September 16, 2005

Donated equipment benefits region's GPS users

by K.C. Jaehnig

CARBONDALE, Ill. -- Southern Illinoisans — from geocache hobbyists searching out "treasure" with hand-held global positioning system units to ambulance drivers hunting down rural addresses — will benefit from a continuously operating reference station given to Southern Illinois University Carbondale by Kara Co. Inc., a measuring systems supplier headquartered in Countryside.

Basically a small antenna set atop the Engineering Building's southwest tower, the station snags radio signals sent from Navstar satellites orbiting overhead, just as any GPS receiver does.

But because it stays in one place and "knows" its own location, the station can correct distance calculation errors in these signals caused by such things as satellite data glitches or the signals slowing as they go through the atmosphere or interference from large buildings. This makes the station far more accurate than mobile receivers. When it broadcasts a radio signal of its own, mobile receivers that pick it up give more accurate readings, too.

"With survey-grade equipment, you can get a location within a couple of centimeters," said Roy R. Frank Jr., the Department of Civil Engineering's survey expert.

While Illinois has several such base stations, the southern part of the state "is a big hole," Frank said.

"We're going to fill much of that hole. The CORS (the acronym for continuously operating reference station) will be the base station for everyone for 45 miles around, and the information will be available on the Internet, too.

"SIU is first, but my eventual hope would be to get one of these at Rend Lake College, one at Southeastern Illinois College and one at Shawnee Community College. That would form a big diamond shape that would give all of Southern Illinois extreme coverage."

As GPS technology has become both more advanced and cheaper, uses have mushroomed. Businesses such as Federal Express rely on it to track their delivery trucks. Farmers can pinpoint areas in their fields that need more fertilizer or greater weed control. Police, fire and ambulance services know just where to go when 911 calls come in. Geocaching, a treasure hunt using geographic coordinates as clues, draws players worldwide. Parents have even used it to keep track of pesky teens.

"The possibilities are just limitless," Frank said.

"Anytime you need to know exactly where you're at — that's what GPS is for, and the CORS will let you do that with a greater degree of accuracy."

Closer to home, Frank described the station as a huge benefit for SIUC's surveying program, the only one in the state leading to land surveyor licensure.

"We do extensive mapping in our program, and getting students out in the field practicing what professionals do helps their comprehension," Frank said.

Students are working with professionals on the University's new campus map, remapping the bottom of Crab Orchard Lake (a project Frank's classes undertook in the early ‘90s without GPS) and will soon start on a three-dimensional map of the River to River Relay an annual, 80-mile run that takes teams from just north of Wolf Lake east to Golconda. They also carry out small mapping projects for groups that can't afford to pay for such services.

"We have a small amount of donated GPS equipment, so with the CORS (being a permanent base station), it will free up one of our receivers, which means more students will be able to use our equipment," Frank said.

"GPS makes our life so much simpler. It used to be when we would have to run standard surveying equipment that something might take two to three days or longer. With GPS, we can do it in two separate one-hour sessions and be more accurate. GPS just has so much more precision."

Serving others is among the goals of Southern at 150: Building Excellence Through Commitment, the blueprint for the development of the University by the time it celebrates its 150th anniversary in 2019.