Ask A Cartographer

Placement of Compass Rose with Declination

May 27 2008 | 2 comments
Categories: Map Elements

I have a scanned graphic of a compass rose which I would like to place on a map. I would like to locate the graphic on the map based on the True North Declination. Can someone explain the best method for doing this?

Mapping Center Answer:

You can either make a picture marker symbol using your graphic (next to last section in the help topic) as the picture.  Then just add a graphic marker to your data frame or layout in the location you want your compass rose to be shown.  To set the angle, you'll need to know the estimated value of magnetic declination which varies by location and date/time.  NOAA has a online calculator at:  http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp.  That will give you the angle (given your location) you need to use to rotate that graphic marker symbol.

We also have a tool called the Magnetic Calculator in the PLTS Extension that automates this task.

Data Driven Pages posted by Keith McKinnon on Jun 4 2013 4:48PM
This solution is good for a static map. What about data driven pages, especially for those aligned on line features, like trails?
North arrow posted by Aileen Buckley on Jun 4 2013 5:15PM
Would it be better for you to insert a dynamic north arrow rather than as picture of a north arrow? A dynamic north arrow is something that is handled by data driven pages.

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