No abstract

The issues discussed in this paper provide for further development of studies in the sphere of imaging spectroscopy and laser vision. In terms of forming the information fields (radiation fields), the electro-optical systems are subdivided into the passive and active ones. Passive electro-optical systems use the information fields formed by natural radiation sources, whereas the active ones suggest using artificial sources. Comparative analysis of mathematical and physical issues of designing the electro-optical systems with dynamic spectral processing of optical radiation of the passive and active types has been performed. It has been shown that the controlled dynamic spectral processing of optical radiation can be implemented within the passive and active electro-optical systems on the basis of the same algorithm that represents operation of the optical processor performing the mathematical operation of dot product. The authors have developed the block diagram of an active electro-optical system with dynamic spectral processing. The algorithm for optimal detection of optical signals has been developed using basics of the signal detection theory. Mathematical modeling of target detection against an inhomogeneous background has been performed. It has been shown that the optimal dynamic spectral processing of optical radiation in active electro-optical system enables to separate the desired optical signal by suppressing the background signal.

The article deals with the experimental study of the compensation method for atmospheric attenuation of laser radiation in active electro-optical remote sensing systems with dynamic spectral processing of optical signals that provides an increase of target image contrast. The compensation method for atmospheric attenuation of laser radiation in active electro-optical systems consists in forming the spectral intensity of the probing radiation not only on the basis of a priori data on the spectral features of the reflecting surfaces of the target and the background, but also taking into account the spectral transmittance of the optical radiation propagation medium. The experimental setup has been developed, in which the source of radiation in the transmitting part of the electro- optical system is three semiconductor lasers operating in the ranges of the red, green and blue parts of the spectrum. Absorption light filters were used in the experiment as elements simulating the spectral properties of the reflecting surfaces of the target and background. The cuvettes with a liquid absorbing optical radiation were used as elements simulating atmospheric attenuation.

This paper describes the compensation method for atmospheric attenuation of laser radiation, which can be implemented in active electro-optical systems with pre-detector dynamic spectral processing of optical signals. In these electro-optical systems, the spectral flux of sensing radiation is formed using multispectral laser signals based on a priori information about the spectral reflectance of the target and background. The sensing signal formed in this way ensures maximum suppression of the background signal at the output of system with minimal attenuation of the target signal. The influence of atmospheric radiation attenuation on operation of an active electro-optical system with dynamic spectral processing has been analyzed. It has been shown that the laser radiation attenuation in the atmosphere significantly affects the efficiency of dynamic spectral processing of optical signals (leads to a decrease in the target image contrast). The developed compensation method for atmospheric attenuation of radiation in active electro-optical systems with dynamic spectral processing is based on the fact that the spectral intensity of the sensing radiation is formed not only on the basis of a priori data on spectral characteristics of the target and background, but also takes into account the spectral transmittance of the optical radiation propagation medium.