Fish acoustic target strength measurement device

Abstract

The invention relates to a fish acoustic target strength measurement device, which is provided with a water tank. The inner side of the water tank is provided with an arc guide rail which is matched with a pulley, and the pulley is provided with a clinometer and an energy converter. A dial is flatly arranged above the water tank, and a center hole of the dial is provided with a rotating shaft the lower end of which is connected with a level rotation pole. The lower part of the level rotation pole is connected with a connector, and the emission surface of the energy converter points to the center of the arc guide rail. In measurement, a tested fish is hung below the level rotation pole to be positioned at the center of the arc guide rail. A middle sliding wheel is driven, the pulley is adjusted to a needed incident sound wave angle, and the value of the incident sound wave angle is read by the clinometer. The rotating shaft is rotated to change the horizontal angle of the tested fish, and the horizontal angle is read by the dial. By receiving the size of a fish echo rating, the device measures the target strength value of different fishes in different incident directions. The device has the advantages of easy use, good operation, easy control, simple integral structure and low manufacturing cost.

Description

technical field [0001] The invention relates to an acoustic target strength measuring device, which is especially suitable for measuring the acoustic target strength of fish in different directions. Background technique [0002] The target intensity of the fish refers to the ratio of the intensity of the reflected sound wave to the intensity of the incident sound wave at a distance of one meter away from the acoustic center of the fish when the sound wave radiates to the fish. It is generally described in decibel notation, that is, the comparison value is magnified by 10 times after logarithmic operation. Since the density of the fish school (mantissa in unit volume) can be estimated by the ratio of the echo intensity of the fish school to the fish target intensity when the fixed-frequency sound wave is used to radiate the fish school, the fish target intensity is the fishery resource Important parameter for acoustic evaluation. [0003] Since the target strength of fish i...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem that the existing fish body target strength measurement cannot obtain the spatial pointing characteristics of the fish body target strength, the present invention provides a device for measuring the target strength in the experimental tank, which can measure individual fish in different directions The target intensity measurement of the fish target intensity is obtained to obtain the three-dimensional space pointing characteristics of the fish target intensity

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