The terrorist attacks of Sept. 11 woke up many agencies to the importance of documenting our nation’s critical infrastructure, monuments and historic buildings with high-definition 3D laser scanners.
The National Park Service, for example, has completed a number of mapping projects, including Mount Rushmore. The Statue of Liberty has been mapped both pre- and post-9/11. Immediately after the terrorist attacks, I had the privilege of assisting a Leica Geosystems’ client in the scanning of the U.S. Capitol building. This important scan data now enables officials to monitor, maintain and, in the case of catastrophic loss, precisely reconstruct these structures.
Lines Versus Points
Whether reacting to a terrorist event or a natural disaster, emergency responders need to first get an idea of what they’re dealing with. Historically, they’ve had to rely upon architectural or engineering drawings, blueprints, etc., if available. But today’s high-definition 3D laser scan data offers a better option.
Laser scan data is dimensionally and spatially accurate, and it’s 3D where a blueprint is just a 2D line drawing. With the point cloud data, I’m looking at the entire structure in three dimensions, not just a flat piece of paper. We are 3D mechanisms. We see and interact in 3D. It only makes sense to capture structures in 3D for us to refer to later on.
With Leica Cyclone 3D point cloud processing software or Leica’s free TruView visualization software, users can virtually walk or fly through the digital environment as well as quickly extract highly accurate measurements, angles, etc., on-the-fly. Scan data can also be available at a moment’s notice and backed up in multiple locations. Oftentimes, with drawings, no one has any idea where they are or who’s holding onto them.
Even if emergency responders have immediate access to 2D drawings, they may not be accurate. When buildings are constructed, they’re rarely built the way the architect or the engineer wanted them to be built. Designs are often altered on site. A contractor may say, “Hey look, I know the architect wanted a shear wall, but that just isn’t going to work. We’re going to have to put a doorway there.”
When buildings deviate from their original designs, the new information is sometimes passed back to the architect so the drawings can be updated. But most of the time, that doesn’t happen. You could have a set of drawings that you believe are current, but they really aren’t. They’re revision five when, today, we are on revision 20.
I experienced this firsthand. When I arrived at the Pentagon after 9/11 to laser scan the damage, a huge trailer was set up on site. Inside the trailer were several computers and printers, and those printers were plotting out the Pentagon’s as-built drawings, which, it was discovered, were not accurate. They were using those to walk around and say, “Hey, there should have been a wall here.”
Life or Death
Too often, the lack of actionable laser scan data could mean the difference between death or life.
This was the case following the 2008 terrorist attacks on the Taj Mahal Palace hotel and tower in Mumbai, India. It was an eye-opening experience because the country’s police and security forces were able to reflect and say, “Hey, wait a minute. We did have blueprints, but those blueprints were very old, and they said that there was a doorway that led to a corridor, and that was actually sealed off into a closet now.” In a post-brief, responders said they wished they’d had some way to know what the layout looked like—at that moment in time—before they went into the building because they would have had a better idea of the locations of the bad guys, many of whom got away.
A similar situation happened during the 2004 Beslan massacre in Russian. The security forces that stormed the building had no idea what the layout of the school was. The three-day siege involving more than 1,100 hostages—777 of which were children—ended with 385 people dead.
Today, a single person can scan the interior and exterior of a building, even a multistory building, very fast, especially if it’s done with the 1-million points per second Leica ScanStation PS40 set on a rolling base.
In addition, with the 2014 launch of Leica Cyclone 9.0 3D point cloud processing software, there is no longer any need to set targets for registration. This speeds the scanning process even more. Back in the office, Cyclone’s new Automatic Initial Alignment tool unites the majority of the scans upon upload of the data. Any remaining scans that need manual assistance can be done with Cyclone’s new, easy and intuitive Visual Alignment tool, which is about 40 percent faster than the previous cloud-to-cloud routine.
Whether a result of natural disaster, terrorism or catastrophic failure, it’s important to have our critical infrastructure, national monuments, and historic buildings mapped prior to an event so that if something happens, God forbid, we can go back and say, “This is what it looked like before. We can now rebuild or repair it.”
——————————— About the Author: Frank J. Hahnel III has been laser scanning since 2000 and is an expert in the use of Leica 3D laser scanning systems. He has worked with multiple state and local law enforcement agencies and private accident investigation and reconstruction firms, helping them to scan, to process and to reconstruct active accident and crime scenes. After the September 11th terrorist attacks, he aided the Army Corps of Engineers at Ground Zero in New York and the FBI at the Pentagon. He then assisted the NYPD and FBI with the laser scanning of the debris piles from Ground Zero at the Fresh Kills Landfill, the story of which was published in Professional Surveyor Magazine in 2011. He is a member of the International Association for Identification, International Association for Counterterrorism & Security Professionals, the International Association of Chiefs of Police, and the National Association of Professional Accident Reconstruction Specialists, Inc.