The Benefits of Simultaneous Multi Sensor LiDAR Scanning
In May, Jordan compared and contrasted LiDAR and Photogrammetry as competing service types. While some projects choose one modality over the other, we feel it is in many customers best interests to consider both LiDAR and aerial imagery – multi sensor LiDAR scanning. With the availability of lower cost aerial survey brought on by the use of UAVs, companies should also consider the potential value of choosing a provider that offers multi sensor deliverables.
LiDAR is the reigning king of accuracy and is usually simpler to capture, process, and deliver. Aerial imagery provides details and visuals that cannot be obtained by LiDAR. When the two are combined, there are several advantages. Multi sensor scanning combines an aerial camera and LiDAR on one platform that shares trajectory data in a single package.
Capture and Processing Workflow Streamlined for Imagery
when Combined with LiDAR.
A well integrated multi sensor system uses the same motion and position tracking data (IMU/GNSS trajectory) for both sensors during a simultaneous acquisition. As a result, orthorectification of the images is quickly and easily accomplished, eliminating the need for extensive ground control points normally required for accurate photogrammetry. Since elevation and terrain modeling is accomplished with the LiDAR system, the orthorectified images are sufficient for most deliverables without the need for photogrammetry processing. For large areas this processing can be time and resource intensive. In addition to requiring processing resources, traditional photogrammetry requires significant horizontal and vertical overlap to achieve elevation accuracy. This complicates data capture and raw data storage requirements, especially for larger areas. In contrast, orthorectified images require minimal overlap since elevation and terrain data is derived from the LiDAR 3D data.
LiDAR Accuracy + Photogrammetry Visualization…Now in
When LiDAR and orthorectified images are combined with adequate control, the result are highly detailed and accurate products. The low imaging altitudes possible with a UAV and high resolution digital cameras provide incredibly high pixel densities and amazing detail. Combine this with the latest LiDAR technology at those same low altitudes and slow capture speeds, and you get previously unheard of point cloud density. The limiting factor for the deliverable becomes the clients preference for level of detail and file sizes.
Reduced Cost – Multi Sensory LiDAR Scanning
When acquisition and processing are simplified with multi sensor LiDAR scanning, the cost of aerial imagery and LiDAR is substantially lower than obtaining both as separately acquired services. With an integrated platform, all data is captured with a single flight plan. Processing is done quicker and easier, and the result is less work and expense for data providers. These savings are then passed on to the client.
Multi sensor capture is not required for every job. But for many situations, a data provider that is able to capture both LiDAR and imagery in a single flight can save time and money. When using UAVs for smaller jobs that previously would not have been able to afford aerial products, it is now possible to have both LiDAR and aerial imagery at a compelling price. For larger jobs, the level of detail and simplicity of capture means that UAV systems are competing where helicopters and planes previously dominated. At the end of the day, a provider offering UAV multi sensor data capture can be a great asset to almost any job.