Map Reading and Land Navigation Flashcards
what’s a map?
a graphic representation of the Earth’s surface, drawn to scale as seen from above
what document covers map reading and land navigation?
TC 3-25.26
what’s the purpose of a map?
to provide accurate information about the existence, location and distance between ground features like terrain, elevation, populated areas, routes of travel and communication
what is the scale of a map?
the ratio of ground distance to map distance and expressed in a fraction
how many map scales are there and what are the names?
there are 3 map scales, planimetric map, photomap, terrain model
what is marginal information?
instructions about the maps use, size, area
where is the map sheet name found?
two places: the center of the upper margin and either the right or left of the lower margin
what is a topographic map?
a map that portrays the layout of terrain features, as well as relief, or the vertical distance of the feature . (distance from sea level)
what is a photomap?
an aerial photomap of a portion of the Earth’s surface on which grid lines, place names and approximate scale and direction have been added.
what is a planimetric map?
a map that only shows the horizontal positions of features. it differs from a topographic map in that it omits relief, usually represented by contour lines.
what is a map usually named after?
The most prominent geographical or cultural feature. Whenever possible it is named after the largest city on the map
where is the declination diagram found?
It’s located in the lower margin of large-scale maps
where is a map sheet number found?
In two places: the upper right and lower left margins
Where is the map series name found?
It’s found in the upper left margin
What is a declination diagram?
It shows the angular relationships of true north, grid north, and magnetic north
where is the series number found?
the upper right and lower left margins
Where is the scale of the map found?
In the upper left margin after the series name and in the lower margin at the center
Where is the edition number of a map found?
The upper margin and in the lower left margin, It represents the age of the map- the higher the number the more recent the edition of the map. the initials, or the abbreviation after the edition number indicates who made the map
Where are the bar scales of a map located?
In the center of the lower margin
What is a bar scale?
A ruler used to convert map distance to ground distance
What are the usual three units of measure in a bar scale?
They are eters, statute miles, nautical miles
Where is the contour interval note found?
Usually below the bar scales in the middle of the lower margin
Where is the legend of a map found?
in the lower left margin
What is a contour interval?
The vertical distance of the space between the contour lines. In more recent maps that distance or space is given in meters instead of feet
What is in a map legend?
the symbols that represent topographic features. the symbols are not always the same
how many colors does a map usually have?
five
What are the colors on a map?
black, blue, green , brown, red (reddish brown if the map is readable by red light)
What does the color black represent on a map?
man-made features like buildings and roads
what does the color blue represent on a map?
water features, like lakes, swamps, rivers and drainage
what does the color green represent on a map?
vegetation with military significance such as woods, orchards, or vineyards
what does the color brown represent on a map?
all relief features and elevation, as well as contour lines on older maps
what is longitude?
a measure of distance east or west of the prime meridian
in what city is the prime meridian?
Greenwhich, England