March 29, 2020

GPS: cellular phones of wilderness> Hikers mapping routes, hunters plot positions

If the world didn’t already seem to be a much smaller place, it certainly is now.

Thanks to satellite technology and the surging popularity of Global Positioning Systems, it’s becoming more and more difficult to find yourself totally isolated these days.

GPS units are the cellular phones of the wilderness. Hikers use these cell phone-sized receivers to map routes, hunters use them to plot their positions and that of their game in woods and fields, and fishermen use them to mark favorite spots – from deep holes in bays, lakes and oceans to uncharted ponds and streams.

“What you’re eventually going to have is someone with a cell phone calling the state police with their latitude and longitude and saying `I don’t have a clue where I’m at. Come and get me,’ ” said Wayde Carter, a district game warden for the Wesley patrol in Washington County. “And they’ll be able to find them.”

Carter, who has owned his own GPS for a couple of months, patrols territory which spans seven towns, six of them unorganized, and includes the Stud Mill Road and Route 9.

“If you know what you’re doing with them, you can use them for an endless number of things. I’m real anxious to use mine over the next year or so,” he said.

GPS units receive signals from various military satellites 12,000 miles above the earth and use at least four signals to calculate the user’s position by latitude and longitude or by the Universal Transverse Mercator, which represents latitude and longitude as grid coordinates (east and north) on a cylindrical surface. A UTM map divides a region into 1,000-meter square grids.

Depending on their cost, GPS units provide added information such as distance (in miles or kilometers) to a position, direction, bearing, speed in miles (or km) per hour, military and Greenwich mean time, lunar phases, the time of sunrise and sunset, and even tidal information – and they’re continually improving.

“They’re just like computers in that as soon as you buy a brand, spanking new unit, it’s obsolete,” said Mark LaCasse, store manager at Van Raymond Outfitters in Brewer.

The VCR boom of the ’90s

When they were originally introduced to consumers in the late 1980s, basic GPS units cost as much as $2,000. But just like VCRs and compact disc players, the quality and features have increased while the prices have drastically decreased.

“I’d say within the last year to 18 months, the price has come down substantially,” LaCasse explained. “They got real popular this Christmas. We’ve sold out a couple of times in the last few months.”

It’s no wonder, since most good units with plenty of features cost only $150 to $250.

The popularity of the slick units, which look either like cell phones or fish finders with a square screen showing the user’s position (with an X, stick figure, or fancier icon) and other landmarks such as the user’s car, a nearby lake, stream, or rock formations, seems to be up all over the state of Maine.

Dan Devries, the manager of Cadillac Mountain Sports in Bar Harbor, used one word to describe the popularity of the two GPS units his store sells.

“Wicked!” he said without hesitation. “They’re kind of pricey so we never have too many on hand, but we’ve never kept them in the store longer than two weeks before selling them.”

While LaCasse sells most of his units to hunters and fishermen, Devries said most of his GPS customers are hikers, who use them to map out trails they want to take and/or to keep track of their routes. Outdoor recreationalists aren’t the only people putting GPS units to good use.

More and more wardens like Carter are using them. The Maine Army National Guard uses GPS technology to mark all its helicopter landing sites and the U.S. military may eventually use GPS technology to implement a global early-warning system for missile and other attacks.

“I’ve heard rumors that drug dealers use these to mark the spots where they’re growing marijuana and then take different routes to the spot so they don’t wear paths or tip off police,” said Carter.

Carter said he knows wardens who use GPS units to plot hazards and obstructions on bodies of water so they can speed through them, frozen or not, in any kind of weather without running aground.

A particularly useful application of GPS technology is in search and rescue.

“[Sergeant] Roger Guay is one our GPS instructors and is on the Warden Service Overhead search and rescue team,” said Carter. “They can bring GPS units back to a command center, download it to a computer, and it will show the line and the track a searcher walked. They put them all on a map and overlay them to figure out what areas have been searched. It will show any gaps in the search area.”

Maine roots

GPS’ roots go back 16 years, when the University of Maine was one the schools that helped build the passive GPS system from the ground up.

“It’s a long story,” said Professor Alfred Leick, UMaine professor of spatial information, science and engineering. “My specialization is satellite positioning. I have known about GPS since 1978 and did my first experimentation with GPS at MIT in 1982.”

Leick is understandably proud of the University of Maine’s involvement in pioneering GPS technology.

“We’re probably the first school in the United States that gave a dedicated course in GPS positioning,” he explained.

Currently, Leick teaches individual courses in GPS on the internet on an experimental basis.

“What I’m currently trying to do is establish internet courses on GPS. A year from now, I expect to have a regular internet course,” said Leick, who is also working on combining GPS and its Russian equivalent: CLONASS.

GPS technology resulted from the U.S. military’s desire to have a precise targeting system during the cold war which would make it easier to refuel airplanes in flight, pinpoint targets, locate downed pilots, and position submarines.

“The American pilot who was shot down in Bosnia had one with him. That’s how he was found so quickly,” explained Leick.

There are two types of GPS signals: encrypted, which the military uses, and selective availability, which contain built-in errors that falsify the exact position of satellites so they can’t be tracked.

There are also two types of GPS users. One is hunters and outdoorsmen who use the units for location and don’t mind the built-in error.

“There is supposedly an error of plus or minus 100 meters, but I have rarely seen it more than five or six,” said LaCasse. “The altitude is what I find to be way off at times.”

The second group is the military and scientists like Leick, who want to find specific points on huge tracts of land hundreds of miles across within fractions of an inch.

Leick, who admits he’s not an outdoorsmen, owns a couple of GPS units “to play around with.” He also works with $20,000 GPS units at the university which are licensed to decode encrypted military signals.

“The application of GPS technology is without limits,” said Leick. “This has so many practical applications in our society.”

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