Using a 3D laser scanner for the first time in a cave, a team of explorers has mapped a system of underground chambers in Southern China, the National Geographic reports in its July issue. The area is home to some of the biggest formations of its kind in the world.
The device used by the team—a Riegl VZ-400 V-Line 3D Terrestrial Laser Scanner—uses "light echo" from an infrared laser beam, which it fires in various directions whilst spinning 360 degrees. This way, the system can make extremely precise measurements of the surrounding area of up to 2,000 feet in radius.
Every second, the device makes 122,000 measurements that it later sends to a processing device, creating a model of the cavity that it is placed in, which National Geographic describes as similar to a Google Earth map. According to members of the research team, the device that was designed for use in architecture, engineering and mining, is now for the first time being used to map underground caves.
One of the chambers mapped by the team was the Hong Meigui, the size of which is estimated to span across 516,667 square feet—roughly the equivalent of nine football fields. It ranks as the eighth biggest cave chamber in all of the world. One of the key goals of the 3D laser research into caves, is to create a ranking of the world's biggest cave chambers not by territory, but by volume.
Speaking to National Geographic in a video interview, geography professor at the University of Bristol and member of the expedition team Peter Smart, praised the scanning method for providing a way for scientists to map caves that they would otherwise need extremely large lights to see in.