Reading A Map Flashcards
Top margin
Series name, scale, sheet name, edition number, series number, sheet number
Map instructions
Placed around the outer edges of the map.
Series name
Usually includes a group of similar Maps at the same scale or the same sheet lines designed to cover a particular geographical area. Name given to a series is that of most prominent areas.
Scale
Indicates relative value of distance on the map compared to distance on the ground. For example a map with a scale of 1:50,000 means that 1 inch on the map equals 50,000 inches on the ground for 1270 m. As ratio increases, map details decreases.
Sheet name
Bold print at the center of the top and in the lower left area of the left margin. A map is generally name for the settlement contained within the area covered by the sheet, or for the largest natural feature located within the area at the time of the map was drawn.
Edition number
Age of the map in relation to other additions of the same map and the agency responsible for its production
Series number
A sequence reference Expressed either as a four digit number or a letter followed by a three or four digit number. Found in both the upper right margin and the lower left margin
Sheet number
Used as a reference number for that map sheet. Found in the upper right margin and the lower left margin
Lower right margin
Includes the declination diagram, elevation, boundaries, adjoining sheets
Declination diagram
Difference between true North, great north, and magnetic north. Value shown in degrees. Used when converting magnetic azimuth shown in your lensatic a compass it out to a grid azimuth on your map. Also used to convert a grid azimuth to a magnetic asthma
Elevation guide
Miniature characterization of a terrain shown. Terrain shown by bands of elevation (contours), spot elevations, and major drainage features. On most Maps the higher elevations are represented by darker color.
Boundaries
Shows boundaries that occur within the map area such as county lines and state boundaries
Adjoining sheets
Shows how the map connects to other Maps.
Bottom margin
Includes contour interval note, legend, bar scales
Contour interval note
States the vertical distance between adjacent contour lines on the map. When supplementary contours are used, interval is indicated.
Legend
Illustrates and identifies the topographic symbols used to depict some of the more prominent features on the map, such as railroad tracks, buildings, and swamps.
Bar scales
Used to convert map distance to ground distance. May have three or more bar scales per map. In center of the lower margin.
Map colors
Standard colors on a military map include black, red/brown, blue, green, brown, red
Black
Depicts cultural (man-made) features such as buildings, transportation features, surveyed spot elevations, and all labels
Red/brown
Identifies cultural features, all relief features, non-surveyed spot elevations, and elevation (such as contour lines on red-light readable Maps).
Blue
Water features such as lakes, swamps, wetlands, rivers, and streams.
Green
Vegetation with military significant such as Woods, orchards, and Vineyards.
Brown
Really features and elevation such as contours on older edition maps and cultivated land on red-light readable Maps
Red
Cultural features such as populated areas, main roads, and boundaries (on older Maps)
Elevation (contour lines)
Contour lines are the most common method of showing relief in elevation on a standard topographical map. Represents imaginary line on the ground above or below sea level. All points on the contour line are at the same elevation. The elevation represented by contour lines is the vertical distance above or below sea level. There are three types of contour lines used on a standard topographic map
Index lines
Starting at zero elevation or mean sea level, every fifth contour line is a heavier line. These are known as index contour lines. Normally each index contour line is numbered at some point. This number is the elevation of that line
Intermediate lines
Fall between the index contour lines. These lines are finer and do not have their elevations given. There are normally four intermediate contour lines between index contour lines
Supplemental line
Resemble dashes. They show changes in elevation of at least one half the contour interval. These lines are normally found where there is very little change in elevation such as on fairly level terrain
Terrain features
Heels, riches, saddles. In defense of operations, the higher ground is preferred.
Hill
Area of high ground. Shown on map by contour lines forming concentric circles
Ridge
A ridge is a sloping line of high ground. Contour lines forming a rich tend to be U-shaped or V-shaped. The closed in of the contour line points away from High ground
Saddle
A saddle is a dip or low point between two areas of high ground. On a map A saddle is normally represented by an hourglass
Ambush terrain features
Spur, draw, Valley
Draw
A drawl is a less developed stream course then a valley. In a draw, there is essentially no level ground and, therefore, little or no maneuver room within its confines. The contour lines depicting a draw are U shaped or a V shape, pointing toward high ground
Valley
A Valley is a stretched out groove in the land, usually formed by streams or rivers
Spur
A spur is a short, continuous sloping line of higher ground, normally jutting out from the side of the ridge. A spur is often formed by two roughly parallel streams cutting draws down the side of the ridge. The ground will slow down in three directions and up one
Terrain features that probably need to be avoided
Cut, depression, Cliff
Cut
Man-made feature resulting from cutting through raised the ground, usually to form a little bit for a road or railroad track
Depression
A depression is a low point in the ground or a sinkhole. It could be described as an area of low ground surrounded by higher ground in all directions, or simply a hole in the ground
Cliff
A Cliff is a vertical or near vertical feature. It is an abrupt change of the land, when a slope is so steep that the contour lines make converge into one
Water features on a topographic map are shown in blue
Wetlands, streams, lakes, oceans
Basic map reading rule
Always read right then up. Always read right on the vertical gridlines then up on the horizontal gridlines
Grid and squares
Coordinates always point to the lower left corner of the squares
Four digit grid coordinates
Within 1000 m of the objective
Six digit grid coordinates
Within 100 m of the objective
Military protractor
Military Maps do not have 100 m squares. Protractors help us determine six digit coordinates. The correct angle will have a horizontal and vertical axis that matches the grid squares on your map.
Eight digit grid coordinates
Reads within 10 m of objective
