Range Rings for Google Earth (RINGS)
This page describes a free application that runs in
Google Earth version 5.0 or later. Please install
Google Earth,
download
RINGS,
and return to this page to learn more.
RINGS is an online tool that draws concentric circles in Google Earth. Radii
may be specified from 10 to 1,000,000 for units of US survey feet or meters
and from 0.25 to 10,000 for units of miles (1 mi = 5280 survey ft) or kilometers.
Line color is selected from a 24-color palette, and line width may be specified
from 0.1 to 10.
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Position the point of interest (POI) in the center of the view. One way to
do this is to double-click an unmarked location. To precisely position the
POI in the center of the view, add a placemark at the desired location;
then edit the properties of that placemark and reset the view.
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Check the box beside the Setup network link.
A form will be presented with read-only coordinates corresponding to
the view center and input fields for ring parameters. Range rings are
drawn when the Draw button is pressed.
-
On subsequent uses, reposition the POI and ensure that the network link
is checked and selected. Then choose Refresh from the Edit menu,
or right-click and select Refresh in the context menu.
© 2010 Google - Image USGS
All radii are integral multiples of the user-specified Normal
Radius Interval. The minimum radius interval is 10 for feet or meters
and 0.25 for miles or kilometers. A maximum of 200 rings may be drawn per query.
To suppress index rings, set the Index Radius Interval
to any value greater than the Ending Radius, or set the normal
and index line colors and widths to the same respective values.
Range rings are rendered as regular polygons with 72 vertices on the WGS84
ellipsoid using Vincenty's
nested
equations. The computed vertices typically exhibit submillimeter agreement
with the NGS online
Inverse/Forward computation utilities. The Google Earth measuring tool is
grossly less accurate.
Note: To save range rings from one Google Earth session to another, right-click
on Saved Regions and select Copy; then right-click on My Places and
select Paste.
RINGS is a component of Earth Survey
© 2007-2010
Metzger & Willard, Inc.
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