November 24, 2010 By John Stenmark
Photo: The GIS Team at the Langley Research Center was tasked with scanning and photographiong some 30,000 square feet of the facility — including 2.7 miles of utility tunnels. Photo courtesy of NASA.
In 1917, President Woodrow Wilson signed an order to establish a laboratory dedicated to aeronautical research. As a result of that order, NASA’s Langley Research Center (LaRC) was established in Hampton, Va., to help America keep pace with rapid European advances in aircraft and flight technology. Today, Langley is America’s oldest civilian facility dedicated to aeronautical and aerospace research. With more than 290 buildings on 788 acres, LaRC is home to wind tunnels, test structures and laboratories that conduct research on military and civilian aircraft and spacecraft.
Langley is respected as a premier location for U.S. aerospace research and testing. Its achievements include research that first enabled aircraft to fly at supersonic speeds and development of methods for orbital rendezvous and docking. Langley served as the initial home for Project Mercury, America’s first manned spaceflight program, and had the lead role in the Mars Viking Lander program. A key facility in development of the space shuttle orbiter, LaRC has participated in testing and development of virtually every type of aircraft flown by the U.S. military.
Because of LaRC’s size and variety of functions, its facilities must constantly evolve. To support the changing needs of operations and facilities management, LaRC’s Center Operations Directorate (COD) needs up-to-date spatial information on its buildings and equipment. Much of this information is developed and managed in COD’s GIS. To manage the system, the LaRC’s GIS team evolved. The team is a group of GIS professionals, surveyors and engineers that provides positioning and spatial data services to the research center’s facilities managers and contractors. The research center’s size and varied needs has led the GIS team to develop new ways to collect and share spatial information. To gather data, the team uses a variety of high-accuracy positioning technologies including GPS, 3-D scanning and optical total stations. According to GIS Team Lead Brad Ball, the group’s passion for technology has given LaRC the reputation as the most advanced GIS of any NASA center.
The foundation for the center’s GIS is a geodetic coordinate system and series of fixed markers on the Langley base. When collecting data, surveyors and GIS operators use these markers to make sure that their measurements and position data fit together accurately. GPS is one of the primary methods for capturing positions, and the LaRC GIS team uses high-accuracy real-time kinematic (RTK) methods to measure positions accurate to a few centimeters. To provide the basis for this work, the GIS team installed a Trimble NetR5 GPS Reference Station on their building. Known as a continuously operating reference station (CORS), this local reference station serves as the basis for all GPS surveying and GIS positions on the base. It broadcasts information needed for RTK work and collects data for post-processed analyses. The CORS data is available to GIS operators and surveyors in the surrounding communities as well.
Photo: An engineer at the Langley Research Center uses a 3-D scanner to map a part of the facility's interior. Photo courtesy of NASA.
All of Langley’s roads, utilities, buildings and structures are tied to the LaRC GIS and coordinate system, which extends to the base boundaries and surrounding areas. When a new item is added to the GIS, the geodetic framework can be used to precisely determine the object’s physical relationship to its surrounding features.
An example of this integration is the use of building information models for facilities design and management in one of LaRC’s older buildings. Over the years, LaRC Building 1230 has undergone numerous modifications. Building drawings haven’t always kept pace with the changes, and engineers and construction teams often worked with outdated or incomplete information when operating and updating the facility. In preparation for a recent remodel, interior walls were removed from one wing of the building. With the structural and mechanical features exposed, the GIS team scanned the interior and exterior of the building. The scanner produced a point cloud consisting of millions of individual 3-D points that depicted the building; each point was accurate to a few millimeters.
For the work at Building 1230, the team used RTK to establish exterior setup points for the scanner. Using the CORS as a reference, the GPS points could be tied directly into the LaRC’s geodetic coordinate system. “We scanned the interior and exterior of the building from 15 different locations and composited the scans together,” said Jason Hall, a GIS analyst on the Langley team. “We linked the interior scans by carrying control through stairwells. We used the GPS points for the exterior scans, and connected them to the interior by sighting through window openings.”
The crew used the 3-D scanner’s video camera to capture photographic images of the scene. The images can be draped over the point cloud to produce a 3-D photorealistic image of the building, right down to individual bricks, bolts and fittings. In less than a week — and while continuing support to other projects — the team had developed a true-color, high-density point cloud of the wing’s approximately 30,000 square feet.
With the fieldwork complete, the LaRC team processed and checked the data. Then they extracted subsets and cross-sections that were sent to Autodesk Revit and other computer-aided design (CAD) systems for use in developing design and construction plans. In just a short time, scanner technology has become an important part of LaRC’s GIS and facilities management toolbox. Langley will be increasingly using building information modeling for its facilities development and management, and Ball said that the 3-D scanner plays an important role in validating the building models.
