Event Report: Leica Geosystems High Definition Surveying Conference29 Oct, 2008
HDS practitioners trade tips and tricks.
The presentations and conversations overheard at Leica Geosystems HDS and Airborne Sensor Worldwide User Conference this week indicated high-definition surveying (HDS) is dramatically reshaping the function of the surveyors. Now, equipped with a portable device that lets them capture a highway intersection or an archeological site as a 3D scene in point clouds with unprecedented speed and accuracy, surveyors have become the custodians of a vast amount of as-built data, a new role that offers both optimism and uneasiness. Along with business opportunities come new questions: How do you market the new deliverables to your clients? How do you repackage the deliverables to offer the best value to your clients? In what types of projects does HDS offer the most benefit?
On Monday, October 27, enthusiasts, practitioners, and beneficiaries of the technology streamed into the Marriott Hotel in San Ramon, California, to trade business cards, share tips, and recount war stories.
A New Kind of Surveying
Survey equipment maker Leica's HDS product family, which was on display outside the conference room last week, includes the Leica ScanStation 2 and Leica HDS6000. ScanStation 2 is described as a machine with an integrated high-resolution camera, a patented microchip-driven laser that delivers accurate distance measurement, and a dual-axis level compensator for traversing and stakeout jobs. It reportedly can operate "up to 10 times faster than other pulsed scanners."
The HDS6000 is described as the next-generation, phase-based laser scanner, capable of processing laser returns up to 79 meters and detecting laser returns from dark and oblique surfaces. It is designed to deliver higher accuracy, scan density, and longer ambiguity interval with less noise.
Leica Geosystems HDS6000, one of the high-definition surveying machines on display at Leica Geosystems HDS Conference.
Leica also supplies a collection of software for processing the point-cloud data acquired by the scanner. The Cyclone software modules let HDS system users manage the scanning process, register (or georeference) the point clouds, transform the point clouds into CAD-compatible geometric objects, and extract coordinates from the point clouds. Cyclone is complemented by the CloudWorx software series, which allows users to work with the point clouds directly from their preferred CAD environment, such as AutoCAD, MicroStation, or AVEVA's PDMS (for plant design).
In his presentation, Gus Rios, an associate surveyor from the surveying firm Diamond West, recalled how HDS came to the rescue of REthink, an environment-conscious real-estate development and consulting firm.
While presenting his project to the residents of a community, a REthink representative endured a barrage of questions: Will your four-story project tower over our two-story homes? Will it block the view of the nearby hills?
"He looked a bit shaken," recalled Rios, who witnessed the meeting. "So I gave him a couple of days, then contacted him to tell him we have this technology." As soon as the HDS demonstration was over, Diamond West was hired to scan the site of the project.
Rios and his team then captured the site in point clouds, imported the data into NavisWorks JetStream, and then placed the 3D SketchUp architectural model into the scene. Armed with a panoramic view that could be inspected from any angle, REthink was able to address the residents' concerns in a subsequent meeting.
Rios read the testimonial quote REthink sent to him afterwards. "The community members, who are often skeptical of an architect's rendering, have been very accepting of the scanner images," it read.
Across the Atlantic from California-based Diamond West, Conor Graham from Gridpoint Solutions in Belfast, Northern Ireland, came to the rescue of Nenagh Castle, a Norman architectural specimen dating back to the 12th Century.
"Believe it or not," Graham said, "we were the first to offer HDS services in Northern Ireland. … More recently, we've gone into heritage applications, or preserving historical and archeological sites."
A rendering based on the point-cloud data acquired by an HDS system serves as the 3D record of a Kells cottage's structure (above). When converted to an AutoCAD file, the drawing serves as a 2D elevation view of the same structure (below) (images courtesy of Gridpont Solutions).
Nenagh Castle, built long before the emergence of CAD, was never recorded digitally, nor on paper, for that matter. Over the years, vegetation began to encroach on the castle walls. The stonework on the tar also showed visible signs of deformation. As part of its efforts to preserve its national heritage sites, through accurate records, the Republic of Ireland commissioned Gridpoint to scan the castle's exterior.
"Obviously, the target is a cylinder, but the client wanted an unwrapped elevation drawing," Graham said. Fortunately, the windows on the castle served as ideal anchor points. Using those for alignment, Graham and his team were able to produce the drawing the client wanted. The result was a 2D document of the surface of the castle, with every stone meticulously traced and marked in AutoCAD.
A cross-section taken from the unwrapped view of the Nenagh Castle's stonework, recreated in AutoCAD based on HDS scan data (image courtesy of Gridpoint Solutions).
The conference continued on Tuesday and Wednesday, concluding with a series of hands-on workshops on Thursday that taught attendees how to set up and traverse with a scanner, model a plant environment, and register the point clouds.
For more, listen to the Webcast titled "HDS: A Leap of Faith or a Competitive Advantage During a Down Economy?" (originally broadcasted October 2, 2008).
AEC, Civil Engineering, GIS (Geographic Information Systems)