The Analysis And Improvement Of Mechanism Of KML Language Under OpenSceneGraph Earth Platform

KML (Keyhole Markup Language) is an XML-based markup languagegeographic information, and its main role is to display geographic information. Itssyntax is simple and flexible scalability strong, has become an internationally acceptedstandards.At present, the Geographic Information System (GIS) have been applied tomarine resources, environment, health, transportation,agriculture, aviation,publicsecurity, city planning, natural disaster monitoring, and military fields. As long as itcomes to the application associated with geographic coordinates, GIS platforms arerequired as a base supporter. For different GIS platforms, to ensure compatibility fordifferent types of data is an important work to improve its generality.This paper is based on an open source project OSG Earth. The project is growingwell and have been noticed by the developers in the industry more and more. Thepaper mainly do the work to improve the KML module in this project. In addition, thepaper also implements a3D virtual Earth client, which can get image and elevationdata from the LAN.Firstly, this paper analyzes the work principle of OSG (OpenSceneGraph) projectto study the mechanism of its read and write functions, lay the foundation for later.Then, learning the mechanism of OSG Earth for loading and management filesfrom data source. Combined with the actual needs, the paper achieved a data sourceplugin to get data from a server on the LAN.Next, the paper describes in detail with the KML syntax specification, and makeimprovements for the KML module. In this paper just focused on the last twoimplementation details.Finally, the paper developed a3D virtual earth client. Besides the commonfeatures in most GIS client, the paper achieved the functions for the KML files tocreate, load, edit, delete and save. The client is running stable, and have a nice userexperience.