Land Nav Flashcards
(110 cards)
1
Q
What do contour lines on a topographic map represent?
A
Elevation changes—closer lines mean steeper terrain.
2
Q
What is map scale 1:24,000 commonly used for?
A
Detailed field navigation—1 inch = 2,000 feet on the ground.
3
Q
What is declination in land navigation?
A
The difference between true north and magnetic north.
4
Q
What is Arizona’s approximate magnetic declination?
A
+10 to +12° east.
5
Q
How do you orient a map with a compass?
A
Set declination, lay the map flat, rotate both map and compass until north lines align.
6
Q
What are the steps to take a field bearing with a compass?
A
Point arrow at target
Rotate housing to align needle
Read bearing at index line
7
Q
What does ‘red in the shed’ mean in compass use?
A
Aligning the magnetic needle inside the orienting arrow to take a bearing.
8
Q
How do you plot a bearing on a map?
A
Mark your location, find destination, draw line, read angle, adjust for declination.
9
Q
What is a saddle on a topographic map?
A
A low area between two higher elevations, like a dip or pass between peaks.
10
Q
How is a ridge represented on a topo map?
A
Contour lines forming a “U” or “V” that point away from high ground.
11
Q
What is a spur or draw?
A
A spur is a short, sloping ridge—draws are small valleys running downhill.
12
Q
What do depressions look like on a topo map?
A
Contour lines with tick marks (hachures) pointing inward—indicating a hole or sink.
13
Q
What is the contour interval, and why is it important?
A
The vertical distance between contour lines—tells you the steepness of terrain.
14
Q
How do you identify a cliff on a topo map?
A
Contour lines stacked tightly together—sometimes nearly overlapping.
15
Q
What is a reentrant?
A
A small, narrow valley often used as a route uphill—lines form a “V” pointing up.
16
Q
What is a knoll or hilltop?
A
Closed contour circles with elevation increasing toward the center.
17
Q
What is “back azimuth”?
A
The opposite direction of a bearing—add or subtract 180° to reverse a heading.
18
Q
How do you correct a magnetic bearing for true north?
A
Add or subtract your local declination (east declination = subtract).
19
Q
What is “magnetic deviation”?
A
Error in compass reading caused by nearby metal objects or electronics.
20
Q
When should you use a compass bezel (rotating dial)?
A
To take bearings, plot courses, and maintain orientation while walking.
21
Q
How do you follow a bearing in the field?
A
Align compass, sight a distant landmark, walk toward it, then repeat.
22
Q
What’s the best way to keep your bearing while hiking rugged terrain?
A
Use “leapfrogging” with identifiable landmarks to stay on course.
23
Q
What does a baseplate compass’s orienting lines help with?
A
Aligning the compass with map grid lines for accurate bearings.
24
Q
Why is a compass with a sighting mirror useful?
A
It allows more accurate bearings and can double as a signaling tool.
25
What is 'terrain association'?
Using land features to confirm your position and direction while navigating.
26
What is 'handrailing' in land nav?
Following a linear feature (like a ridge, road, or creek) to guide your movement.
27
What is a 'catch feature'?
A large, unmistakable feature that tells you if you’ve gone too far.
28
What is 'aiming off'?
Intentionally aiming to one side of a target feature to ensure you find it from a predictable direction.
29
What is 'baseline orientation'?
Maintaining awareness of general direction (e.g., always knowing which way is north).
30
How can you use shadows to find direction without a compass?
Use the shadow stick method—track shadow movement to find east-west line.
31
What’s a good habit for confirming your position often?
Triangulate using at least two visible landmarks and your map.
32
What is a 'pace count' used for?
Estimating distance traveled by counting steps—used in dead reckoning.
33
What does UTM stand for?
Universal Transverse Mercator—a coordinate system that divides the Earth into zones using meters.
34
How is the UTM grid structured?
Eastings (horizontal) and northings (vertical), measured in meters from zone origins.
35
What’s a practical advantage of using UTM over latitude/longitude?
It allows for easier distance calculation and map reading in the field.
36
How accurate is a full 8-digit UTM coordinate?
Within 10 meters of the target point.
37
How do you read UTM coordinates on a map?
Easting first (left to right), then northing (bottom to top).
38
What tool is typically used to plot UTM coordinates?
A grid reader or coordinate scale ruler.
39
What’s the difference between a 4-digit, 6-digit, and 8-digit UTM?
4-digit: 1,000m accuracy; 6-digit: 100m; 8-digit: 10m.
