Chapter 8: Outdoor Preparedness
Plot Your Progress
As you hike into unfamiliar terrain, you can keep your bearings
by taking frequent compass readings and plotting your progress
on a map.
- Note key points, such as stream crossings, to help you
find your way back.
- Pay particular attention when you reach a high point
at the top of a ridge; use the elevation to locate landmarks visible from there.
Learning to set a course and take bearings takes study and
practice. The best way to become proficient with a compass
is under the guidance of an experienced individual.
The Global Positioning System (GPS)
The Global Positioning System (GPS) is a navigation system based on a network of 24 satellites. Users with a GPS unit can determine their exact location (latitude and longitude) in any weather conditions, all over the world, 24 hours a day.
- GPS satellites circle the Earth twice a day
and transmit information to Earth. GPS
receivers use this information to calculate
the user’s location by comparing the time
a signal was transmitted by a satellite
with the time it was received. The time
difference tells the GPS receiver the
distance from the satellite. By calculating
the distances from several satellites, the
receiver can determine and display the
user’s location on the GPS unit.
- Once the user’s position is determined, a GPS unit can calculate other information—
bearing, trip distance, distance to destination, sunrise and sunset times, and more.
- GPS receivers are accurate to within 15 meters (49 feet) on average. Certain atmospheric factors and other sources of error can affect the accuracy. Accuracy can be improved with a Differential GPS (DGPS) or WAAS (Wide Area Augmentation System).
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Personal Locator Beacon
Personal locator beacons (PLBs) provide a distress and alerting system for use in a life-and-death situation. A PLB is a small transmitter that sends out a personalized emergency distress signal to a monitored satellite system. When you buy a PLB, you must register it with the National Oceanic and Atmospheric Administration (NOAA). PLBs are a highly effective and internationally recognized way to summon help. |
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