If you’d been in Seaside Heights, Ortley Beach, Normandy Beach, and Mantoloking, New Jersey or New York’s Staten Island and Rockaway Peninsula between December 5 and December 9, 2012, you may have been surprised to see a blue van with two futuristic roof-mounted laser mapping units cruising neighborhoods ravaged by Superstorm Sandy.
At the helm of this operation was Rutgers University’s School of Engineering assistant professor Jie Gong using land-based 3-D geospatial mapping method, mobile LiDAR (light detection and ranging), to document storm damages and collect data that can be used to plot recovery from the storm. Laser light sent from the van’s roof pulses off objects and is then processed into detailed, accurate images by the van’s receivers.
Traditional damage assessment is an exacting and time-consuming process. During Thanksgiving break, Gong surveyed ravaged coastal areas with teams from Princeton University and Notre Dame University that were assessing the storm’s impact the old-fashioned way: by taking photographs and painstakingly identifying each house and structure. By later measuring the data against existing survey maps, these teams would be able to assess the level of damage caused by the storm.
Gong believes his team is the first to use 3-D geospatial mapping with mobile LiDAR to assess damage caused by Sandy. “We hope to prove that mobile LiDAR is a safer, quicker, more accurate and more cost-effective way to evaluate storm damage and survey for reconstruction,” he explains. “We believe the traditional sequential process of first assessing damage and then surveying for reconstruction can become an overlapped process due to the high-quality of the 3-D images.”
The high-resolution, three-dimensional images generated by LiDAR can be used to create a virtual reality of the flooded community, a record that can be examined in close details by coastal engineers to study wave, surge, and wind damage mechanisms. The images also can be used to generate survey quality engineering drawings that can serve as the basis for clean-up, demolition, recycling, rebuilding and recovery efforts. “If we can prove this method is quicker and better, we can develop a dynamic new way of responding to hurricane disasters and handling the recovery process,” Gong says.
The van’s work in December was just the beginning. “Right now, we are processing the data we collected in December,” he explains. By comparing his data with airborne LiDAR data collected in 2010, he will be able to provide a valuable record of the extent of the devastation wrought by Sandy – information Rutgers ultimately plans to share with government officials and city planners.
“It’s all about turnaround time,” notes Gong. “The equipment on our van collected a million data points a second. It only took us about an hour to map ten to twelve streets. This is a huge advantage, because we can collect data on up to 30 miles of shoreline in a single day, while traditional methods can take weeks or even months to cover that kind of ground.”
To date, Rutgers’ Center for Advanced Infrastructure and Transportation has funded the project. “Without the support and encouragement of CAIT director Ali Maher, Civil and Environmental Engineering department chair Nenad Gucunski and School of Engineering dean Thomas Farris, this project simply would not be possible,” says Gong, who joined the Civil and Environmental Engineering department in fall 2012. While project results could revolutionize future disaster recovery efforts, he has an immediate use for his data: students in his Building Information Modeling class will be using it to build course project models and simulations.
Gong hopes to obtain additional funding so that he can revisit the coastal areas hit hard by Sandy in the spring. “I’d like to see what the new normal is by getting a new, accurate baseline measurement of the Jersey and New York shorelines,” he says. “This would be a great help in preparing for the future.”
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