LiDAR technology has been around since the 1960's when laser scanners were mounted to planes. It wasn't until the late 1980's, with the introduction of commercially viable GPS systems, that LiDAR data became a useful tool for providing accurate geospatial measurements. Here we take you through the basics of LiDAR - what is it, how does it work and what can it be used for?

LiDAR is a remote sensing technology which uses the pulse from a laser to collect measurements which can then be used to create 3D models and maps of objects and environments.
LiDAR is an acronym of Light Detection and Ranging
LiDAR works in a similar way to Radar and Sonar yet uses light waves from a laser, instead of radio or sound waves. A LiDAR system calculates how long it takes for the light to hit an object or surface and reflect back to the scanner. The distance is then calculated using the velocity of light*. These are known as ‘Time of Flight’ measurements.

LiDAR systems can fire around 1,000,000 pulses per second. Each of these measurements, or returns, can then be processed into a 3D visualization known as a ‘point cloud’.

*The velocity, or speed of light is 299,792,458 metres per second

LiDAR systems are most commonly used for surveying tasks. Because of their ability to collect three dimensional measurements, laser scanning systems are popular for surveying the built environment (such as buildings, road networks and railways) as well as creating digital terrain (DTM) and elevation models (DEMs) of specific landscapes.

Environmental applications also benefit from LiDAR – laser scanning is a popular method of mapping flood risk, carbon stocks in forestry and monitoring coastal erosion.

LiDAR is also seeing increased levels of adoption for automation applications. Many automotive manufacturers are using smaller, lower range LiDAR scanners to help navigate autonomous vehicles.

What is LiDAR Mapping?

LiDAR mapping uses a laser scanning system with an integrated Inertial Measurement Unit (IMU) and GNSS receiver which allows each measurement, or point in the resulting point cloud, to be georeferenced. Each ‘point’ combines to create a 3D representation of the target object or area.

LiDAR maps can be used to give positional accuracy – both absolute and relative, to allow viewers of the data to know where in the world the data was collected and how each point relates to objects terms of distance.

LiDAR data, in the form or a point cloud, can be used to map entire cities, enabling decision makers to accurately pinpoint structures or areas of interest in millimetre perfect detail. Features and objects such as road networks, bridges, street furniture and vegetation can be classified and extracted.

LiDAR maps can also be used to highlight changes and abnormalities such as surface degradation, slope changes and vegetation growth.