Visualizing More Than Just the Terrain: Integrating LiDAR Data in Your Application

LiDAR, which stands for Light Detection and Ranging, is an active remote sensing method that uses light in the form of a pulsed laser to measure the relative distance from the sensor to objects within line of sight. The resulting data can be used to build up a highly accurate 3D picture of terrain and objects. With the rapid advancement of lightweight LiDAR sensors that can be carried by Unmanned Aerial Vehicles, (UAVs), LiDAR data is increasingly being used to capture highly detailed environment data for mapping and other geospatial applications.

The decreasing cost of UAVs has resulted in organizations and governments worldwide creating increasingly detailed and maps of the world – some of which include LiDAR data for things like structures and trees, in addition to terrain, and these data sets are being increasingly published online.

These new data sources can be ten or a hundred times more detailed then the data available just a few years ago.

LiDAR can be used to build detailed topographical maps, or to display objects around the sensor as a cloud of points. However, a single LiDAR file can easily contain millions of points of data, and displaying that data in an interactive 3D map can be difficult; which begs the question: how can a project most effectively take advantage of this new wealth of data?

There are different approaches you can take to displaying LiDAR data, which include displaying raw data in the form of a point cloud, or “baking” that data into a Digital Terrain Model (DTM), which typical requires less in the way of real-time computing resources to display – since it is only rendering a single mesh, instead of millions of individual points.

Whether your LIDAR data is in the form of a point cloud or a digital terrain model, Kongsberg Geospatial’s TerraLens SDK can be used to display LiDAR data quickly and easily. The SDK has supported the display of Digital Terrain Models for some time, but has more recently added an API to support the display of raw point cloud data.

The new point cloud API allows the user to display millions of points with either intensity returns or RGB color data. TerraLens uses a dynamic level of detail system to make sure that your application runs smoothly while still displaying as much data as your screen can visually display.

Sourcing LiDAR Data

If you’d like to experiment with visualizing LiDAR data, there are an increasing number of online sources for free public domain LiDAR terrain data. These include the following:

• The United States Geological Survey (USGS) (enter “LiDAR” in the data sets search tab)
• The National Oceanic and Atmospheric Administration (NOAA)
• Department for Environment Food & Rural Affairs (United Kingdom)
• Open Topography

The data used in the illustration above was derived from the UK Department for Environment, Food & Rural Affairs, and from a commercially available dataset from Vricon, a MAXAR Company.