Lesson 14 Charting a Course

What is orienteering Using a map and compass to find a way through a wilderness or trial Pathfinding The are of finding your way through an unknown territory using a map, compass or GPS

Who should be interested in orienteering Hunters and anglers Outdoor sports activities – campers, hikers Equipment needs: topical map and silva compass

What is a map A reduced representation of a portion of the surface of the earth Contains representative signs called map symbols Represents all distances in the same proportion as are in the normal landscape

What map features should be considered? Type of map Topographic map – topos means “place” graphein means “t o write or draw”. Each topographic map is a drawn or photographed in a specific scale. Scale refers to the proportion between a distance on the map and actual distance

Common Scales 1 unit to 250,000 units is a scale of 1:250,000 Mapped area in 3 scales 1 unit to 250,000 units is a scale of 1:250,000 1 unit to 100,000 unitsis a scale of 1:100,000 1 unit to 62,500 units is a scale of 1:62,500 1 unit to 24,000 units is a scale of 1:24,000

What information may a map tell a hunter? 5 D’s - Description, Details, Directions, Distance, Designations Description – descriptive information about the map Towns, lakes, mountains, prominent locations Longitude degrees, latitude degree, cross marks, intersect Year the map was developed

Details Map symbols color indicate various features Black – human made features Blue – water features Green – vegetation features Brown – elevation features Human made features include such things as: roads, tracks, houses, buildings, railroads, power lines, dams, bridges, boundaries

Magnetic North

Map symbols for human-made features (black)

Map symbols

Contour intervals are printed at the bottom of the map

Directions Must know north and south on map Left margin is west, right margin is east, top is north, bottom south

Other methods of determining direction 0-360 degrees – north 90 degrees = east 180 degrees = south 270 degrees = west Other methods of determining direction Noon the sun is due south Trees have thicker foliage on south side Sticks shadow in photo at noon

Distances Located on the scales on bottom margin of the map A base plate on a orienteering compass may be used to measure distance between points Grid refers to lines drawn on a map for each degree of longitude and latitude. The grids formed all over the map represent 1 square mile on a 1:62,500 scale map

Two ways to determine distance Pacing – every time left foot hits ground is called a double step, 1,000 double steps = 1 mile Time to walk one mile, 15 minutes on a highway

Designations Places and map features are designated in various lettering styles Regular roman type is used for places, boundary lines and area names Hydrographic names are water features, usually italics are used Hygroscopic names are elevation features, they are usually block letters

What are the features of an orienteering compass? Three main parts to the Silva compass Magnetic needle Compass Housing Base Plate

Magnetic needle – north end is painted red Magnetic needle – north end is painted red. The needle always points north.

Compass housing – revolving marked with “4 cardinal points” – north, south, east, west. Is divided into degree points. Every 20 points are marked, from 20-360. Orienteering arrow points directly north toward magnetic north. Orienteering lines – parallel the orienteering arrow

Rectangular, transparent, can be turned Contains an arrow referred to as a direction-of-travel arrow. Edges are marked inches and millimeters for use in measuring on a map

The Silva system fives direction without having to figure out degrees numbers. A protractor and compass are provided in one tool so that it may be used with a map

Depends on ones location The true north is the north pole Magnet north is the compass held direction toward magnetic north pole Magnetic force of the earth pulls the compass needle out of line with true north. The angle between the two directions is called declination You can be taken off course if you depend on your compass and forget about declination If your declination is west, set your compass, then add the number of declination degrees to your reading If you get a compass reading of 282 degrees and your declination is 9 degrees west, then add 282 + 0 = 291 degrees and move your compass dial to 291 degree If your declination is east set your compass to subtract the number of declination degrees from your reading.