Using KML data for dynamic map updates
Keyhole Markup Language, or KML, is a format developed by Google for providing geospatial information. The KML format defines data for the display of geographic geometries like areas or lines.
KML has the ability to define a remote data source to be used for updates. This allows it to be used in place of other traditional data transmission systems such as DDS. KML can be used to supply dynamically updated imagery that can from simple track data more complex shapes or imagery.
What makes KML a truly useful format is the fact that it’s a markup language that can be composed at run-time from dynamic data sets, so you can, for example use the results of a database query to render KML entities for display on a map.
As a markup language, KML also defines styles inside KML data blocks, which means that visual attributes like line weights, color, and transparency can be modified dynamically, so you can, for example change parameters like the colors of tracks and weather areas as conditions change. This also allows for thinner clients, as the work of updating shape data and styles can be done server side.
The server can also control the rate at which updates are retrieved – allowing for a single point of control for your application’s update metrics.
In our TerraLens SDK, Kongsberg Geospatial has developed a system for displaying KML from a remote source, as a means of displaying track data that needs to be updated.
The KML View system can handle updating retrieving and processing updates autonomously from the application containing it, making it a low-effort means of adding dynamic information displays. By making use of the KML update feature, only the data that has changed needs to be updated. It’s thread safe and relies on non-blocking operations to ensure that it does not interrupt the rest of your application’s work flow.
Additional information about the TerraLens SDK can be found on the product specifications page.