9th ROTC (Map reading and land navigation)

MAP

a graphic representation of a portion of the earth's surface drawn to scale, as seen from above.

TOPOGRAPHIC MAP

a two-dimensional map which presents the horizontal (flat) and vertical (relief) positions of features represented. Portrays terrain features in a measurable way.

PLANIMETRIC MAP

this is a map that presents only the horizontal positions for the features represented. It is distinguished from a topographic map by the omission of relief, normally represented by contour lines. Sometimes, it is called a line map.

PHOTO MAP

a map reproduction of photograph or photo mosaic upon which grid lines, marginal data, place names and boundaries may be added.

JOINT OPERATIONS GRAPHIC

maps based on the format of standard 1:250,000 medium-scale military topographic maps that contain additional information needed in joint air-ground operations.

PHOTOMOSAIC

an assembly of aerial photographs to form a composite picture; This is an assembly of aerial photographs that is commonly called a mosaic in topographic usage. Mosaics are useful when time does not permit the compilation of a more accurate map.

PLASTIC RELIEF PHOTOMAP

a photomap printed in plastic and molded into a three dimensional form.

PLASTIC RELIEF MAP

a topographic map printed in plastic and molded into a three-dimensional form.

TERRAIN MODEL

a scale model of the terrain showing features, and in large scale models showing   industrial and cultural shapes.

MILITARY CITY MAPS

a topographic map (usually at 1:12,550 scale, sometimes up to 1:5,000), showing the details of a city.

SPECIAL MAPS

these are maps for special purposes, such as traffic, communications, and assault maps. They are usually in the form of an overprint in the scales smaller than 1:100,000 but larger than 1:1,000,000. A special purpose map is one that has been designed or modified to give information not to create confusion.

TERRAIN MODEL

 a three – dimensional representation of an area, mold plaster, rubber of other materials.  It is distinguished from the other maps in that it shows some cultural and terrain features realistically instead of symbolically.

BAR SCALE

located in the center of the lower margin.  They are rulers used for the determination of ground distance.

LEGEND

located in the lower left margin.  It illustrates and identifies the topographic symbols used in the maps.

SHEET NAME

Found in two places; the center of the upper margin and the right side of the lower margin.  

SHEET NUMBER

 found in the right margin of the map.

SERIES NUMBER

 It is a sequence reference expressed either as a four-digit numeral (1501) or as a letter, followed by a three- or four-digit numeral (S711, S701, etc). 

MAP SCALE

a representative fraction that gives the ratio of a map distance to the corresponding distance on the earth's surface.

DECLINATION DIAGRAM

located in the lower margin and indicates the angular relationships of true north, grid north and magnetic north.

GRIP REFERENCE BOX

located in the lower margin and contains information or identifying the grid zone and 100,000-meter square in which the area presented by the map is located and instructions for giving grid reference on the map.

GRIP NORTH

The north that is established on the grid lines by the map. The grid north may be a GN or the letter y.

TRUE NORTH

 A line from any point on the North Pole. All lines of longitude are true north it is usually represented by a star.

MAGNETIC NORTH

The direction to the north indicated by the north seeking needle of a Magnetic North is usually symbolized by a arrowhead; is 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.  

AZIMUTH

An azimuth is defined as the horizontal angle measured from a north base line. This north base line it could be true north or grid north.