Utilizing Lidar data in the GIS environment serves as a go-to technology for GIS analysts to provide accurate measurements. Which can be utilized in so many ways such as developing elevation models, mapping rooftops, assessing utility right of way, and many others.
What is Lidar data:
The Light detection and ranging (Lidar) data are deployed from either ground, spaced based, or aircrafts using sensors that utilize non-visible light, mapping the ground surface and objects present on the surface of our Earth.
Its sensors accurately measure the location and height information of various landscape targets.
Ladar data in the GIS environment
When surveying using LiDAR, thousands of points are produced, and when imported into a Geographic Information System (GIS) produces a cloud of points. Point clouds are processed, using computer algorithms, to remove all but the first and last returns.
The remaining data can then be used to create a Digital Surface Model (DSM) and Digital Terrain Model (DTM) for visualization and interpretation.
A DSM is a model of the surface of the earth, derived from the first return points, which includes all the features on it such as vegetation and buildings.
Whereas a DTM is a ‘bareearth’ model, generated from the last return points, with vegetation and buildings stripped away. A DTM is particularly useful for seeing the ground surface beneath high vegetation.
Moreso, the different types of Lidar in use vary slightly in the way they process and acquired data. And taking notes of these various Lidar types can give you a head start on a project.
Enabling you to choose the type of Lidar to incorporate for the application.
What are the types of Lidar data?
- Airborne LiDAR
With airborne LiDAR, systems are mounted on aircraft platforms like a helicopter or drone. Light pulses are emitted from the aircraft to the ground, to measure and scan the distances and dimensions of what lies below.
- Terrestrial LiDAR
Terrestrial LiDAR, systems aren’t mounted on an aircraft. However, it is mounted on a vehicle in motion or a tripod on the ground. Terrestrial LiDAR systems often scan in several directions with the use of mirrors. This allows them to capture data from all around in form of a 3D photo
How does Light Detection and Ranging (LiDAR) work?
Light Detection and Ranging (LiDAR) is a technology similar to radar, using a laser instead of radio waves.
LiDAR principle is pretty easy to understand:
- it emits a laser pulse on a surface
- catches the reflected laser back to the LiDAR pulse source with sensors
- The time of flight traveled by laser is measured
- calculates the distance from the velocity of light formula “Distance = (Speed of light x Time elapsed) / 2
This process is repeated a million times by LiDAR instruments and ends up producing a complex map of the surveyed area known as a 3D point cloud (systems referred to as multiecho).
Modern applications of LiDAR data:
- For tracking changes in the atmosphere.
- Land Mapping
- Oil and Gas Exploration
- Management of Parks and Tourist industry
- Renewable Energy
- Tsunami Modelling.
Keep in touch to know how well you can explore your point cloud processing efforts by sending us a mail: [email protected] or view our contact icon to connect with us today.