LiDAR has various applications in surveying, sensors, drones and laser scanning. So people are fairly acquainted with this technology, which is among the major emerging technologies driving the age of automation.
But there are many different types of LiDARs based on their functionality and inherent characteristics. Let’s have a look at the classification of LiDARs and how different types of LiDARs have different uses.
Based on functionality
As the name suggests, Airborne LiDARs are mounted on top of a helicopter or drone. The light is first emitted towards the ground and then it moves towards the sensor. Airborne LiDAR is further classified into topographic and bathymetric.
It is used mainly in monitoring and mapping topography of a region. So it has its applications in geomorphology, urban planning, landscape ecology, coastal engineering, survey assessment etc.
Bathymetric LiDARs are used in measuring the depth of water bodies. In a bathymetric LiDAR survey, the infrared light is reflected back to the aircraft from the land and water surface, while the additional green laser travels through the water column. Bathymetric information is crucial near coastlines, in harbors, and near shores and banks. Bathymetric information is also used to locate objects on the ocean floor.
Terrestrial LIDAR can be installed either on a tripod or on a moving vehicle. It collects data points that help in the highly-accurate identification of data. This has its application in surveying and creating 3D Modeling. Terrestrial LiDAR can be either Mobile or Static
Mobile: It is mostly used to analyze infrastructure and observe roads. Mobile LiDAR systems mostly include sensors, camera and GPS.
Static: Static LiDAR is more portable, handy to use. It collects cloud points from a fixed location and is used in mining and archaeology.
Based on other classifications
DIAL is an acronym of Differential Absorption LiDAR sensing of ozone. It is mostly used to measure Ozone in the lower atmosphere.
Wind LiDAR: Wind LIDAR is used to measure wind speed and direction with high accuracy Wind data has been conventionally gathered with great difficulty due to multiple measurement points leading to inaccuracies. Using LiDAR one can measure wind speed, direction as well as turbulence
The potential of LiDAR extends beyond the earth as well. Premier space agencies including NASA are using LiDAR in detection and tracking.
The NASA airborne High Spectral Resolution LiDAR (HSRL) is used to characterize clouds and small particles in the atmosphere, called aerosols. From an airborne platform, the HSRL scientist team analyzes aerosol size, composition, distribution and movement.
The HSRL instrument is an innovative technology that is similar to radar; however, in the case of LiDAR, radio waves are replaced with laser light.
The HSRL technique utilizes spectral distribution of the LiDAR return signal to discriminate aerosol and molecular signals and thereby measure aerosol extinction and backscatter independently.