Electronic chart position point data simplification method and system

Abstract

The invention discloses an electronic chart position point data simplification method and a system. The electronic chart position point data simplification method includes the following steps and modules: searching maximum and minimum values of position point latitude and longitude in a source chart file; setting reference points includes that setting a lower left corner of a chart as a reference point or a central point of the chart as the reference point; obtaining relative values, including projected coordinate relative values and latitude and longitude relative values, of relative reference points for all position point data in the source chart file, and recording the relative values into a system electronic navigational chart (SENC) of the system chart file. According to the electronic chart position point data simplification method and the system, number of bytes indicating the position point data is reduced, data precision is not reduced, and data amount of position points of the system chart file is reduced. Besides, when the system chart file is formed, projecting calculation of all position points is completed, the projecting calculation is saved when an electronic chart is displayed, and display speed of the electronic chart is favorable for being improved.

Description

technical field [0001] The invention relates to a method for representing position point data of an electronic chart, in particular to a simplified representation method and system for position point data of an electronic chart, belonging to the technical field of information processing. Background technique [0002] One of the functions of Electronic Chart System (ECS) and Electronic Chart Display and Information System (ECDIS) is to display electronic charts, whose data comes from Electronic Navigational Chart (ENC) files. The position point data is the data expressing the latitude and longitude in the spatial record in the electronic navigation chart file. The electronic chart display system usually reads the electronic nautical chart (ENC) as the source chart file, and processes it to form a system chart file (SENC) and stores it in the system hard disk, and then uses the system chart file to display the electronic chart. Since the position point data in the electronic ...

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Problems solved by technology

This patent does not involve the data processing and display of the electronic chart itself of the server and the client, and the method related to the display scale of the electronic chart to reduce the download of the ship track data on the client and improve the display speed of the client cannot be applied to improve the display speed of the client. The display speed of the electronic chart itself on the server and client side

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