Circle Generator

Generate KML LineString, Polygon and MultiGeometry Circles

Description

KML Circle showing the 6,000 Km coverage of the Pechora Radar Station on Google Earth.  Map Data: Google Earth, Landsat/Copernicus This application draws circles for display on digital maps and virtual globes using KML. A circle can be rendered as a LineString, Polygon or MultiGeometry. An optional Point displaying the center can be included as well.

Very large circles can be generated; up to 20,000 Km radius.

Note that KML will not render Polygons enclosing the North or South Poles and instead will wrap around the pole(s). This limitation does not apply to LineStrings but does affect the strategy I use to generate Polygons. If a Polygon encloses a pole, a thin slice is cut to the pole, minimizing the visual impact of the wrapping. If drawing a circle that encloses one or both of the poles, I recommend selecting MultiPolygon, which generates a well formed LineString outlining a Polygon used for the fill.

Inputs

Coming Soon!

  1. Choose the Number of Nodes defining the circle, from 3 to 360. Why? Fewer coordinates make lighter files where resolution is less important. This will also enable drawing regular polygons such as triangles, squares and hexagons - though they will have curved sides, of course.
  2. Choose the Heading of the first coordinate.
    Why? To orient (turn) the circle/polygon as desired.
  3. Option to select All Types of geometries, Linestring, Polygon and MultiGeometry, in one file.
  4. Choose between using Great Circle (?) or Rhumb Lines (?) to render your circles.
    Why? Because I can. ;-)
    Currently, these circles are rendered with Great Circle distances from the center point at each degree. Using Rhumb Lines alters the distortion of the circle in ways that might be better for some applications.

Do you have an idea, suggestion or feature request (or find a bug)? Let me know here. -Scott