| 摘要 |
FIELD: underwater acoustics. SUBSTANCE: method can be recommended for fish search, detection and direction finding systems. Shoals of fish and individuals can be detected by signals of their vital activities. Processing of underwater acoustic signals is carried out by way of parallel spectral analysis over n frequency subchannels with subsequent performance of adaptive change of levels of signals in each frequency subchannel. After this converter signals are compared with threshold values, signals exceeding threshold are indicated. Direction to hydrobionts is determined in case of equality of readings of indicators of both reception channels. Device for direction finding to hydrobionts has unit of spatially separated receivers, two amplifiers, analog-to-digital converter, unit of threshold elements and register. It is supplemented with two spectrum analyzers, four units measuring r.m.s. values of signals, unit of paired averaging of r.m.s. signals in like subchannels, unit determining minimal level of signals, unit determining weight coefficients, first and second units of controlled attenuators, unit determining average value of normalized signals, unit setting thresholds, first and second units of threshold elements, first and second units of adders, first and second units of filters. EFFECT: increased accuracy of direction finding and noise immunity. 4 dwg |
