114 LAND NAVIGATION FUNDAMENTALS Flashcards
What is the sheet name of a map based on?
The most prominent cultural or geographical feature, often the largest city.
Where is the sheet name located on a map?
Center of the upper margin and either the right or left side of the lower margin.
What is the purpose of the sheet number on a map?
It serves as a reference number for that map sheet.
Where can you find the sheet number on a map?
Upper right margin and lower left margin.
What does the scale of a map represent?
The ratio of a distance on the map to the corresponding distance on the earth’s surface.
How does a 1:25,000 scale differ from a 1:50,000 scale?
A 1:25,000 scale shows more detail because 1 inch represents 25,000 inches on the ground, versus 50,000 inches for 1:50,000.
Where is the scale located on a map?
Upper left margin after the series name and center of the lower margin.
What does the elevation guide illustrate?
A miniature characterization of terrain with bands of elevation, spot elevations, and major drainage features.
Where is the elevation guide typically found?
Lower right margin.
What does the declination diagram show?
The angular relationships of true north, grid north, and magnetic north.
What additional information is included with the declination diagram?
A note on converting azimuths from grid to magnetic and magnetic to grid.
Where is the declination diagram located?
Lower margin.
What are bar scales used for on a map?
Converting map distance to ground distance, with multiple scales in different units.
Where are bar scales positioned on a map?
Center of the lower margin.
What does the legend identify on a map?
Topographic symbols for prominent features like railroad tracks, buildings, and swamps.
Where is the legend found on a map?
Lower left margin.
Why should you always check the legend when reading a map?
Symbols vary between maps, and checking avoids errors.
What are grid lines on a map?
Straight lines intersecting at right angles, forming a system of squares like city streets.
What are principal digits in grid lines?
Two-digit numbers printed at grid line ends and intervals, used for referencing points.
What size are most grid squares on a military map?
1000 meters by 1000 meters.
What is the basic map reading rule for designating a point?
Read right then up, using vertical then horizontal grid lines.
Why is grid square identification important in map reading?
It allows accurate location of points within a grid square using the read right then up rule.
How precise is a four-digit grid coordinate?
Locates a point within 1000 square meters (a grid square).
What accuracy does a six-digit grid coordinate provide?
Locates a point within 100 meters on a map.