Measuring method for round-up space of purse seine

Abstract

The invention provides a measuring method for a round-up space of a purse seine. A depth finder, a protractor and an infrared distancer are adopted. The measuring method is characterized by comprising the steps that the depth finder is fixed to a foot line, and the sedimentation depth of a foot line closing point is actually measured; the infrared distancer measures the spacing distance between a floating ball and a seine ship; the protractor measures the purse line water entry angle; the spatial position of the foot line closing point is determined by applying the purse line water entry angle and the sedimentation depth of the foot line closing point; a catenary equation of netting of any portions of the purse seine is solved by applying the horizontal spacing distance between the floating ball and the ship body and the spatial position of the foot line closing point; the horizontal spacing distance between the netting at any water depth and the foot line closing point when the foot line is closed is calculated according to a curve equation. Accurate estimation data is supplied to purse seine operation performance evaluation, the problem that measurement of the round-up space of the purse seine is difficult is solved, and net operation performance optimization study is facilitated.

Description

technical field [0001] The invention relates to space measurement technology for purse seine encirclement. Background technique [0002] Lighting seines started in the 1960s and have been one of the main fishing gears for the utilization of pelagic fish resources until today; they have outstanding features such as high efficiency, energy saving, and low labor intensity. The estimation of the encirclement space of the net gear is an important parameter for the evaluation of the performance of the seine operation. Due to the structure of the net gear, the trajectory of the net release and the unbalanced shrinkage of the net clothes in different parts caused by the winding of the net, when the lower line is closed, the type of the seine net It is not a regular hemisphere, and due to the large main scale of the seine, it is very difficult to directly measure the seine encirclement space. Up to now, there are no relevant research reports on the estimation of the seine encirclemen...

AI Technical Summary

Problems solved by technology

[0005] The outstanding feature of the present invention is to adopt depth sounder, protractor, infrared ray range finder, obtain seine encirclement spatial measurement characterizing parameter, apply enclosing outline water entry angle and the subsidence depth of lower outline closing point, determine the space position of lower outline closing point; Using the horizontal distance between the floating ball and the hull and the spatial position of the closing point of the lower line, solve the catenary equation of the net at any part of the seine; according to the curve equation, estimate the net at any water depth and the closing point of the lower line when the lower line is closed The horizontal spacing provides accurate estimation data for the performance evaluation of the seine operation, solves the problem of difficult measurement of the seine encirclement space, and promotes the research on the performance optimization of the net gear

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