Map, Compass & GPS

Map, Compass & GPS
Wild flowers along Fall Creek on the way to the Green Lakes - Oregon

Wednesday, October 16, 2013

Why Humans Get Lost

Tia Ghose is a Live Science staff writer who authored an interesting article (March 2013)
titled Why Humans Get Lost.  Through interviews and case studies she evaluates what causes hikers to get lost in the backcountry.  She identifies that in some case carelessness is a contributor as is our loss of the natural ways of navigating by the stars and sun.  At one point in a section of the article called “Use it or Lose IT” she states:

“But the sense of direction may also wither with disuse. Small studies have found that using a GPS for just a few hours seems to impair people's navigational skills in the short term, …many people get lost because they simply aren't paying attention….”

In navigation classes and seminars I frequently comment that navigation is a perishable skill.  It is a skill that requires practice and thought.  Navigation skills are not instinctive but are learned and developed.

Today, the principle components of backcountry navigation consist of:

1.    A declination adjustable magnetic compass

2.    A quality map

3.    A GPS receiver

Your grandfather’s compass was a wonderful tool in its day but should be replaced by a declination adjustable compass.  Such a compass eliminates the guess work associated with calculating for declination.  Viable compasses are made by Brunton, Suunto, and Silva.

For example, the Suunto M2 can quickly be adjusted for declination by the movement of a set screw to cause the rotating compass dial to turn.   With such adjustment the rotating dial provides information in degrees true and now matches the map.  (Keep in mind that the red magnetic needle still points to magnetic north.)

Quality maps can be found at your local outdoor retailer in several forms.  For example,s National Geographic publishes traditional paper maps and also offers mapping software listed by individual states.  I also recommend’s Map Pass.  A $30 annual subscription lets you print maps at home on your PC.  It is a robust option that allows the user to select map scale, aerial imagery and grid (e.g., latitude and longitude or UTM).

Topographic maps provide a sense of the “lay of the land.”  The lay of the land includes the
rise and fall of ground topography, the location and direction of water sources and manmade travel aids such as roads and trails.  These maps also identify hand rails..  Hand rails are the hiker’s visual cues of the land.  Hand rails include linear features such as roads, streams, ridgelines, trails and fence lines. Hand rails must be visible on the map to be of use.

Before departing on a wilderness trek, careful studying of the map coupled with a compass is the first step in developing a mental map.

National Geographic’s educational web site suggest that mental maps are:

“Mental maps provide people with essential means of making sense of the world and of storing and recalling information about the patterns of Earth’s physical and human features. These maps represent ever-changing summaries of spatial knowledge and are indicators of how well people know the spatial characteristics of places

A mental map is the ability to remember key land marks and their features.  For example, remembering that to the east of the ridgeline trail, is a steep drainage with a slow moving stream, a stream that flows adjacent to a camp site.  It takes practice but such study develops the hikers mind and makes navigation a bit more logical in the field.



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