The Design And Implementation Of Automatic Configuration About The Electronic Chart Dynamic Note

With the development of charts from the origin of maps,paper maps are gradually transformed into electronic maps,and people's attention has gradually shifted from land to sea.With the rapid development of the shipping industry,the demand for nautical charts is becoming larger and larger.It is necessary for high-quality nautical charts to be developed.With the development of geographic information system,the electronic chart information system is gradually replaced the traditional paper chart.The difference between the ordinary map and the electronic chart is that the development of the electronic chart is relatively slow,and its audience is relatively narrow,leading to the speed of its development is slower than the electronic map.At the same time,the configuration algorithm in the electronic chart is relatively poor.Based on these,this paper did some research on the dynamic annotation configuration of the electronic chart.The main work of this paper is as follows:(1)Research background of the dynamic configuration of the electronic chart annotation was introduced,and the significance of studying the annotation configuration of the chart was clarified.The current research status of the dynamic annotation configuration of electronic chart was analyzed,and the configuration rules of topographic map and nautical chart were described in detail.Based on the comparison,the electronic map and electronic chart dynamic annotation features were put forward.The annotation configurations difference of charts and maps was summarized,and some research on electronic chart dynamic annotation configuration was done based on that.(2)The simplification of chart element vertex could greatly improve the efficiency of chart annotation configuration.Based on this,the existing simplification algorithms for linear element vertex were analyzed.The Douglas Peucker algorithm based on stack algorithm was applied to linear element vertex simplification.Starting from the linear element vertex simplification algorithm and combining area element annotation features,a simplification algorithm of area element vertex using shape segmentation was proposed.(3)According to the real-time update characteristics of the electronic chart display elements,a new annotation configuration algorithm for point elements,linear elements and area elements was designed.The annotation configuration of point elements in electronic chart was realized based on genetic algorithm.The annotation configuration of linear elements was implemented by taking a relatively monotonic segment annotation configuration.The traditional centerline method was improved to obtain more efficient and accurate annotation configuration for area elements.(4)C# language was used to encode the dynamic annotation configuration of charts.The database model of chart vertex storage was designed.Based on these,the annotation dynamic configuration of point elements,linear elements and area elements in electronic chart was realized.