40
How do you find your UTM zone?
Check the zone label on your map or use your GPS—most of Arizona is Zone 12S.
41
What is dead reckoning in land navigation?
Estimating your current position based on last known location, bearing, and pace count.
42
What is terrain association?
Using visible features like ridges, valleys, and streams to confirm or adjust your position on a map.
43
What is handrailing?
Navigating by staying close to a linear feature (like a trail, stream, or ridge line).
44
What’s a catch feature (or backstop) in navigation?
A landmark that signals you’ve gone too far—used to prevent overshooting a target.
45
How does vegetation affect compass accuracy?
Dense brush or iron-rich rock can distort magnetic readings—cross-check bearings.
46
What is resection in land nav?
Determining your location by taking bearings to two or more known landmarks and drawing lines back to where they intersect.
47
What’s a common cause of GPS error in canyons or forests?
Satellite signal blockage or reflection—known as multipath error.
48
What should you do if your compass needle fluctuates near your body or gear?
Move away from metal or electronics—ensure compass is free from interference.
49
Why is nighttime navigation more hazardous?
Reduced visibility, greater disorientation risk, and difficulty recognizing terrain features.
50
What’s the safest practice when you lose your position?
Stop, orient map and compass, look for terrain features, and reorient using known references—don’t panic or blindly continue.
51
What are the three components of a route plan?
Start point, checkpoints (waypoints), and destination.
52
What is a control feature in route planning?
A distinct, identifiable landmark used to confirm location and guide movement.
53
What’s a travel corridor in backcountry navigation?
A zone between two linear terrain features (e.g., ridges or streams) used to funnel movement and minimize drift.
54
What is a dogleg route and why use it?
A deliberate off-angle detour to avoid obstacles or align with easier terrain—used when straight-line travel is impractical.
55
Why avoid ridgeline travel during lightning storms?
Ridges and peaks are lightning attractors—seek lower terrain if thunder is audible.
56
What’s the “aiming off” technique in land nav?
Intentionally aiming to one side of a linear feature so you know which direction to turn when you hit it.
57
What’s a pace count, and how do you establish one?
Number of steps taken to cover 100 meters—measured on flat and rough terrain to estimate distance.
58
What’s a reentry control technique?
Returning to a known feature or waypoint to reestablish position when lost or off-route.
59
Why include time estimates in a route card?
To help track pace, anticipate fatigue, and cue alerts if you’re moving too slow or too fast.
60
How does SAR prioritize terrain in a grid search?
Focus on likely survival zones first: near water, shelter, and visible features like trails or high ground.
61
What is the Universal Transverse Mercator (UTM) system?
A grid-based coordinate system that divides the earth into 60 zones, each 6° wide, for precise location referencing.
62
How are UTM coordinates typically written?
Zone number, zone letter, then easting and northing (e.g., 12S 432100 3709800).
63
What tool is used to plot UTM coordinates on a map?
A UTM grid overlay or coordinate scale tool (like a roamer).
64
What is the accuracy of a full 8-digit UTM coordinate?
Within 10 meters of the actual location.
65
How can heavy cloud cover affect land navigation?
Obstructs celestial navigation and aerial references; can reduce visibility and impact terrain recognition.
66
What’s the impact of fog on navigation?
Shortens visible range, disrupts orientation, and demands slower, more deliberate movement.
67
Why is wind direction important in route planning?
Affects scent dispersion, smoke trails, weather patterns, and search strategy in SAR.
68
What tool allows precise bearing readings without moving the compass?
A sighting compass with a mirror or lensatic style.
69
What’s the benefit of using a ranger bead pace counter?
It tracks distance traveled without stopping—ideal for low-visibility or nighttime nav.
70
What is the function of a map protractor?
It allows accurate angle and coordinate measurements for plotting bearings or UTM points.
71
What is the primary challenge of night navigation?
Reduced visibility, making it harder to identify terrain features and maintain orientation.
72
How can you maintain direction at night without visible landmarks?
Use a compass bearing and pace count to track movement; rely on handrails and backstops.
73
What is the 'Silva 1-2-3' method?
A technique for taking and following a bearing: 1) Place the compass on the map, 2) Rotate the bezel to align with north, 3) Follow the bearing in the field.
74
Why is red light preferred for night navigation?
It preserves night vision while allowing map reading and compass use.
75
What is a 'bearing box' in compass navigation?
The area between the orienting arrow and the magnetic needle; keeping 'red in the shed' ensures you're on the correct bearing.
