Land Navigation Flashcards
What is mariginal on a map used for?
- Identification — indicates which area coverage the map represents.
- Interpretation — provides correlation between actual terrain features and map topographic symbols.
- Evaluation — helps determine the validity of the information represented on the map.
What are the different colors used to represent different terrain features on a map?
- Black: manmade features.
- Brown: terrain features.*
- Green: vegetation.
- Blue: water.
- Red: road conditions and built-up areas.*
Within how many meters will a 6 grid get you?
100m accuracy
Within how many meters will a 8 grid get you?
10m accuracy
Within how many meters will a 10 grid get you?
1m accuracy
What are the 3 tyoes map scales?
- Large scale: 1:75,000 and larger.
- Medium scale: Smaller than 1:75,000 and larger than 1:600,000.
- Small scale: 1:600,000 and smaller.
What are large maps used for?
- Cover relatively small area.
- Contain good detail.
- Are used for tactical purposes.
What are medium maps used for?
- Cover a larger area.
- Contain less detail.
- Are used for strategic purposes and aerial navigation.
What are small maps used for?
- Cover an extremely large area.
* Contain almost no detail.
Define true north
Point on earth where lines of longitude converge (i.e., North Pole).
What is magnetic north?
Lensatic compass always points to magnetic north. Lines not shown on map. Used to navigate in the field.
What is grid nroth?
Parallel lines on the map which do not converge at North Pole. Based on Military Grid Reference System (MGRS).
Define Declination
The angular difference between true north and grid north or magnetic north. Declination is ALWAYS measured from true north.
Define azimuth
A horizontal angle measured clockwise from a base line.
What is a back azimuth?
A back azimuth is the reverse (plus or minus 180) of an azimuth, either magnetic or grid. If the original azimuth is
Less than 180, add 180
More than 180, subtract 180
What are the 3 methods to convert from grid to magnetic azimuths?
LARS, MAGMGA, Picture method
What are the 3 methods of locating positions
inspection, intersection, and resection.
What are the 2 ways to locate positions using the intersection method?
one point and two point intersection
Define terrain profile
exaggerated side view of a portion of the earth’s surface along a line between two points.
What military applications does terrain profiling include?
- Determining the most effective fields of fire for direct fire weapons.
- Determining dead space to be covered by indirect fire weapons.
- Determining visibility and hidden areas from observation posts.
- Various applications for engineers, communicators, and aircrews.
Define the intersection method
The location of an unknown point by sighting on the unknown point from one or more known positions.
Define the resection method
A method of determining your location by sighting on one or more known terrain features.
What are some water features such as lakes or streams be categorized as?
- Perennial: they contain water more than six months of the year.
- Intermittent: they contain water less than six months of the year.
Which vegetation feature is not shown on a map?
Annual vegetation
What are the 5 types of vegetation shown on a map?
Woodlands, Scattered trees, Scrub, Orchards, Vineyards
What are some types of manmade features?
Roads, railroads, bridges, power transmisson lines, airfields, buildings
How are roads shown on a map
With a variety of reddish brown or black lines
How are airfields shown on a map?
Airfields with a dirt or grass surface are shown with dashed black lines; paved surfaces are shown with solid black lines.
What acronym do we use when describing landforms?
Shape, Orientation, Size, Elevation, Slope (SOSES)
What are the types of contour lines?
Index, Intermediate, supplementary, depression, cliff
What are the types of slopes?
Uniform steep, Uniform gentle, Concave, Convex
What are the 2 basic techniques for using the lensatic compass?
Center hold technique and compass-to-cheek technique
What is an attack point?
An easily recognizable feature positively identified on the map and on the ground, preferably 400 meters or less from your objective.
Define collecting features
Features that you plan to cross enroute to your objective.
Define limiting/catching feature
Predetermined feature, preferably linear (such as a stream, finger, or road), beyond your objective. If you reach this feature when navigating, you will know that you have traveled past your objective without finding it.
Define Terrain association
The process of using terrain features to guide the navigator to the objective with little or no reliance on the compass.
What is 90 degree offset?
technique is used when you are not able to cross a sizable obstacle.
