Training Network: Wilderness Survival | Fitness Training  
Fitness Training
 

The Sport:

  • Orienteering History
  • Orienteering Overview
  • Course Setup
  • Officials
  • Start/Finish Areas
  • Course Safety
  • Control Point Guidelines
  • Map Symbols
  • Orienteering Techniques
  • Civilian Orienteering

    The Skills:

  • Maps
  • Marginal Information and Symbols
  • Grids
  • Scale and Distance
  • Direction
  • Overlays
  • Aerial Photographs
  • Navigation Equipment and Methods
  • Elevation and Relief
  • Terrain Association
  • Navigation in Different Types of Terrain

  • Field Sketching
  • Map Folding Techniques
  • Units of Measure and Conversion Factors

  • Base Lines

    In order to measure something, there must always be a starting point or zero measurement. To express direction as a unit of angular measure, there must be a starting point or zero measure and a point of reference These two points designate the base or reference line. There are three base lines— true north, magnetic north, and grid north. The most commonly used are magnetic and grid.

    a.   True North. A line from any point on the earth's surface to the north pole. All lines of longitude are true north lines. True north is usually represented by a star (Figure 6-1).

    Figure 6-1. Three norths.

    Figure 6-1. Three norths.

    b.   Magnetic North. The direction to the north magnetic pole, as indicated by the north-seeking needle of a magnetic instrument. The magnetic north is usually symbolized by a line ending with half of an arrowhead (Figure 6-1). Magnetic readings are obtained with magnetic instruments, such as lensatic and M2 compasses.

    c.   Grid North. The north that is established by using the vertical grid lines on the map. Grid north may be symbolized by the letters GN or the letter "y" (Figure 6-1).

    Back to Direction

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