What is LiDAR and how does it work?

LiDAR sensors are an essential component in GeoSLAM’s mobile mapping solutions. Together with our SLAM algorithm, these two technologies are responsible for producing 3D pictures or “point clouds” of the environment.

LiDAR technology has been around since the 1960’s when laser scanners were mounted to planes. This type of airborne LiDAR emitted light beams towards the surface of the ground to provide distance measurements. LiDAR data became a useful tool for providing accurate geospatial measurements in the late 1980s. The introduction of commercially viable GPS systems made this possible.

What is LiDAR?

LiDAR is a remote sensing technology. LiDAR technology uses the pulse from a laser to collect measurements. These are used to create 3D models and maps of objects and environments. 

What does LiDAR stand for?

LiDAR is an acronym of Light Detection and Ranging. It is also known as laser scanning or 3D scanning. 

How does Light Detection and Ranging (LiDAR) work?

A LiDAR system calculates how long it takes for beams of light to hit an object or surface and reflect back to the laser scanner. The distance is then calculated using the velocity of light*. These are known as ‘Time of Flight’ measurements. 

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

How do LiDAR sensors work?

Depending on the sensor used, LiDAR scanning units can fire hundreds of thousands of pulses per second. These light waves bounce off objects and return to the LiDAR sensor. The sensor uses the time it takes for each pulse to return to calculate distance (time of flight). Each of these pulsed laser measurements, or returns, can be processed into a 3D visualization known as a ‘point cloud’. That’s how a LiDAR sensor works explained in a nutshell. 

What is the difference between Radar and LiDAR?

LiDAR works in a similar way to Radar and Sonar yet uses light waves from a laser, instead of radio or sound waves.

What is LiDAR Technology?

LiDAR technology is the application of the remote sensing method described above. It is usually used to examine the surface of the earth, assess information about the ground surface, create a digital twin of an object or detail a range of geospatial information. LiDAR systems harness this technology, using LiDAR data to map three-dimensional models and digital elevation. From handheld to airborne LiDAR, there’s a LiDAR system to capture the data you need. LiDAR mapping uses a laser scanning system with an integrated Inertial Measurement Unit (IMU) and GNSS receiver or in GeoSLAM’s case, the SLAM algorithm, which allows each measurement, or points 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. 

What can you use LiDAR systems and LiDAR data for?

There aren’t many applications that wouldn’t benefit from using LiDAR. From the games industry to Formula 1 teams – simulations based on 3D models are often used to give teams the edge before setting foot on a racetrack. 

  • Mapping: Surveying tasks often require LiDAR systems to collect three-dimensional measurements. They can create digital terrain (DTM) and digital elevation models (DEMs) of specific landscapes. 
  • Architecture: Laser scanning systems are popular for surveying the built environment too. This covers buildings, road networks, and railways.
  • Real Estate: Laser scanners can be used indoors to measure space and create accurate floorplans. 
  • Construction: The construction industry is also using LiDAR surveys increasingly. LiDAR technology tracks building projects and produces digital twins for BIM applications. It can also help produce 3D models for the conditional monitoring of structures, and revit models for architects and structural engineers. 
  • The Environment: Environmental applications for LiDAR are plentiful. Laser scanning is a popular method of mapping flood risk, carbon stocks in forestry, and monitoring coastal erosion. 
  • Automotive: LiDAR is also seeing increased levels of adoption for automation applications. Smaller, low-range LiDAR scanners help navigate autonomous vehicles. 
  • Space Travel: If that wasn’t enough, LiDAR data isn’t only useful on earth! It has been identified by NASA as key in enabling them to land lunar vehicles safely. 

What is LiDAR mapping?

LiDAR mapping uses a laser scanning system with an integrated Inertial Measurement Unit (IMU) and GNSS receiver. In GeoSLAM’s case, we use the SLAM algorithm to power our laser mapping technology. This 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 give absolute and relative positional accuracy. This allows viewers of the data to know where in the world the data was collected and how each point relates to objects in terms of distance. 

LiDAR point cloud data can map entire cities.  Decision-makers can 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 highlight changes and abnormalities such as surface degradation, slope changes and vegetation growth.

What are digital elevation models (DEMs)?

A digital elevation model (DEM) is a three dimensional representation of terrain and all the objects within that space. Regularly spaced elevation values collected from LiDAR scans create a coordinate system that allows the earth to be reflected and modelled with a high level of accuracy. 

What are digital terrain models (DTMs)?

Digital terrain models are just like DEMs, without the objects included. They use LiDAR to map the terrain only.

LiDAR Scanning Technology Explained

So, what is LiDAR? Hopefully, we’ve satisfied your curiosity about LiDAR (light detection and ranging). This pulsed laser technology has so many applications for mapping, providing detailed information and data on the environment. What’s more, you can be assured of speed and accuracy when you carry out a LiDAR scan. 

If you’re looking for a LiDAR scanner for a business application, GeoSLAM technology gives you the power to collect the geospatial data you need. Our range of handheld laser scanners uses LiDAR and SLAM technology to produce point clouds for many different applications. Contact us for more information, and find out what a new GeoSLAM LiDAR laser scanner could do for you.