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Underwater vision among existing surveillance systems plays an important role. With it, you can solve many problems in places such as emergency rescue operations, work at great depths, the study of the seabed and minerals. The development of such systems and methods of their use should be based on a fairly universal theory of visual and instrumental vision, which allows predicting the potential capabilities of optical systems of various types depending on the characteristics of the object of observation, the location of the vision system (underwater, surface), the nature of lighting (natural, artificial), optical parameters of water and atmosphere, severity of excitement, etc. The development of this theory was initiated by research on the problem of visual visibility in water under natural light. Subsequently, the issues of instrumental observation came to the fore. Their solution required, on the one hand, the development of a rather complicated section of the theory of radiation transfer), and on the other hand, the development of a qualitatively new approach to the analysis of the image formation process (based on the results of the theory of signals and noise). The usual method used to detect an underwater target is to send and receive some form of acoustic energy. But speakers have limitations in resolution and range accuracy; while the potential benefits of laser detection of underwater targets include high directivity, high sensitivity and high range accuracy. Lasers operating in the blue-green region of the light spectrum (420: 570 nm) have several applications in the field of detection and determination of the range of immersed targets due to the minimum attenuation in water (less than 0.1 m-1) and the maximum laser reflection from the calculated targets (e.g. mines or submarines) to provide early warning. The laser response from various targets (metal, plastic, wood and rubber) is detected using a high resolution CCD camera. The position of the detection camera is adjusted to provide laser radiation with high reflection from the target and noise with low backscattering from the aquatic environment, digital image processing methods are also used to detect and distinguish echo signals from a metal target and subtract echo signals from other objects. The image of the target is extracted from the scattering noise using the methods of background subtraction and edge detection. Thus, it is possible to obtain high image quality and distinguish objects in troubled waters, which systems using acoustic waves cannot allow.
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