The face panel includes a 3-digit speed display and
three buttons: menu, select, and power. Using the "menu" and "select"
buttons you can control display backlighting, cosine correction,
serial communication output mode, and high / low speed range settings.
There are times when you have to point the radar
gun at an angle to read your target. This angle introduces what is
known as a cosine error. You can eliminate (or greatly reduce) this
error by setting the angle correction software for a particular angle
and then aiming the radar gun at that angle.