Shortly after the installation and initial testing, we presented the vehicle to Baker's management at their Fall Manager's Meeting. Shown above is a colorized point cloud of data captured in under 20 minutes. Colorizing a point cloud assigns a red, green, blue value for each measured point from the pictures taken with the onboard cameras. The image shows a decimated point cloud - where only 50% of the points are rendered.
During collection, we also captured portions of US 220. The image above is not a black and white photograph. It is an image comprised of millions of points rendered by the intensity of the returned light from the laser. The red lines denote a cross-section and the graph shows the profile. Note the superelevation of the roadway as the highway curves to the right. Nothing special was done to derive these images.
This is very impressive. This would take days with a traditional laser scanner (ie. Leica ScanStation). What is the ground shot accuracy through uncut/tall grass where you cannot see the actual ground? A traditional laser scanner will return the first thing that it hits. This is normally the grass canopy and not the actual ground shot.
ReplyDeleteTim,
ReplyDeleteOur system can measure 1st, 2nd, 3rd and last returns and has a relatively small spot size given the proximity to target. Therefore, we're able to obtain quite a bit of "bare earth" points. However in very dense, thicker grasses, we resort to subtracting height to account for the difference and to develop our bare earth model.