Map Basics
A geographic representation of a portion of the earth's surface, drawn to scale, as seen from above.
What is a map?
The number of MAJOR terrain features.
What is five? (Hilltop, Valley, Ridge, Saddle, Depression)
When reading a grid coordinate, you always go this direction first — then up.
What is right? (Right, then up)
The most common military method used to express direction.
What is an azimuth?
The compass hold that is faster and easier, but less precise.
What is the center hold method?
This map color represents drainage — lakes, rivers, and other water features.
What is blue?
A dip or low point between two areas of higher ground — its contour lines usually look like an hourglass.
What is a saddle?
A four-digit grid coordinate locates a point within this distance.
What is 1,000 meters?
To find the back azimuth of an azimuth that is LESS than 180 degrees, you do this.
What is add 180 degrees?
The compass technique used almost exclusively for sighting — the most precise method.
What is the compass-to-cheek technique?
250,000 map is considered this size scale.
What is small scale?
A low point or sinkhole, shown by closed contour lines with tick marks pointing toward low ground.
What is a depression?
A six-digit grid coordinate locates a point within this distance.
What is 100 meters?
The back azimuth of 287 degrees.
What is 107 degrees?
Metal can affect your compass azimuth from up to this distance away.
What is 1 meter?
On red-light readable maps, this color shows relief features and contour lines.
What is red-brown?
A short, continuous sloping line of higher ground jutting out from the side of a ridge — its U or V contour lines point AWAY from high ground.
What is a spur?
An eight-digit grid coordinate locates a point within this distance.
What is 10 meters?
The three types of north.
What are true north, magnetic north, and grid north?
The three units of measure typically found on a map's graphic bar scale.
What are statute miles, kilometers, and nautical miles?
A map is in this state when it is horizontal and its north/south corresponds to north/south on the ground.
What is oriented?
The two SUPPLEMENTARY (man-made) terrain features, usually built to make a level bed for a road or railroad.
What are a cut and a fill?
The GTA 5-2-12 — the most commonly used version of this tool for plotting coordinates and measuring grid azimuths.
What is the military protractor (coordinate scale)?
The angular difference between two norths — you use its diagram to convert between grid and magnetic azimuths.
What is declination?
Converting a WESTERLY magnetic azimuth to a grid azimuth — do you add or subtract the G-M angle?
What is subtract?