GPS in the spotlight.

50th GPS Satellite Launched

The 50th Global Positioning System (GPS) satellite was successfully launched on March 20, 2004. The satellite, known as GPS 2R-11, departed from Florida's Cape Canaveral at 12:53 p.m. EST. GPS 2R-11 was manufactured by Lockheed Martin and replaced GPS 2A-19. The latter satellite is 11 years old and its navigation data unit is suspected of being faulty. GPS 2R-11, as it orbits 11,000 miles above the earth, will assume the Plane C, Slot 3 position in the GPS network.

Because of GPS 2R-11's significant status as the 50th GPS satellite, it was given a commemorative role. GPS 2R-11 memorializes Dr. Ivan A. Getting, one of the founders of GPS, with a special inscription. Engraved on one of the spacecraft's weights is Getting's name and his famous description of GPS satellites. It reads: "Lighthouses in the Sky Serving All Mankind."

The next GPS satellite launches are scheduled for July and September 2004.

Team Caltech converted this 1996 Chevy Tahoe into an autonomous robotic vehicle named "Bob" for the DARPA Grand Challenge. Photo compliments of DARPA.

GPS Guides Robot Vehicles

On March 13, 2004, three shirtless university students stood in a row with letters painted on their chests spelling out "BOB." Although they looked like typical college sports fans, they were actually cheering on an autonomous robotic vehicle.

"Bob" was one of 15 unmanned ground robotic vehicles guided by GPS technology that participated in the DARPA Grand Challenge in California. This event, sponsored by the Defense Advanced Research Projects Agency, was intended to stimulate the development of robotic technology for future American military applications. DARPA offered a $1 million cash award to any team whose vehicle could successfully navigate a 250-mile course through the Mojave Desert to Las Vegas within its proposed time limit.

But no vehicle even made it to the eight-mile mark.

"To release a vehicle and ask it to find its way across the desert is extraordinarily difficult. [Even] a human being would find it difficult," said Peter Williams, PhD, director of advanced programs for NavCom Technology Inc., Torrance, Calif., one of the companies whose products were used in the challenge. Six of the 15 qualifying teams in the challenge chose NavCom's Starfire Network to provide their vehicles with decimeter positioning accuracy. Team Caltech, the force behind "Bob," used the NavCom SF-2050G (a pole-mounted DGPS receiver). Dave van Gogh, leader of Team Caltech, said that the Starfire Network gave his team "the ability to accurately measure the position and velocity of our vehicle."

In fact, all of the vehicles entered in the DARPA Grand Challenge represented advances that have been made possible by GPS. According to Williams, "Positioning and navigation is a fairly well-established capability... once [the vehicles] had the GPS system onboard, the positioning itself and interfacing with the positioning sensor was not the biggest issue." Two of the vehicles that traveled the farthest dropped out of the trial because of mechanical-not electrical-failures.

On the day of the Grand Challenge, spectators crowded into the stands at 5 a.m., enthusiastically cheering on the self-driven vehicles. The vehicle created by the Red Team from Carnegie Mellon University had the best showing, making it to mile 7.4 before it got stuck and caught on fire.

Although these results may seem superficially disappointing-and no one walked away with a million dollars-the DARPA Grand Challenge was a historic competition that unleashed incredible creativity and robotic development.

And what about the fiercely supported "Bob"? Well, Team Caltech's "Bob" went off the course at mile 1.3 and got trapped in a barbed wire fence. But Team Caltech, along with many of the other teams, has declared that it is ready to start preparing for a second grand challenge--with the continued help of GPS.

"Space Contact," designed by artist Kuspi, grew to resemble a docking station for UFOs in Berneck, Switzerland. Its diagonal measured 250 meters (roughly 820 feet). Photo compliments of Leica Geosystems.

LandArte Sprouts in Switzerland

Last year was the bicentennial of the Swiss canton (or state) of St. Gallen, located in the Alpine Rhine Valley. With industry manufacturer Leica Geosystems headquartered in St. Gallen's city of Heerbrugg, the company participated in the canton's plans to commemorate its 200th anniversary. One plan for the celebration resulted in LandArte-awe-inspiring artworks composed of growing plants in farmers' fields. But how was Leica Geosystems involved in what seems to be an agricultural project?

Leica Geosystems supplied the technology and equipment to make Swiss potter Bernarda Mattle's idea of LandArte a possibility. The project required a combination of art and technology to create massive artworks out of farmers' crops. At the completion of LandArte, 13 crop images were flourishing. And more than 200,000 visitors gathered to see them.

Erna Reich's "Humans Leave Tracks" was the largest LandArte work, spanning more than 3 kilometers (almost 2 miles). The dark footsteps in this work plodded across the three villages of Frumsen, Sax and Gams. Photo compliments of Leica Geosystems.
Artists from Finland, Lichtenstein, Austria and, of course, Switzerland were asked to design the images for LandArte. Then local surveyors FPK & Partners, landscape architect students from the Rapperswil University of Applied Sciences, and farmers became involved in the transfer of the artists' sketches to the fields. The artists' drawings were digitized and transferred into a local grid to be set out. A Leica GS20 (a handheld professional data mapper) was used for most of their stakeout work; they also occasionally used the Leica GPS System 500 for areas of the artwork that required greater precision. Some crop images were planted with guidance from a Leica Dozer GradeStar Indicate system.

LandArte evolved throughout the spring and summer, changing color with the seasons. The visitors who came to enjoy the art walked along the valley and took the railway cable up the mountains for a better view. And in the fall, the harvest of LandArte yielded wheat, corn, marigolds and blue phacelia, a natural fertilizer.