map & compass. learn how to acquire information from a map learn how to use and navigate with a...
TRANSCRIPT
MAP
&
COMPASS
Learn how to acquire information from a map Learn how to use and navigate with a compass Learn how to plot a route on a map and apply it to
the field with your compassBecome comfortable relying on your map and
compass skills in the woods.
Objectives
Parts of a mapColoursName IndexEditionScaleGlossaryGrid squareGrid referenceContour linesMean declinationMap Datum
Name
Edition
Where else on your map can you find the edition?
Index for 1:50 000 map of Halifax
# don’t always follow each otherWhich map would you choose?
Index for 1:50 000 maps for large area
Scales
A reference for distances on a map
we use maps with 1:50 000 scale and most commonly a 1:10 000 scale
The chequered squares in front of the 0 are for smaller increments
1:50 000
1:10 000
Glossary
Symbols representing objects on a map
NOTE: maps and their symbols can only be as accurate as the “map makers” can make them. The maps are made with from the data of that specific time period.
When was your map made?North American Datum (NAD)?1983
Glossary: Roads
Glossary: Symbols
Glossary: Waterways and woods
How do you determine where you are?Grid Squares
The lines one your maps make squares called grid squares
They help you find yourself more easilyThey can give you a very precise locationGrid squares are always 1 km by 1km (Canadian
maps)
How to use the Grid SquaresUTM: Universal Transverse Mercator Grid
Maps have horizontal and vertical grid lines (like latitude and longitude)
Full grid numbers are found on the corners of the map (ex: left bottom corner 4929000 northing and 422000 easting)
Applicable grid numbers are found along the grid lines and correspond to the bold number
Grid numbers
Reading the grid square1st Eastings: lines that describe your position
eastward/westward, lines that are vertical
2nd Northings: lines that describe your position north/southward, lines that are horizontal
To determine your grid square – start at the bottom left corner of the grid square and read ‘into’ it
OR get into the elevator then go upOR jump over the line, then climb into the square
Grid Square
34_ 71_
65
66
67
68
69
Using a romer 45 46 47 48 49 50
A
B
A = 47_ 68_ B= 48_ 66_
19 7 5 3
97
35
1
4 6 3 3
19 7 5 3
97
35
1
MAP EXERCISE
Describe what you find at the following grid references
1. 427 347
2. 358 474
3. 473 408
4. 367 308
5. 367 394
6. 537 521
Hatchet Lake
Campground
Building
Cochrans Island
Dan Hill
Water Tower
CONTOUR LINESContour lines connect a series of areas of EQUAL ELEVATION
and are used to illustrate relief and dept on a map
Contour line exercise
Contour lines can determine the direction of water flow
Along waterways, contour lines form a ‘V’ shape
The ‘V’ points toward the origin of the river, and therefore,
The river flows away from its origin
Contour lines used to indicate direction of water flow
Water flow exerciseGo to 385 356 to McGrath Falls. There are two
rivers north of it. Which direction is the river flowing from?
410 308 Croucher Lake. There is a river south east of the lake. Which direction is the river flowing from?
Why does the direction of river flow important?
COMPASS360° dial with North sign Direction of travel arrow Index lineOrienteering linesMagnetic needle Base plateRulerScales
Your compass
Your compass
2 Ways to use your compass1. Use it in the field
To get a bearing of the direction you are travelling To orient yourself to a bearing you already have
Use the RED (action) arrow when you’re out being active!
Red in the Bed!
2. Use it to get your direction on a map◦ Use the orienteering lines within the dial to line up with
the lines on the map
Bearing = a number in degrees that depicts a direction (from a map or from a compass)
1. Taking a compass bearing in the field
Hold your compass, cradled flat in your palm, in front and away from your body
Ensure the direction of travel arrow (arrow on the base plate) is pointed at your target
Turn the 360° dial until the Red Needle sits in the
Red Bed (NOTE: this is North, but its not necessarily your bearing!)
Read your ‘magnetic’ bearing at the “index line” on the dial (it may be the same as your direction of travel arrow)
Lets stand up and try it!
