obtain images of targets. In the study of methods for detecting radar objects based on Gaussian noise signals with a large base, it is shown that such signals are promising for detecting subtle objects at ranges greater than with conventional monopulse radar. When receiving noise signals with a large base, spectral methods of signal extraction turn out to be more advantageous in comparison with the known correlation method of signal processing. Based on the use of noise signals, recognition of ground and air objects is realized, while the method of long-range portraits can have an advantage over the envelope method. Based on the results of mathematical modeling, the possibility of automatic recognition of stationary ground objects by two different methods was confirmed with a high probability of their recognition.

Resolution Enhancement of Composite Spectra with Fractal Noise in Derivative Spectrometry

2000 ◽  
Vol 54 (5) ◽  
pp. 721-730 ◽  
Author(s):  
S. S. Kharintsev ◽  
D. I. Kamalova ◽  
M. Kh. Salakhov
Keyword(s):  
A Priori ◽  
Resolution Enhancement ◽  
Numerical Differentiation ◽  
A Priori Information ◽  
Experimental Ir ◽  
Composite Spectra ◽  
Self Similar ◽  
Priori Information ◽  
Fractal Noise ◽  
Derivative Spectrometry

The problem of improving the resolution of composite spectra with statistically self-similar (fractal) noise is considered within the framework of derivative spectrometry. An algorithm of the numerical differentiation of an arbitrary (including fractional) order of spectra is produced by the statistical regularization method taking into account a priori information on statistical properties of the fractal noise. Fractal noise is analyzed in terms of the statistical Hurst method. The efficiency and expedience of this algorithm are exemplified by treating simulated and experimental IR spectra.

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