Light Detection and Ranging (LIDAR) is a technological game-changer for not only how the world is viewed, but also how we use its natural resources. Through the use of lasers, LIDAR creates precision images that feature thousands of data points. This provides a fast and efficient solution with a wide variety of applications. Here’s a comprehensive guide to LIDAR surveying.
LIDAR uses active remote sensing that emits pulses of light and waits for their return. It’s capable of emitting 160,000 pulses each second and has a point density of less than a meter. It works by scanning the ground from side to side as the plane or drone flies over the area. It can penetrate forest canopies and buildings.
The data collected is interpreted through various models. Digital Elevation Models measure the bare ground to determine slope, hillshade, and aspect. Canopy Height Models measure the exact height of topical features on the Earth’s surface. The strength of LIDAR surveying can also measure light intensity and point classifications.
Types Of LIDAR Systems
There are several types of LIDAR systems. The first system ever used was profiling LIDAR that measured single line features in the 1980s by emitting a single pulse to measure height. The system used most today is small footprint LIDAR. It scans the ground at a 20-degree angle going forward and backward. Large footprint LIDAR measures terrain using full waveforms with 20m footprint returns. Ground-based LIDAR scans buildings while placed on a tripod.
How does a LIDAR system work? There are four components that make up LIDAR detection systems. Near-infrared or green sensors scan surfaces from side to side in an aerial view. GPS receivers keep track of the variables involved in measuring terrain elevation accurately. Inertial measurement units keep track of the airplane’s tilt in order to measure the precise incident angle of the emitted pulse. Computers record all the data received from the LIDAR technology.
There are numerous applications for LIDAR services across various industries. Ecologists can use it to measure tributaries and foresters can measure the structure of trees. Self-driving cars are equipped with LIDAR detection to identify obstacles, pedestrians, and stop signs. Archaeologists are using it to uncover ancient civilizations. This technology is also being used for oil and gas exploration, transportation planning, military use, and public safety efforts to repair the one-third of roads that are in poor or mediocre condition.
LIDAR surveying is providing a valuable solution in using our natural resources efficiently and learning about the ground on which we all live. Its applications are endless. As this particular technology grows, we’ll be able to find solutions to many of the problems we face on a daily basis.