Understanding GPS Systems

Understanding GPS SystemsThe Global Positioning System (GPS) uses signals from satellites in Earth's orbit to identify the latitude, longitude and altitude of the user. Hand-held GPS units are popular with hikers and backpackers to plot routes and track their course.

GPS Satellite System

Originally designed for the U.S. military, GPS technology uses satellites orbiting the Earth to pinpoint your location anywhere on Earth.

How GPS Works

According to REI, a GPS system uses signal from three or more satellites to locate your position on land or sea.


GPS systems are very accurate. REI says to expect a GPS system's accuracy to be within 20 to 30 feet. Some advanced systems have accuracy of 3 meters or less in ideal conditions.


Because a GPS unit requires satellites to get an accurate reading, obstacles such as tall buildings, high canyon walls and dense forests can block signal reception.


GPS systems should never replace a map and compass. GPS systems can run out of batteries, fail to get a signal or malfunction.

Article Written By Wren Mcilroy

Based out of Salt Lake City, Wren Mcilroy has been writing outdoor recreation and travel-related articles for 3 years. She holds a Bachelor of Science in psychology and biology from Winona State University in Minnesota.

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