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north arrow with UPS projection

December 15 2009 | 0 comments
Categories: Map Elements

What is common practice for map orientation and the use of north arrows for maps using the UPS projection? Do you keep grid north up and turn the north arrow accordingly, or do you rotate the map so true north is up and so the UPS grid is tilted like with the UTM projection? With UPS the rotation could be very large, up to 180 degrees.

Mapping Center Answer:

There can be a variation between true and grid north of up to 180 deg. for the UPS system. Take a look in the attached document on page 3-3. You can see that the line that follows the meridian from the pole to 180 degrees at the top of the map is actually exactly opposite (true north is towards the bottom and grid north is towards the top). You can also see on that diagram that one way to indicate this is to include an arrow that is labeled "Grid North" as map marginalia.

Although we haven't seen a large scale topo map of these areas, it seems that either aligning the map to true north or grid north is done for specific applications. A declination diagram should show the difference between the two in either case, but the map user should be aware that there will be a significant variation in the orientation of meridians across the map for all but large scale maps.

Thanks for a head scratching question! It took a few of us cartographers to figure this out collectively!

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