These types of pointclouds are generated when operating on an aerial platform and:
- the lidar is tipped more than 45 degrees from horizontal and the drone moves in a direction tangential to the scanning planes of the lidar.
- the lidar is flown higher than 15 meters (50 feet) even if the lidar is mounted horizontally. Consider, when the lidar is tilted on an aerial platform, more than half of the lidar returns are looking at empty sky reducing the number of points for lidar scan matching considerable
The first picture on the left is from a downward looking lidar with few lidar returns from the ground due to height.
The second picture on the left is from an aerial platform with a highly pitched lidar sensor with more ground returns, but the area is fairly flat. Sometimes these look entirely spherical. Some of our most interesting artwork comes from scans like these.
Kaarta’s algorithms work best on aerial platforms when the lidar is horizontal, the flight is smooth, less than 9 meters (30 feet) high, and most of the horizontal field of view is not occluded to minimize the amount of vertical drift.
Stencil with a camera can collect data and generate fully registered point clouds even a high tilt angles.