Azimuth Defined
Definition of “Azimuth”: Azimuth is a quantitative measure of direction. Azimuth is a common term used in astronomy, navigation, surveying and gunnery as a means of measuring direction quantitatively.
What does “Azimuth Check” mean?
The military commonly uses the term “azimuth check” or “ check your azimuth” to mean literally to check or verify your direction of travel while navigating. To do so, requires that you take out your compass and verify that your current direction of travel (or “azimuth”) is aligned with the correct heading needed to reach the intended destination. If not, then make the necessary adjustments to get back on the correct azimuth.
“Azimuth check” also means to verify that weapons are pointed in the right direction, especially for those weapons that require precise calculations and an accurate direction of fire in order to hit distant targets. Typically for such weapons like howitzers (essentially modern cannons used by those in the field artillery), multiple attempts with successive adjustments are required to literally “hit the target”.
The term “azimuth check” also has a figurative meaning: to check or reassess your goals, values and methods. It often requires making multiple adjustments along the way, while progressing toward reaching your ultimate target or achieving your objectives.
For more detailed definitions, explanations and usages of the term “azimuth”, click here.
1: an arc of the horizon measured between a fixed point (as true north) and the vertical circle passing through the center of an object usually in astronomy and navigation clockwise from the north point through 360 degrees.
2: horizontal direction expressed as the angular distance between the direction of a fixed point (as the observer’s heading) and the direction of the object.
The military defines an azimuth as a horizontal angle measured clockwise from a north base line. Azimuth is the most common military method to express direction. When using an azimuth, the point from which the azimuth originates is the center of an imaginary circle (Figure 1). This circle is divided into 360 degrees or 6,400 mils.
This north base line may be one of three different norths: True north, Magnetic north, or Grid north, the latter two being most commonly used.
1.) True North. A line from any point on the earth’s surface to the north pole. All lines of longitude are true north lines. True north is usually represented by a star (Figure 2).
2.) Magnetic North. The direction to the north magnetic pole, as indicated by the north-seeking needle of a magnetic instrument. The magnetic north is usually symbolized by a line ending with half of an arrowhead (Figure 2). Magnetic readings are obtained with magnetic instruments, such as lensatic and M2 compasses.
3.) Grid North. The north that is established by using the vertical grid lines on the map. Grid north may be symbolized by the letters GN or the letter “y” (Figure 2).
Reference: U.S. Army Map Reading and Land Navigation Handbook. Field Manual 3-25.26.