As new technologies go, few look as futuristic and as hi-tech as LiDAR which stands for LIght Detection and Ranging or Laser Imaging Detection and Ranging. Even the name makes it sound futuristic. However, LiDAR is merely a remote sensing technology that uses laser light sensors mounted on either vehicles or aircraft to illuminate a target in order to gather the appropriate data. Notice the animation to the right showing a simplistic view of a laser identifying surface area (from wikipedia). The result of a LiDAR collection is what is called a point cloud or a 3D image made up of points representing the external surfaces of the target objects. A single sensor may collect up to 800,000 X, Y, and Z points per second to create a 3D model and animations.
Today, LiDAR is used in a wide variety of disciplines including geomatics, geology, geomorphology, bathymetry, forestry, archeology, contour mapping, gaming, and even music videos. Apparently the indie rock band Radiohead thought it was cool enough to create an entire music video based on the technology. Whether or not you’re a fan of their music, it’s interesting to see an artistic view of LiDAR.
Here is the Radiohead video link: http://www.youtube.com/watch?v=8nTFjVm9sTQ
LiDAR and Outdoor Advertising
Having completed multiple outdoor advertising projects for states working to keep compliant with the Highway Beautification Act (HBA), we know that the largest and most expensive portion of a statewide review process is the field inventory. So we set out to research and test several available technologies and methodologies in order to identify the most efficient and cost effective approach. We objectively reviewed the various approaches–from the old-fashioned, manual mapping method (taking a picture of each sign and capturing a GPS point), to a mobile mapping solution using multiple high resolution cameras and LiDAR, coupled with GPS and IMU. Not only did we review the options on paper, but we also used both approaches during a pilot project in order to have a true benchmark of results. The mobile mapping solution (combination of LiDAR and mounted cameras) was the clear winner: It offered greater driver safety, reduced collection time, better positional accuracy, value added image and LiDAR datasets, and a substantially larger and more diverse collection of images, such as multiple views from various distances and edge of pavement. The following table represents some of the findings from the pilot.
The great thing about a LiDAR data set is that is isn’t a use it once for a single purpose and throw it out – It’s the technology that keeps on giving. Additional data that can be extracted includes bridges and clearance, medians, curb and gutter, vegetation, guard rails, rumble strips, tunnels, passing lanes, centerlines, ditches, overpasses, rutting, concrete barrier walls, edge of pavement, and more.
I can attempt to write about the output from a photo log / LiDAR billboard collection all day but I assume you would rather see it than read about it – so here you go.