Tool of the Trade: Google Earth Circles

Every day we use maps in dispatch, they’re one of our most valuable tools. But customizing them to the needs we have for a specific call can be difficult. CAD mapping functions are usually primitive at best and high end GIS software is far beyond the use of a communications center. A good compromise is Google Earth. It allows users to quickly plot points, draw polygons, add labels, print maps, and share their data. Information can even be exported and added to a regular Google Map that can be accessed by any device or web browser. This is a great resource for tracking large scale searches, visualizing the extent of an incident, or managing resources.

But a big limitation is Google Maps native inability to draw circles around a point. We can use circles to define an area covered by a cell phone ping, display an evacuation radius, or estimate the distance a person can travel in a gievn time. One of the simpilist ways to create these objects is through third party websites. These sites will create the circle and allow you to download it in a KML (Google’s map file type) and add it to your map. In reality these aren’t truce circles, rather a series of tiny line segments in a polygon. There are also plug-ins for Google Earth that add the functionality to the software. Our two favorites are:

FreeMapTools has a function where you enter the desired radius and center point and the site will create your circle. You simply click “Generate KML” to save the file and add it to Google Earth. The site allows you to customize the look and label for the rings as well. (There are a lot of great tools on the site, but that’s for a different post)


RINGS is a plug-ins for Google Earth that allows you to draw rings and sections of rings on Google Earth.