Geo-Referenced, UAV-based 3D Surveying System for Precision Construction

Significant project cost and schedule advantages can be achieved by effectively managing and maintaining configuration management CM) of plant data beginning in the design and construction phases of a nuclear plant, such as through the use of 3D scanning technology. In, fact, the United States General Service Administrations Office of the Chief Architect OCA) has commanded that every federal facility project should be documented in threedimensional 3D) coordinates using laser scanning technology for acquiring building spatial data. However, the implementation of 3D data for accurate asbuilt creation is still challenging, especially for openings and fine details of the construction objects in an indoor environment. Also, systems are large, expensive, and lack the fine resolution required of the application, and they often are not adequately calibrated, rectified, and georegistered. As such, current practices still needs to be improved for asbuilt documentation purposes. To address the need for highresolution, smallsized LIDAR instrumentation and data management, a robust, miniature, mobile dualmode laser scanner LIDAR) instrument will be developed that overlays 3D scanning data on visible imagery for processing and comparing as built configurations against designs. The innovative LIDAR scanners make available technology that was previously unavailable. Operating at eyesafe wavelengths, these small size, weight, and power SWAP) configurations are designed for easy reconfiguration for use as mobile handheld, mobile, or UAVmounted devices. The technology integrates previously unavailable highrate eyesafe laser technology with singlephotonsensitive avalanche photodiode APD) receiver technology, to allow highly accurate, longrange LIDAR imaging in a very compact package. Combined, these technologies extend the range of current laser scanners from their current state of 30 m to a capability exceeding 2 km, while also offering improved accuracy1 mm, in a sodacansized package, at a cost of about $5,000. After working with DOE and other stakeholders to refine requirements, a trade study will be conducted, and the design will be developed of the compact eyesafe LIDAR, which will be easily integrated in mobile, handheld, tripod, or smallsized unmanned airborne system SUAS) platforms. A breadboard demonstrationincluding an ultraminiature highpulserepetitionrate eyesafe i.e., 1540nm) laser, a highly sensitive APD receiver integrating a custom pulse detection and processing applicationspecific integrated circuit ASIC), a compact microelectromechanical systems MEMS) scanner, a precise GPS/IMU, and a reconfigurable processing corewill be performed before a Preliminary Design Review PDR) is conducted in preparation for a Phase II program in which the system will be productized and integrated with building information management BIM) systems. Recent studies by the Construction Industry Institute have indicated that, for a typical $100 million construction project, between $500,000 and $1 million is spent keeping track of where things are on site and monitoring the status of construction activity. This indicates that the timely knowledge of project statuswhere things are, what has been done, what needs to be doneis the single most important issue facing construction managers today. Realtime assessment and documentation in terms of 3D asbuilt models of constructionssuch as the asis condition of a hazardous environment where human intervention would be impossiblecould save the U.S. economy billions of dollars annually. The system can also be used for flood risk management, oil and gas exploration surveys, real estate development, power line transmission or pipeline corridor planning, coastal zone mapping, forestry, and urban modeling, wetlands, and other restrictedaccess areas.