Electronic chart position point data simplification method

Abstract

The invention discloses an electronic chart position point data simplification method, which comprises the following steps of: 1, dividing chart position points into three types, namely point chart layer discrete position points, line chart layer continuous position points and surface chart layer continuous position points, and respectively processing the three types of chart layer position pointdata; 2, for the discrete position point data of the point graph layer, the discrete position points are continued according to a distance or byte rule, a reference position point of each position point is determined, and then each position point is represented by a relative coordinate relative to the reference position point; and 3, for the line and surface layer data, processing the initial position points of all the line segments according to the step (2), taking the midpoint of two adjacent position points as a reference position point for each group of continuous position points, and representing the line and surface layer position points by using the relative coordinates relative to the reference position point. And 4, storing the relative coordinate data, and generating an electronic chart file. The electronic chart precision is maintained, the chart file is greatly simplified, the storage space is reduced, and the processing efficiency is improved.

Description

technical field [0001] The invention relates to electronic chart vector data processing, in particular to a method for simplifying electronic chart position point data represented by relative position points, and belongs to the technical field of information processing. Background technique [0002] Vector electronic chart (ENC) is an electronic chart produced according to the "Digital Hydrographic Data Transmission Standard" (S-57 Standard) promulgated by the International Hydrographic Organization (IHO), and is an electronic chart information and display system (ECDIS). It provides basic data support for ship navigation, route planning, ocean management and many other fields. System vector electronic chart (SENC) is a database generated by the developer after unpacking ENC from S-57 and in a custom format, which can be directly read by ECDIS. The processing and reading of ENC is a necessary process of ECDIS, and its reading efficiency is related to the overall performance...

AI Technical Summary

Problems solved by technology

Patent No. CN103106281A "A Method and System for Simplifying Electronic Chart Position Point Data" is to reduce the number of data bytes by selecting the only standard point and then calculating the reference value of all other position points. This method only selects one The reference point makes the long-distance reference value larger. On the other hand, it does not take into account the layered structural characteristics of the chart file, and the simplification effect is poor; The D-P algorithm is used in the part, and the layer-by-layer simplification method is used in the concave part to reduce the number of points, so as to achieve the purpose of simplifying the data of the chart file and solve the problem of self-intersection of the graph. However, reducing the position points will inevitably affect the accuracy of the chart; The Chinese patent "A Thinning Method for S57 Chart Data" with the authorization number CN106528622A also reduces the number of position points and sacrifices the accuracy of the chart data in exchange for processing efficiency

Images