Метод дальнего обнаружения сформированных рыбных косяков маломощными низкочастотными просветными сигналами

• Main Authors: Шевченко, Е., Тахтеев, В., Стародубцев, П.
• Format: Text
• Language: unknown
• Published: Федеральное государственное унитарное предприятие «Тихоокеанский научно-исследовательский рыбохозяйственный центр» 2006
• Subjects: Sakhalin
• Online Access: http://cyberleninka.ru/article/n/metod-dalnego-obnaruzheniya-sformirovannyh-rybnyh-kosyakov-malomoschnymi-nizkochastotnymi-prosvetnymi-signalami; http://cyberleninka.ru/article_covers/4372296.png

Представлены физические основы, результаты численных и натурных исследований применения низкочастотного просветного метода для дальнего обнаружения акустически слабозаметных движущихся рыбных косяков. Physical background and results of numerical and experimental investigations are presented of the low frequency transmissive method using for distant detection of moving fish schools. These kind of schools are hard to detect by means of sonars, because increasing the distance requires substantial increase of their power, that leads to increased complexity of hydroacoustic systems and substantial disturbance of biological equilibrium. The proposed method of low-power and low-frequency transmissive signals allows to detect fish concentrations at a distance of several hundred kilometers. The method is based on the phenomenon of water perturbation around moving schools. Transmissive signal interacts with the perturbed water volume that results in phase modulation of the signal. Additional harmonics appear which could be used for detection a presence of the schools. The impacts of moving fish schools and natural turbulence of water environment in distortion of transmissive acoustic signals are modeled. Besides, results of field experiments with tonal signals at the hydroacoustic barrier between Sakhalin and Iturup islands are analyzed. Methodology of a hydroacoustic system designing for monitoring in offshore waters and its technical parameters are discussed.