Map and Compass
Map and Compass
• One of the Ten Essentials
– Map and Compass
• A GPS isn’t always the answer
– Subject to
• Signal
• Batteries
• User knowledge
The Compass
• How does it work?
– Magnetic Fields of the Earth
– Directed at Magnetic North Pole
Compass
• What’s it Good for?
– Compass by itself to walk in a straight line on
a heading
• With a Map
– Find where you are
– Find where you’re going
The Compass
Compass Circle has 360
N
•Directions correspond to a degree
heading
•North = 360º or 000º
E
W
•East = 90º
•South = 180º
•West = 270º
S
The Map
• Second part of Essential
• A picture of your world
The Map
•Many different kinds of maps
•Road maps like the AAA
•Aviation Maps
•Nautical Maps
•US Geological Survey (USGS) maps
•USGS Maps are what we use most for hiking
•1” inch = 24,000 feet’
•Map lines and border are aligned with True North
The Map
• Legend
– Somewhere on the map that describes all the
information used on that map
•
•
•
•
•
Symbols
Scale of Map
Distance Scale
Compass Rose
Date of Data
The Map
• Symbols
=Mine
=Year Round Stream or River
=Seasonal or Dry Stream or River
=Year Round Lake
=Seasonal or Dry Lake
=Structure
=Paved Road
=Dirt Road
=Trail
The Map
• Symbols
=Railroad
=Vegetation
X
=Peak
=Church
=School
The Map
•Contour Lines
•Show Elevation
•More Importantly – show
change in elevation
Steep – Contour Lines close together
Relatively Flat – Contour Lines far apart
The Map
Map Legend
Data Date
Distance Scale
Compass Rose
The Map
•Coordinates
•Determine a position on the map
•Different Coordinate Systems
•Longitude
•Has 180º
•000º at Greenwich England
•Measured East - West
•Latitude
•Has 90º
•00º at Equator
•Measured North - South
The Map
Latitude
Longitude
The Map
Latitude and Longitude are measured in Degrees º, minutes ‘, seconds”
Can also be measured as Degreesº, Minutes ‘.000 or
Degreesº.000
Each Degree, º, is divided into 60 Minutes, ‘
Each Minute , ‘ , is divided into 60 Seconds, “
33º27.000’ or 33º27’00” N
117º09.000’ or 117º09’00” W
The Map
•Can also use UTM grid system
•Consists of 6 digit number to determine your position
•Both Lat/Long and UTM can be found on many USGS Maps
The Map and Compass
Together as a Tool
•Use the map and the Compass together to:
•Find where you’re at
•Find where you’re going
•Also:
•How hard is your hike
•Can I make it in the time I have
•Where is the best campsite
•Where is water
The Map and Compass
Together as a Tool
•To use the map and the compass together you
must first get them looking at the same North
•Map Aligned with True North
•Compass aligned with Magnetic North
•Difference is caused by magnetic fields of the
Earth
•You must “Orient” the map
•Align the map with Magnetic North or
•Align the compass with True North
The Map and Compass
Together as a Tool
•Map may have a Compass “Rose” as on our map
•Or it may simply tell you what the deviation is
The Map and Compass
Together as a Tool
•Orienting the Map with the Compass Rose
•Line up the edge of your compass (which reads
Mag N) with the Magnetic North, MN, line on the
compass rose
The Map and Compass
Together as a Tool
•Now rotate the map
until the index lines
up with the North
needle
•Now your map is
oriented to Magnetic
North and can be
used with your
compass
The Map and Compass
Together as a Tool
•Orienting the Map without the Compass Rose
•Difference between Magnetic North (compass) and
True North (Map) is given as a Deviation or
Declination value East or West
Declination = 13º E
The Map and Compass
Together as a Tool
Note the difference and adjust the dial on your
compass so the North reference is now True North
•Rule is:
• “East is Least”
•Subtract Deviation from 360º
•“West is Best”
•Add Deviation to 360º
Declination = 13º E
The Map and Compass
Together as a Tool
• “East is Least”
•Subtract 13º East Deviation from 360º
•347º
•Set 347º on the top of your compass dial
347
360
Declination = 13º E
The Map and Compass
Together as a Tool
OR
347
347
• Now align the edge
of the compass with
any North-South line
on the map
•The edge of the
map or a line of
longitude.
