Where is the Horizontal Reference Point on the display?

Where is the Horizontal Reference Point on the display?

The Horizontal Reference Point is displayed as a red triangle at the top of the graticule area. In its default position, it is located in the upper left hand corner of the graticule area.

To move the Horizontal Reference Point, use the mouse to drag it across the top of the graticule to the desired location. Observe that the horizontal position value changes as the Horizontal Reference Point is moved.