Add a true north arrow to your ArcMap page layout

Adding a north arrow improves many maps, especially large scale maps that show a smaller area with lots of detail and maps that are not oriented with north up (Figure 1), which is often done to save space on the printed page.

Figure 1. In this example, adding a north arrow benefits a map that is not oriented with north at the top of the page.

A new ArcMap option in ArcGIS 10.1 lets you add a north arrow aligned with true north to your layout. True north is the direction pointing to the geographic north pole of the earth’s axis of rotation, the location at 90 degrees north where all meridians converge. (Meridians are the north-south lines on the earth that extend between the north and south poles.)

In previous versions of ArcGIS, a north arrow inserted into a layout in ArcMap was always grid-aligned to the north of the data frame. (Read the blog Adding a declination diagram in ArcMap.) The north arrow always points to the top of the page, unless you rotate the data frame. In ArcGIS 10.1, you can now choose to align the north arrow to the direction of true north at the center of the data frame.

To illustrate this, Figure 2 below shows the orientation of the north arrow when placed on maps using the Albers equivalent projection of North America with standard parallels at 20N and 60N and the central meridian at 96W (shown in orange in Figure 2B). When the true north alignment option is used, the north arrow aligns to the meridian in the center of the data frame that points to true north. Note that if you move the north arrow to another location on the page after inserting it, its orientation will remain the same. If you move the data in the data frame, the north arrow will update automatically.

Figure 2. These maps show a north arrow using the true north alignment option.
Figure 2. These maps show a north arrow using the true north alignment option.

Note that the maps in Figure 2 are for illustrative purposes only. Cartographers advise against using a north arrow on smaller scale maps that use conical projections such as these, because north varies on the map, as you can clearly see by the orientation of the meridians.

To set the true north alignment option, follow these three simple steps:

The first step: Click on Insert in the main menu, then on North Arrow.

Second step : Use the north arrow selector to choose the north arrow you want to insert, then click Properties.

Third step: On the North Arrow tab, set the Align To option to True North (Figure 3) and click OK.

Figure 3. Set the Align option to True North in the North Arrow Properties dialog box.
Figure 3. Set the Align option to True North in the North Arrow Properties dialog box.

Note in Figure 3 that the calculated angle automatically updates to indicate the angle of the true north arrow. The calculated angle is always a read-only property, calculated by the software.

You can also set a calibration angle to set adjustments for data frame rotation or true north alignment options. For example, you can use this option with alignment to true north if you insert a north arrow that aligns to magnetic north. Magnetic north is the direction of a compass needle when aligned with the earth’s magnetic field. To set this value, you will need to know the correct declination (the angular difference between true north and magnetic north) for the time and area being mapped.

Here are some other guidelines for using the true north alignment option:

  • You can use the Style Manager to change the alignment setting of a north arrow symbol so that the symbol defaults to the rotation option you set.
  • The calibrated angle can be changed by the user with either rotation option. The calculated angle is determined by the software, so it’s not something you can change.

To learn more about north arrows in ArcMap, read these ArcGIS blog posts:

About the Author

Aileen Buckley

Aileen Buckley is a mapping researcher on the ArcGIS Living Atlas of the World team and a member of Esri’s Virtual Science Team. She holds a doctorate in geography from Oregon State University.