Declination = 13º E
The Map and Compass
Together as a Tool
Declination = 13º E
347
OR
347
• Rotate the map
and compass until
the needle is aligned
with the index set at
347º
The Map and Compass
Together as a Tool
• One other way to
orient a map is to
line it up with known
features on the map
with known features
you see such as
lakes, peaks, roads,
etc..
The Map and Compass
Together as a Tool
• For example you
see a road to your
left and a peak
behind you you can
rotate the map to
match what you see.
The Map and Compass
Together as a Tool
• Now the Map and
Compass are ready
to use together as a
tool to find where
you are, find where
you are going or
identify any other
feature you may see
like a lake or peak.
The Map and Compass
Together as a Tool
•To determine your location look for a prominent feature
you can match to the map.
•Take your Compass and point the index at the feature.
•Now rotate your dial until 360º is aligned with the North needle
•The heading lined up with the index is your bearing to that
feature.
•In this example - 190º
The Map and Compass
Together as a Tool
•Note that bearing
•Now do the same thing with another known feature on
the map
•In this example - 345º
The Map and Compass
Together as a Tool
•Where the bearing lines intersect on your map is your
approximate location
•The more features you use the more accurate your
position will be.
•This is called “triangulation”
•A GPS does the same thing with satellites
The Map and Compass
Together as a Tool
•Bearings to different features give your approximate
location
The Map and Compass
Together as a Tool
•Now you can use this location to get a heading off the
map to where you might want to go
•For example the heading from this location to the mine
is approximately 165º
The Map and Compass
Together as a Tool
•Now an exercise
•You are standing somewhere on the map
•You see Nielsen Peak and take a bearing of 165º
•You see a small lake and the bearing is 097º
•You see the Gaging Station and the bearing is 180º
•Where are you????
The Map and Compass
Together as a Tool
•Now an exercise
•You are standing somewhere on the map
•You see Nielsen Peak and take a bearing of 165º
•You see a small lake and the bearing is 097º
•You see the Gaging Station and the bearing is 180º
•Where are you????
•You are at the Cemetery
The Map and Compass
Together as a Tool
•What is the Latitude and Longitude of your location???
The Map and Compass
Together as a Tool
•What is the Latitude and Longitude of your location???
•N33º29’32”
•W117º08’28”
The Map and Compass
Together as a Tool
•Now another exercise
•You are standing somewhere on the map that is a high
place
•You see a mine and take a bearing of 070º
•You see a bend in a river and the bearing is 004º
•You see Nielsen Peak again and take a bearing of 111º
•Where are you????
The Map and Compass
Together as a Tool
•Now and exercise
•You are standing somewhere on the map
•You see Nielsen Peak and take a bearing of 165º
•You see a small lake and the bearing is 097º
•You see the Gaging Station and the bearing is 180º
•You are on the small peak halfway between Hwy 15
and the edge of the map about 2 inches from the
bottom
The Map and Compass
Together as a Tool
•What is the Latitude and Longitude of your location???
The Map and Compass
Together as a Tool
•What is the Latitude and Longitude of your location???
•N33º27’08”
•W117º09’12”
The Map and Compass
Together as a Tool
•From your location you want to go to the intersection
of Via Novillo and Camino Estribo where the cars are
waiting.
•What is the heading?????
The Map and Compass
Together as a Tool
•From your location you want to go to the intersection
of Via Novillo and Camino Estribo where the cars are
waiting.
•What is the heading?????
•Approximately 342º
The Map and Compass
Together as a Tool
•What is the Latitude and Longitude of the cars???
•N33º28’21”
•W117º09’37”
The Map and Compass
Together as a Tool
•This has been a lot of information but we hope you
now appreciate the usefulness of the map and
compass as tools by themselves and as a backup to a
GPS