NFST Map and Route Analysis 4 — Questions and Answers
Question 1: A UTM (Universal Transverse Mercator) grid coordinate is useful in the field primarily because it:
- Uses the same degree-minute-second system as GPS receivers only
- Provides a simple metric grid making distance calculations straightforward (Correct answer)
- Is based on the magnetic north pole for accurate compass use
- Requires no conversion when used with topographic maps
Correct answer: Provides a simple metric grid making distance calculations straightforward
UTM uses a metric grid system that makes measuring distances simple — every 1,000 meters is a 1 km grid square.
Question 2: When orienting a topographic map to the terrain using a compass, you should:
- Rotate the map until the compass needle points to the top of the map
- Rotate the map until the north arrow on the map aligns with magnetic north, accounting for declination (Correct answer)
- Point the direction-of-travel arrow toward your destination and rotate the map to match
- Always hold the map facing south for accurate field use
Correct answer: Rotate the map until the north arrow on the map aligns with magnetic north, accounting for declination
Orienting the map means aligning its north arrow with true north (accounting for magnetic declination) so map features match the terrain around you.
Question 3: A 'relief map' or shaded relief map uses shadows and highlights to show:
- Road surface quality and condition
- Three-dimensional terrain shape and elevation changes (Correct answer)
- Vegetation type and forest cover density
- Political boundaries and land ownership
Correct answer: Three-dimensional terrain shape and elevation changes
Shaded relief maps simulate sunlight on terrain to create a 3D visual effect, making hills, valleys, and ridges intuitively obvious.
Question 4: In forest service navigation, 'terrain association' refers to:
- Using only GPS devices for all navigation decisions
- Identifying your location by matching surrounding terrain features to map features (Correct answer)
- Memorizing all place names in an area before entering it
- Associating each trail junction with a specific compass bearing
Correct answer: Identifying your location by matching surrounding terrain features to map features
Terrain association is the skill of comparing visible landscape features (ridges, drainages, peaks) directly to map symbols to determine your location.
Question 5: Which of the following conditions would most likely cause a GPS receiver to give inaccurate position readings in a forested or canyon environment?
- Using the device in temperatures below 50°F
- Poor satellite geometry or signal blockage by terrain and tree canopy (Correct answer)
- Operating the GPS with a partially charged battery
- Failing to enter the correct map datum before use
Correct answer: Poor satellite geometry or signal blockage by terrain and tree canopy
Dense tree canopy and surrounding terrain can block or reflect GPS satellite signals, degrading position accuracy.
Question 6: On a fire behavior map used during wildland fire operations, an area marked as 'anchor point' typically indicates:
- A location where aircraft should drop retardant
- A safe starting point from which fire lines can be built without being flanked by fire (Correct answer)
- The predicted point of fire origin
- A mandatory crew rest area during operations
Correct answer: A safe starting point from which fire lines can be built without being flanked by fire
An anchor point is a secure location (natural barrier, burned area, road) from which crews begin constructing fire line safely.
Question 7: When planning a route on a map, 'line of sight' analysis determines whether:
- A route follows a straight line between waypoints regardless of terrain
- Two points are visible to each other with no terrain obstruction between them (Correct answer)
- A communication radio signal will reach all team members
- A route stays within a specific elevation band
Correct answer: Two points are visible to each other with no terrain obstruction between them
Line of sight analysis uses elevation profiles to determine if terrain obstructs the direct view between two geographic points.
NFST Map and Route Analysis 4
A UTM (Universal Transverse Mercator) grid coordinate is useful in the field primarily because it: