Compass and Mapping 1
Last updated
Last updated
Have a basic knowledge of how a magnetic compass work, and be able to show the basic 16 directions shown in the compass.(i.e. North, NE, NNE…)
Be able to show the ability about the undermentioned: Key elements of the map, Conventional signs of a map
Understand how to use the Global Positioning System (GPS)
The Compass is a useful tool, especially when combined with the use of a map.
Magnetic compass, in navigation or surveying, an instrument for determining direction on the surface of Earth by means of a magnetic pointer that aligns itself with Earth’s magnetic field. The magnetic compass is the oldest and most familiar type of compass and is used in different forms in aircraft, ships, and land vehicles and by surveyors.
A compass works by detecting the Earth’s natural magnetic fields. The Earth has an iron core that is part liquid and part solid crystal due to gravitational pressure. It is believed that movement in the liquid outer core is what produces the Earth’s magnetic field. Like all magnetic fields the Earth’s magnetic field has two main poles, a north and south pole. These magnetic poles are slightly off from the Earth’s axis rotation which is used as the basis of the geographic poles, but they are close enough that the general directions with adjustments for the polar difference, called a declination, can be used for navigation.
There are mainly four points of the compass. All the other points are made by combining these four. Eg: Halfway between north and east is northeast. There are many ways to remember the order of the points. The points start at the top and go around clockwise.
Never Eat Shredded Wheat - NESW
The eight main bearings or directions are:
North: 0 Degrees
East: 90 Degrees
South: 180 Degrees
West: 270 Degrees
North East: 45 Degrees
South East: 135 Degrees
South West: 225 Degrees
North West: 315 Degrees
A map is a picture of a given area of what the ground looks like from directly above. When undertaking a journey, we need to be able to find our way around competently, sometimes in unfamiliar territory. It is then that we need to be able to use and read maps. The type of map required will depend upon the journey or destination.
A simple sketch map is maybe all that is required to find a room or building, or it may be a road map which helps you plan long distance routes across a whole country. There are also town maps and Ordnance Survey maps. All maps are drawn to a scale which means that a defined length on the map equates to a real length on the ground, for example one cm = one km.
Map symbols are the signs or diagrams shown on a map to indicate physical features. A list or 'key' of what these symbols mean is given at the same point on or in the map for identification. A number of the more common map symbols are shown below. These will be consistent on all modern O.S. maps but they might vary on other sorts of map, so it will be worth checking that on the map you are using that the symbol means what you think it does!
Participate in our mapping sessions for more information