Just below the surface at NASA’s Langley facility, a series of tunnels contains steam lines, water pipes, electrical equipment and other utilities. LaRC’s utility systems have been repeatedly modified and upgraded, and recent studies of the steam system exposed some serious problems. The requirements for the legacy steam system have continually expanded and the system was originally installed without the benefit of currently available technology. As a result, there were numerous low points in the steam lines that produced water buildup and hammering. To address the problem, the GIS team needed to measure and catalog the steam lines to find all the low points. With that information, crews could install condensate drains to eliminate the water.
The work covered four tunnels with a combined length of nearly 2.7 miles. In addition to collecting horizontal and vertical locations of the steam lines and fixtures, the GIS team captured the location of all valves, pumps and other items that carried maintenance identification tags. “The water and high-pressure air systems are in the steam tunnels,” Ball said, “and some of these utility tunnel features haven’t been viewed for 50 years. This was an opportunity to collect accurate locations on all of this structure and equipment.”
Hall and his colleague, Dana Torres, worked in cramped spaces jammed with pipes, conduits and machinery. The team combined RTK with optical measurements to connect the tunnels to the GIS. Their work was hampered by the presence of maintenance and construction crews working on the various utility and communications systems. Hall and Torres used a global navigation satellite system for the RTK work, and another station for the optical portions. They collected positions and GIS attribute information on nearly 3,200 features, and maintained critical vertical accuracies of 0.04 feet. The information was loaded into geomatics software for quality checking, and then output to Esri ArcGIS and other software for graphical and numerical analysis. In addition to capturing locations for the utilities, the work corrected some old errors. “Jason and Dana thoroughly measured the sides and the corners of the tunnels,” Ball said. “They found parts of this massive tunnel system that were four feet off compared to earlier maps.”
For most GIS work, the GIS team uses the CORS in conjunction with the Trimble R8 GNSS RTK System to obtain centimeter accuracy. On a recent project to validate existing utility location data of the base, the team used RTK to measure roughly 1,000 points on the base. They compared the measured positions with legacy CAD data. The work revealed enough inaccuracy to justify creating new high-resolution aerial images of the base. To provide control for the new images, the team measured the positions of dozens of monuments and valve covers visible in the new images. Many of the valves were located close to buildings and couldn’t be measured using GPS. For these points, the team used integrated surveying techniques to combine RTK data with measurements taken with a high-performance surveying station. The result was a two-inch resolution image with accuracy needed to support utility corrections.
The GIS team uses 3-D scanning technology to support scientific research as well as facilities management. As part of a proposed new test, NASA researchers wanted to evaluate use of overhead crane rails in a wind tunnel to suspend test apparatus. For the test apparatus to function properly, the project engineers needed precise information about the relationship between the crane rails, and the bottom and throat of the tunnel. The GIS team scanned the wind tunnel and collected roughly 3 million points in less than one day. The point cloud was exported to Drawing Exchange Format and AutoCAD formats, and the researchers used the information to determine dimensions in the wind tunnel to a precision of 3 mm.
As part of its role in facilities management, the LaRC team uses georeferenced spatial information for space optimization and allocation planning. They developed a GIS-based approach to Space Utilization Optimization with the objective of minimizing operational costs while maximizing synergy between functional centers. The GIS team is developing facility consolidation plans that offer projected benefits valued in the range of hundreds of thousands of dollars.
The Langley GIS team’s accomplishments haven’t gone unnoticed. As part of NASA’s process of implementing new systems and methods, the Langley GIS team frequently travels to share their expertise with other NASA and federal facilities. In 2009, the team received a Special Achievement in GIS award from Esri in recognition of the team’s innovation and leadership in GIS and spatial data.
Through its use of scanning technology, the NASA Langley GIS Team has developed the reputation of measuring objects and facilities that otherwise would be very difficult to measure. “With this equipment, we deliver information that no one else can provide,” said John Meyer, an engineer on the GIS team. “The fact that we can supply accurate measurements to a variety of disciplines is very important.” The technology has demonstrated that it delivers significant time and cost savings on maintenance and remodel projects, and Ball believes that 3-D scanning and high-accuracy GIS are rapidly becoming standard tools for facilities management. According to Ball, it’s simply good business. “It’s important to let creative people pursue new ways to do things,” he said. “Some people are wary of investing in the new technology. But it’s not all that risky once you turn it loose.”
John Stenmark, LS, is a writer and consultant working in the architecture/engineering/construction and technical industries. He has more than 20 years’ experience in applying advanced technology to surveying and related disciplines.
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