GPS/MODELING SOFTWARE
New Technology Gives Runners Wings
The combination of GPS and modeling software is offering new solutions to a multitude of vertical markets
By Mike Michaelson

How would you like to compete in a 194-mile relay race and never be out of breath? Or so much as even break into a sweat? It can be done thanks to virtual reality. That's the future vision for The Relay, a footrace from Napa to Santa Cruz, California. A sneak preview of the 'virtual world' was seen by some 20,000 attendees at the annual Bay to Breakers Expo held in San Francisco. The virtual world was created using a Pathfinder Pro XR with EVEREST GPS provided by Trimble Navigation Ltd. Sunnyvale, California and LandForm Gold software developed by Rapid Imaging Software, Inc. Albuquerque, New Mexico.
     Standing in front of a PC outfitted with LandForm Gold software combined with GPS positioning data collected by Trimble's Pathfinder Pro XR, runners and members of the public were able to "fly" through a lion's share of the San Francisco terrain, including a virtual trip across the famous Golden Gate Bridge in 3-D. Further, at the push of a mouse button, users could touch on any location along the race course and see latitude, longitude, and altitude data.
     "This program came about kind of concurrently," said Mike Abernathy, president of Rapid Imaging. "In 1996, we were developing LandForm Gold, and at the same time Sam Shaw, an applications engineer at Trimble Navigation, was experimenting with the use of GPS positional data in 3-D modeling. I have to give Sam the tag because he found us first."

On Your Marks!
"I was surfing the Internet one day looking for a source of 3-D terrain viewing software," Shaw explained. "I had mapped the Relay race course in 1996 using our Pathfinder Pro XR, but this year we had our EVEREST Multipath Rejection technology and I wanted to see how much we could improve the quality of the data acquired. I was not to be disappointed."
     Meanwhile, in New Mexico, Abernathy was searching for a GPS maker who was willing to experiment with his 3-D modeling tool, as well as one who was able to provide the high quality of GPS positional data that he needed.
     "We had to find a high quality of GPS data or the product couldn't perform as we wanted it to," Abernathy said. "Our software allows users to fuse different kinds of data and look at them in a very natural way-as though they were flying above the earth in a given position looking at a given set of terrain. Trimble was the only GPS maker who was sophisticated enough to appreciate what we were trying to do. And Trimble products could give us the level of data accuracy that we needed."
      According to Abernathy, LandForm Gold integrates digital elevation models (DEM); imagery, such as remotely sensed imagery; and a GPS track data file, which represents a path along true space such as, in this case, the GPS course data for The Relay race. The DEM files are available free on the Internet.
     This integration allows users to push a "play" button much like a VCR, then literally "fly" along a GPS data "track," similar to the way a monorail would travel along its track, only this "track" is built of GPS data. "This makes the high quality GPS positional data provided by the Pathfinder Pro XR very important," said Abernathy. "Without the high quality GPS data, much of the modeling is only theoretical instead of having a real world meaning."
     There are a wide variety of applications for this kind of tool," Abernathy said. "Many people use our terrain viewing software to perform mission planning for military or law enforcement applications, environmental planning and impact analysis, and extractive industries such as drilling and mining. For example, if someone is moving something illegal into this country, such as drugs, authorities can track certain routes dealers can take to avoid radar coverage. Having the GPS data for these routes can allow authorities to "fly" these areas to look for places where smugglers could land. Also, in the recent disappearance of the Air Force A-10, authorities could have assembled a GPS track of where the pilot flew and reflown his course again to determine where the best places to search were." Abernathy noted that 3-D imaging software integrated with GPS positional data might soon allow military pilots to practice missions before they even set foot in their aircraft.
     "From an operations standpoint, logistical planners will be able to use all of this data to figure out why things have come to be like they are," Abernathy explained. "With this information, planners can see what their people in the field can see, and assist them in their operations at a level never available before."
     Abernathy's product has also been used by organizations such as the Department of Justice in studying forensics associated with aircraft accidents at certain airports in the United States. "The trajectory of a plane during a crash has been mapped to determine what could have happened that eventually made that plane crash. Investigators can literally fly the same route as the doomed plane. Equipped with Trimble GPS data, LandForm can be used to improve 911 service response planning for remote rural areas. Utility companies can visualize proposed or existing routes for pipe or power lines, and even publish 3-D site models on company internets."
     Rapid Imaging was established in 1984 to explore the use of 3-D modeling technology on a PC platform, including a VRML output, which makes putting models on the Internet in 3-D possible. "Prior to this, 3-D modeling was done only on a workstation platform, but not on a PC," Abernathy said.
     "When I got started I saw the PC as an excellent tool to do this kind of analysis. OPEN GL really accelerated this application because it allowed the integration of all these data on a PC platform."

Get Set!
"The Relay relay race was an excellent test for this project, said Abernathy. "We wanted to work with Trimble to refine the integration of GPS data into a 3-D environment. We were lucky to have Sam working with us, because he appreciates the technology, and he knew what high quality data could do for us and our product. He knew he could get high quality data from the Pathfinder Pro XR, and he knew the Pathfinder Office software could allow us to download and manipulate that data into virtually any format we wanted."
      Although typical map scales used with LandForm Gold are 1:250,000 digital elevation models, the Relay race was mapped to 1:24,000, 7.5 arc minute quadrangle digital elevation models.
      "We were able to use the Pathfinder Pro XR to drive along the course to collect data that was accurate to better than one meter, so when Sam got to the Golden Gate Bridge, he made Jeff Shapiro, the race director, get out of the car, put on rollerblades, strap the Pro XR to his back, and collect data along the pedestrian platform which runs along the length of the bridge. The data is so accurate that you can see in the map where this side trip took place, as well as where he skated around the north and south towers," Abernathy explained. "It's remarkably accurate. The result of this high quality data is that the runner gets a true picture of the course without ever having to set a foot on it."
     The Bay to Breakers Race represents a 194-mile course that is broken down into 36 legs, each leg representing a segment that an individual runner covers in the race.
     "The data was collected for all of the legs using the Pathfinder Pro XR," said Abernathy. "That data was sent to me on disks. We also overlay topographic maps obtained from the USGS. Satellite imagery was provided by CNES/SPOT Image (Reston, Va.)." The resulting images, including the GPS track data collected by the Pathfinder ProXR, can be viewed at the LandForm Website URL: http://www.landform.com/lfrelay.htm.
      Abernathy notes that demonstration CD-ROMs of the race course will be made available at the end of July.

Go!
"I see a big future in this type of software and data in a lot of areas where data couldn't be visualized in practically any other way," Abernathy explained. "Can you imagine designing a ski resort with this kind of tool? That'll be exciting."
     Abernathy stopped and thought for a moment, almost as if he were predicting the future of his brainchild.
     "Can you imagine giving someone a virtual tour of an area, particularly in education, where there is a geographic element to information?" said Abernathy. "GPS would provide a guide in the lay of the land in a way that hasn't been possible before, in form as well as accuracy. I think that's incredible, and that's where I think these tools come in - the integration of high-precision GPS data with 3-D modeling tools."
     Remarkably, the Relay 3-D map course took only one day to build after the data was collected. "After the GPS data was collected and processed with the Office software, it just plugged right in. It took some time to validate our format," said Abernathy. "Then, as they say, we were off and running."

About the Author:
Michael W. Michelsen, Jr. works in the marketing communications department at Trimble Navigation Limited.

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