LiDAR: What is it?

LiDAR, or Light Detection and Ranging, is a remote sensing technology that uses laser light to measure distance, shape and orientation of objects.  Where the more familiar RADAR uses radio waves to measure distance, LiDAR uses light waves. LidDAR can be used to create highly accurate 3D maps of the environment and it is changing the landscape of interior mapping.

The fundamental components and principles of LiDAR include:

• Laser Source: LiDAR systems use a laser source to emit pulses of laser light. The laser emits short bursts of light at a high frequency.

• Scanner or Mirror: A scanner or rotating mirror is used to direct the laser pulses across the target area. This scanning motion enables the LiDAR system to capture a complete 360-degree view.

• Beam Splitter: The beam splitter divides the laser beam into multiple pulses. This allows LiDAR systems to cover a larger area and capture more data points.

• Receiver: The LiDAR system is equipped with a receiver to detect the laser pulses reflected back from the surfaces in the environment.

• Time-of-Flight Measurement: LiDAR calculates distances by measuring the time it takes for the emitted laser pulses to travel to the target and back. The formula is Distance = (Speed of Light × Time) / 2.

• GPS Receiver: Many LiDAR systems are integrated with GPS receivers to provide accurate geospatial positioning information for each data point.

• Inertial Measurement Unit (IMU): An IMU is often included to measure the LiDAR system's orientation and motion. This information helps in accurately georeferencing the collected data.

• Data Processing Unit: LiDAR systems generate massive amounts of point cloud data. A data processing unit is essential to organize, filter, and analyze the data, converting it into a usable format for applications like mapping or 3D modeling.

• Power Supply: LiDAR systems require a power supply, which can vary based on the technology used (airborne, terrestrial, or mobile LiDAR).

• Wavelengths: LiDAR systems can use different wavelengths of laser light. While many LiDAR systems use near-infrared wavelengths, others may use green or other wavelengths depending on the application.