76
How do you adjust your pace count for night navigation?
Expect a slower pace due to limited visibility; recalibrate your pace count in similar low-light conditions.
77
What is the danger of 'drift' in night navigation?
Unintentional deviation from your intended path due to lack of visual references.
78
How can you prevent drift during night navigation?
Use short, frequent compass checks and identify close-range handrails or backstops.
79
What role does sound play in night navigation?
Sound can help identify nearby features like streams or roads when visibility is low.
80
Why is it important to practice night navigation?
To build confidence and proficiency in low-visibility conditions, ensuring safety and accuracy.
81
What’s the core advantage of using GPS in land navigation?
Provides precise location data in real-time, useful for quick position fixes and tracking.
82
What is WAAS in GPS systems?
Wide Area Augmentation System—improves GPS accuracy in North America to within ~3 meters.
83
How does GPS display coordinates for land nav use?
Commonly in UTM or latitude/longitude formats—make sure your map and GPS match.
84
Why should you still carry a compass and map even with GPS?
GPS units can fail due to battery loss, signal issues, or environmental factors.
85
What is a track log on GPS?
A breadcrumb trail showing where you’ve been—useful for backtracking or verifying routes.
86
How can GPS error increase in mountainous terrain?
Signal bounce and blocked satellites cause location inaccuracy—multipath error.
87
What is “GPS drift”?
Slight movement of a stationary GPS signal due to atmospheric conditions or satellite shifts.
88
How often should you waypoint key features during a hike?
At all major turns, water sources, campsites, and junctions to maintain route clarity.
89
What’s a good battery management practice for GPS devices?
Carry spares, keep warm in cold weather, and turn off or dim screen between use.
90
What is the risk of over-reliance on GPS?
Reduced situational awareness, map-reading skills, and failure to notice terrain cues.
91
What is the international distress signal for land-based emergencies?
Three of anything—whistle blasts, flashes, or signal fires spaced evenly.
92
What color signals distress in wilderness survival?
Bright colors not found in nature—typically orange, red, or reflective surfaces.
93
How can you signal an aircraft during SAR?
Use a signal mirror, create a large ground marker (SOS or HELP), or use bright cloth.
94
What does “P.A.C.E.” stand for in SAR navigation planning?
Primary, Alternate, Contingency, Emergency—layers of planning for comms or nav.
95
What is the role of a PLB (Personal Locator Beacon)?
Sends your GPS location to rescuers via satellite when activated—used only in emergencies.
96
What is the first step after realizing you’re lost?
STOP: Sit, Think, Observe, Plan—don’t panic, reassess your situation calmly.
97
How do you increase visibility to search teams?
Move to open ground, wear bright clothing, make noise, and create movement.
98
What is a hasty search in SAR?
A quick, initial sweep of likely locations—trails, water, shelters—prioritizing time over coverage.
99
Why is it important to leave a route plan with someone?
Enables timely SAR response and narrows the search area based on expected locations.
100
What is the most important survival tool in land nav emergencies?
A calm, trained mind—gear helps, but mindset and knowledge save lives.
101
What is “box” or “square” navigation?
A technique using 90° turns to navigate around obstacles and return to your original line of travel.
102
What’s the difference between true north, magnetic north, and grid north?
True = geographic; Magnetic = compass; Grid = map’s vertical lines—each requires adjustment.
103
How do you convert from grid to magnetic bearing on a military-style map?
Subtract the G-M angle (Grid-Magnetic angle), noted in the declination diagram.
104
What’s a “linear attack point”?
A prominent feature near your target used as a final navigation jump-off before precise bearing.
105
How does high altitude affect navigation tools?
Reduced air pressure doesn’t affect compass but may impact physical pace and GPS accuracy.
106
What terrain features are best for route selection in avalanche country?
Low-angle ridges, sparsely treed paths—avoid chutes, bowls, and convex slopes.
107
What’s a practical reason to use resection even if GPS is working?
Confirms GPS accuracy and strengthens map-to-ground correlation—builds trust in the tools and your senses.
108
What is a declination diagram?
A map graphic showing the angle difference between true, grid, and magnetic north.
109
When is a pace count unreliable?
In deep snow, sand, dense brush, or high fatigue—adjust with terrain or time estimates.
110
What’s a “backstop” and “handrail” combo strategy?
Use a linear feature to guide your route (handrail) and a strong terrain feature to prevent overshooting (backstop).
