In Tanzania, a helicopter mounted with an advanced laser sensor hovers over a tropical forest. With the data gathered, modern cartographers will generate a 3D map at a scale of 1:1000, offering over 24-times the resolution of a standard USGS 7.5-minute quadrangle. Meanwhile, thousands of miles away in the Sierra Nevada Mountains of California, researchers wear a backpack—equipped with curious LiDAR tower—and walk through giant sequoia groves to create volumetric models for studying and comparing the world’s largest trees. And in China, preservationists use mobile laser scanners to create digital representations of the Great Wall of China. These examples might seem like scenes from science fiction, but they’re actually just a few of the adventurous projects conducted by GreenValley International.
“The possibilities from [the Great Wall] scan are exciting,” says Dr. Qinghua Guo, Founder and CEO of Green Valley, International. “You can see individual bricks and even measure them with a millimeter of precision.”
In recent years, GreenValley products have been used for dozens of projects related to improving environmental management. Grassland ecosystems of the Central Valley have been modeled in 3D, allowing for a deeper understanding of how topography and morphology relate to species and soil composition. A common snowpack indicator called snow water equivalent has been measured in the high Sierras using aerial laser scanning systems, whereas traditional methods involve a few depth sensors that are used to estimate a larger region. Such projects reveal GreenValley’s hopes to pioneer the transition from traditional 2D projections to full 3D mapping.
“Our company motto is map the world in 3D,” says Dr. Guo. “We see the traditional 2D mapping and its limitations as an issue.” As an example, Dr. Guo points to forestry and its reliance upon photogrammetry, which involves extrapolating 3D data collections by examining overlapping 2D aerial photographs taken from various angles. “Photogrammetry typically doesn’t have enough [canopy] penetration, if at all,” says Dr. Guo.
By combining remote sensing data from two methods—the terrestrial-based LiBackpack and the aerial-based LiAir—GreenValley believes it has an integrated solution. “The LiBackpack is perfect for under-canopy mapping,” says Dr. Guo. “This data can be geo-referenced and registered to match scans acquired by the LiAir—which provides detailed information [height, density, and volume] on the top of canopy.”
A recent GreenValley project for Chugoku Lumber on Kyushu Island, Japan, demonstrated the potential of LiDAR-based timber growth monitoring and forest inventory. Traditional methods to determine the volume of timber available as board feet of lumber rely upon estimates from photogrammetry combined with labor-intensive ground-based surveys. These surveys involve foresters estimating the overall timber volume by measuring the diameter of each tree at breast height. Green Valley’s solution replaces forestry extrapolations from satellite and aerial imagery with more accurate 3D LiDAR data. And the intensive ground surveying is replaced by much faster terrestrial laser scanning, which provides more precise information on individual tree dimensions and, consequently, the overall timber volume of a forest.
With GreenValley’s founders possessing plenty of interdisciplinary experience—including the environmental, photogrammetry, and computer sciences—Dr. Guo envisions a variety of applications for their solutions. In the urban setting, they mapped a subway station in Nanjing, China, during April 2017. Other potential applications include mapping subterranean tunnels and complex cave systems.
But ultimately, the goal for Dr. Guo and his co-founders is to improve environmental management. The name GreenValley is an homage to the Central Valley of California, where the company began in Merced in 2013.
“Our hope is for a greener environment, not just for the valley, but for the world,” says Dr. Guo. “We can create a sustainable society through the use of technology. LiDAR 3D mapping allows us to gain better intelligence on our environment and improve techniques.”
See the GreenValley LiBackpack in action, which uses a Velodyne Puck or HDL-32E sensor: