Josiah Lau, Novlum Inc., Canada, outlines how 3D laser scanning works, and explains why the right software can significantly improve workflow efficiency.
L
ight Detection and Ranging (LiDAR), more commonly known as 3D laser scanning, has been around since the 1960s. Today, 3D laser scanners come in many forms and are used in applications ranging from large area 3D aerial surveys to collision detection on autonomous vehicles. Within the last several years, the use of 3D laser scanning to assess structural integrity and capacity of aboveground storage tanks has gained popularity. While 3D laser scanners can capture vivid 3D images of these large, tall, and internally dark structures in a short amount of time, the software required to transform the 3D data into useful information is lacking. This is the main reason that 3D tank inspection has not become the mainstream tank inspection method even though the information gleaned from this
technology is extensive when compared to traditional inspection methods.
Scanning In order to understand the software required to process laser scanning data, also known as point clouds, it is important to first understand how 3D laser scanning works. At a high level, 3D laser scanners send out laser pulses that are reflected back to the scanner when they hit objects. The measured distance is equal to half the round trip flight time multiplied by the speed of light (Figure 1). The accuracy of each measurement depends on the ability of the scanner to resolve the peak intensity of the reflected laser pulse, which is affected by how energy 17 Autumn 2021