Back Bearing
Put the RED in the opposite bed. You get the complete opposite bearing, and it should correlate with where you were just coming from.
Outside effects on a compassAnything magneticPower linesCell phonesGPS
Large amounts of metal Large metal objectsLarge metal veins in rocks
Map and Compass together!
1. Getting a bearing from a map
◦ Determine point A and B◦ Draw a line◦ Set the edge of your compass on the line
**with your direction of travel arrow actually pointing towards your direction of travel !!
◦ Turn the dial – **with the North on the dial pointing North (top of map) – and line up the orienting lines with the gridlines on the map
◦ Read the bearing number at the index line (lines up with direction of travel arrow)
◦ This is a MAP bearing
ORIENTING MAP & COMPASS
A
B
N
Other ways to get a MAP bearing Instead of using your compass to get
the bearing, you can use a protractor. You can also use a transparent square
grid. Using a ruler to calculate distance is
very easy. 360°/0° 270° 90° 180°
Quick bearing taking
N
W E
S
N
W E
S
360°/0° 315° 45°
270° 90°
225° 135° 180°
MAP BEARING EXERCISE
S
1
2
3
4
F
1 2 = ______
S 1 = ______
2 3 = ______
3 4 = ______
4 F = ______
160
060
226
180
080
True North vs Magnetic NorthThere is a Rotational North/South Pole, and a
Magnetic North/South PoleThe magnetic pole is located on Prince of Wales
Island in northern Canada (about latitude 73° N, longitude 100° W)
The angle between the True North or Grid North and the Magnetic North is called the MEAN DECLINATION
Notice that the declination can be towards the east or towards the west, and there is no declination close to western Ontario (Thunder Bay).
The study of the planets magnetic fields is called Geomagnetism.
Mean Declination
Mean Declination
How to apply Mean Declination In mainland Nova Scotia, we have an approximate
20° west ‘mean declination’When we apply magnetic information (compass) to
a map, we have to subtract that 20°When we apply map information to a compass, we
have to add 20°
MAP → +20 ° → MAGNETIC
MAGNETIC → -20° → MAP
4. Continue on original course
Staying on course while going around barriers
Direction of travel 20°
1. Stop at barrier
2. Pick landmark on other side
3. Walk around the landmark
Direction of travel 20°
Going around trees
Staying on course while going around a barrier you can’t see through
Direction of travel 20° Walk to barrier, and flag or mark point
Check back bearing 200°Resume direction of travel 20°
290°100 Paces
20°Until the barrier
is cleared
110°100 Paces
Map
&
Compass Field Exercises
Field ExercisesPacing: measuring how many steps
you take to measure 100m.TrianglesStraight navigationPole navigationNavigating a pre-plotted course on a
map (afternoon)
What you are looking for??
Good luck, have fun and be safe!!
We will see you on Saturday morning at __________!!
Introduction to GPS’sTool that can calculate your location on earth by
reading satellite signals in the skyAdvantages: can tell you where you are in grid
numbers◦Can show you the path that you took◦Can input pre-determined locations, then allow the
GPS to guide you to themDisadvantages: battery operated◦Needs access to satellite input (clouds, tree cover,
…)◦Shows you the path, not the obstacles (unless you
have a new model that has maps incorporated)
Introduction to woodsloreStaying safe: what should you bring in
with you◦Compass◦Fire tool (mandatory)◦Whistle (mandatory)◦Water◦Large orange garbage bag
WaterLeave no Trace
Triangulation “how to find yourself on a map”
Triangulation requires good map reading skills.
You need to be able to recognize landmarks out in the field, and relate them to symbols/points on your map.
You pick three distinguishable landmarks, then take a compass bearing pointing at them, then mark them on your map.
Where the three lines intersect, is where you are standing.
ABCDEFGHIJKLM
3 - gradual, consistent slope5 (or 8) - draw or valley with stream13 (or 4) - cliff face12 - hill with ridge9 - spurs on a mountainside10 - a depression4 (or 13)7 - Steeper slope high, gradual low1 - consistent slope2 - gradual slope high, steeper low11 - a saddle between two hills8 (or 5)6 - simple round hill