RELYING ON GPS
- Dick Mason
- The Observer
Global Positioning System units are extraordinary navigation tools, but they are not perfect.
Three people hunting in Northeast Oregon discovered this the hard way last weekend.
The very hard way.
The men got lost after their GPS units apparently malfunctioned. One, from Tigard, was hunting in the Mount Emily area. The other two were from San Francisco and hunting in the Eagle Cap Wilderness.
Union County Search and Rescue sent crews looking for the hunters. All were found cold and hungry but in good health. The Tigard hunter spent one night lost and the San Francisco hunters were lost two nights.
In both cases technology apparently failed them. The hunters reported they were using GPS units that malfunctioned without indicating that they had stopped working correctly.
Members of a rescue crew tested the Tigard hunter's GPS and confirmed that it was not working accurately, said Cathy Nowak of Union County Search and Rescue.
Nowak said this is the first time in the five years she has been with Search and Rescue that anyone who got lost reported a malfunctioning GPS. That this happened twice in one weekend is quite a coincidence. Nowak advises anyone using a GPS to check it periodically to make sure it is accurate.
Most problems with GPS units are the result of people not using them correctly, said Bob Nelson of Search and Rescue. On very rare occasions satellite problems cause a GPS unit to give incorrect readings. Such problems cause dramatic changes in coordinates displayed by the unit.
The global positioning system is made up of a network of 24 satellites placed in orbit by the U.S. Department of Defense. The global positioning system was originally intended for military applications, but in the 1980s, the government made the system available for civilian use.
La Grande outdoorsman Phil Gillette has used a GPS unit for years and has never experienced problems. He believes most people having problems are not using them correctly. He noted that it is important to use the equipment in open areas and not under heavy forest cover, which can impede the transmission of radio signals.
Other factors that can cause signal errors include atmospheric conditions that slow satellite signals, and things like large rock surfaces that divert the path of the signal, according to www.garmin.com.
Gillette advises people to have a good working knowledge of their GPS unit. Some buy the units and don't intend to learn how to use them until they get lost, which is a mistake said Gillette, the owner of Phil's Outdoor Surplus.
He noted that people are better served by higher priced units because they easily connect with more satellites. This provides users with a better reading of where they are.
Regardless of the qualify of your GPS unit, it is a good idea not to become too dependent on it. "A GPS is a valuable tool but it is not the only tool,'' Nelson said.
People are advised to bring a map and compass with them to complement and back up their GPS in the event of a breakdown. The likelihood of a GPS malfunction is remote. But the possibility that you may drop a unit down an embankment or that its batteries will go dead is not.
Nowak advises people to bring spare batteries even if they have new ones in their equipment. She explained that new batteries occasionally have a weak charge.
Maps and compasses are always in working order, but are of no use to those who don't know how to use them. Nowak urges everyone to take map and compass classes offered by Search and Rescue personnel or to practice periodically using maps and compasses.
Nelson is concerned that some people using GPS units have never learned how to use a map and compass. They are at the mercy of technology when navigating through unfamiliar terrain, Nelson said.
"It's is like buying a calculator before you can add, subtract and divide.''