Method for extracting effective net distribution length of acete chinensis net based on ship position data

Abstract

The invention relates to a method for extracting the effective net distribution length of an acete chinensis net based on ship position data, and the method comprises the following steps: dividing thebehaviors of each voyage of an acete chinensis net fishing boat into five stages, and dividing the fishing operation stage into three states; applying a jenks optimal natural fracture method to determine speed thresholds of anchoring net laying, waiting for fishing or stopping for rest, net hauling and fishing and rapid sailing states, SQL statements are applied to extract a point set of the fishing boat in the anchoring net laying state, and then a DBSCAN clustering algorithm is applied to extract the number of nets to which an anchoring net laying point set belongs; based on the longitude and latitude information, calculating the actual network distribution distance of the network by using a semi-versine formula; and calculating the actual effective net length of the net by combining the characteristics of the acete chinensis net and the correlation between the distances generated by all the nets under the net and the distance of the effective net distribution net length. Accordingto the method, the accuracy of extracting effective net distribution net lengths of different net numbers of the acete chinensis net can be improved, and a higher-precision method support is providedfor improving fishing effort quantification.

Description

technical field [0001] The invention belongs to the technical field of application of fishing boat position data, and in particular relates to a method for extracting effective net lengths of hairy shrimp nets based on ship position data. Background technique [0002] As the shrimp resources are facing a severe situation of decline, the fishing quota system has become an important guarantee for the sustainable development of the shrimp resources, and the calculation of fishing effort has become the key to the deep implementation of the fishing quota system. Vessel Monitoring System (VMS, Vessel Monitoring System) is a system that obtains vessel position data through satellites, and can provide positioning time, longitude and latitude information of fishing vessel position, speed and course information. Based on technologies such as the automatic ship identification system and the Beidou satellite ship position monitoring system, my country has initially realized the contact ...

AI Technical Summary

Problems solved by technology

However, although the net gear for hairy shrimp belongs to the type of stretching net, its structure is obviously different from other stretching nets. Its bycatch rate is low and its selectivity for hairy shrimp is extremely high. It is the exclusive net gear for fishing of hairy shrimp.

In addition, the effective length of nets for different nets will change with the actual production and fishing conditions, time and weather, sea environment and other conditions. significantly larger than

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