- SPECIAL REPORTS
- THE MAGAZINE
Well in advance of Tiger Woods’ run for another major victory during the 2008 U.S. Open at Torrey Pines Golf Course near San Diego, Calif., the United States Golf Association (USGA) looked to create an entirely different buzz around this prestigious course. Seeking a new way to draw a younger, more international audience into the game, the USGA and IBM teamed up with Terra Imaging, a La Jolla, Calif.-based firm skilled in photogrammetry and 3D GIS mapping technology, to provide viewers, professional golfers and analysts with an unprecedented visual experience during and after the event.
The dramatic 3D imagery of the course--which Terra Imaging calls 3D Golf Course--was made possible through the firm’s strategic relationships with Leica Geosystems and Microsoft Virtual Earth. In the two weeks prior to the June tournament, the project team developed a high-resolution 3D terrain and imagery model of Torrey Pines’ rugged coastline fairways, spectacular multicontoured greens and perilous roughs and sand traps. “Our job was to provide incredibly precise range distances, assist with hyperaccurate play-by-play visuals and increase precision for player statistics,” says Karl Engstrom, chief technology officer for Terra Imaging. “Our horizontal mapping accuracies had to have millimeter or subcentimeter precision.”
From dusk to dawn, dodging errant tee shots and high-pressure sprinklers, the survey team took a very different walk around this prestigious golf course carrying some of the industry’s most advanced laser and mapping technologies to create the advanced 3D topographic model. More than just a pretty picture, the resulting 3D terrain and imagery model became an integral part of the tournament for golfers and golf enthusiasts alike.
Above ParTorrey Pines Golf Course is located on the coastal bluffs of the Pacific Ocean in La Jolla, a 20-minute drive from downtown San Diego. While there are two 18-hole courses at the site, the 2008 U.S. Open participants teed up on the more than 7,600-yard South Course.
To create the complete high-resolution, high-accuracy GPS model required by the USGA and IBM, Terra Imaging opted for a mixture of high-resolution airborne LiDAR data along with high-definition 3D terrestrial LiDAR instead of the more conventional hands-on mapping and digital re-creations. Using this combination of laser and imaging tools, as well as reflectorless laser rangefinders, GPS, mapping software such as ESRI’s ArcGIS, and proprietary mapping software from Terra Imaging, the team would be able to map the golf course terrain in 3D with much greater accuracy and speed. Portable hand-held reflectorless lasers were used to capture geologic features, such as contacts (points where two different types or ages of rock meet) and terrain, and these features were combined with digital elevation models in ArcGIS software. The airborne imagery then provided the accurate visualization to the 3D model.
“We chose to use airborne LiDAR and terrestrial LiDAR to create a test model that was composed of the highest possible horizontal and vertical accuracies,” Engstrom says. “Using both airborne and terrestrial LiDAR allows us to capture and render the very high-resolution 3D terrain and 3D object models.”
Better yet, the terrestrial high-definition LiDAR system works well at night allowing the survey team to avoid the daytime crowds on the course--though they did run into a few obstacles during their nocturnal adventures.
Fore!The eight-person survey team comprised professionals from Leica Geosystems (San Diego), Surveyors Service Co. (SERVCO--a Leica distributor based in Costa Mesa, Calif.) and Terra Imaging. “Our core technology focus is to acquire and create the highest-resolution mapping data ever developed for the golf course industry,” Engstrom explains. “We are pushing the envelope of 3D GIS and visualization technologies specific to the next generation of Web/mobile devices and leveraging software development way beyond Web 2.0 functionality. Leica represents the leading technology in GPS and HD LiDAR scanners, so we chose them as our core partner for all 3D Golf Course mapping.”
Given the number of people attending the U.S. Open as well as the practice and preliminary rounds, the team opted to perform the majority of the field surveys and laser scans in the late afternoon and evenings during the two weeks prior to the event. Even then, they had to dodge golf balls, sprinklers and the occasional nighttime security guard to set ground control. “Golf course security guards became our enthusiastic audience as the laser scanner’s piercing green light makes for a spectacular light show,” Engstrom says.
“The goal was to set three stakes per green and larger targets throughout the rest of the course,” Engstrom says. “As the stakes were prepared, another survey team would set up the Leica HD LiDAR scanner to capture the green topography.”
Each setup required approximately 45 to 60 minutes per green, and every scan captured about five million points. Of course, unexpected circumstances had a way of occasionally pushing the survey teams just a bit faster. “More than once, we were caught when an ‘unplanned’ sprinkler fired off,” Engstrom says. “When this happens and you have laser and GPS systems worth hundreds of thousands of dollars mounted on a golf course at night, reactions speed up quickly.”
The total time required to survey the 18 greens was approximately five days. In the end, the survey team set a total of about 75 targets for the airborne LiDAR and terrestrial HD LiDAR surveys.
Course CorrectionsOnce all the greens were surveyed and fixed with ground control points and scanned with the terrestrial LiDAR scanner, the aerial imaging team began its flyover. HJW GeoSpatial Inc. (Oakland, Calif.) used the Microsoft UltraCam to capture high-resolution airborne digital imagery to a spatial pixel resolution of 2.5 centimeters over the entire golf course. HJW also provided an airborne GPS/intertial measurement unit (IMU) solution to assist in subsequent geoprocessing of the imagery. With this technology, IMU sensors were used to establish the three orientation angles of the camera platform. These three angles described the rotation of the camera station with respect to the ground coordinate system. IMU data filled the gap and strengthened the geometry of the aerial triangulation for any areas where ground control was not available.
After all the data from the air and the ground were collected, Terra Imaging used Leica Cyclone II TOPO to pull it all together to create a highly accurate 3D terrain and imagery topographic model of the golf course. Presented by IBM on the USGA’s Web site, the highly detailed aerial and 3D views of Torrey Pines put millions of viewers on the course with realistic, highly accurate course maps that tracked the flight of Tiger Woods’ explosive 350-yard drive or followed other challenging, seemingly impossible shots by one of the other top-ranked golfers from around the world.
According to Pete Bevacqua, chief business officer for the USGA, such tools are making the game more accessible to new players. “All the data that’s at your fingertips really allows you to become more of an expert in your own game,” he said in a podcast addressing the future role of technology in golf.1 Such tools are also crucial to attracting the next generation of golfers, many of whom are learning the fundamentals of the game on Wii and other electronic gaming systems.
As for the USGA’s role, “We use technology to control technology,” he notes. “Our fundamental purpose in the equipment world is to make sure that skill is always the ultimate factor in golf.”