I think 5/8" is a standard in surveying equipment. The adapter is needed to raise the center of perspective of the camera so that it is the same as the laser scanner. So it has dual functions. One is thread adapter, the other is height adjuster.
I can only imagine what they are doing. They use the laser scanner to get 3D point cloud data for the scene. The they take the pano at the same perspective. they render the pano into the 3D model as photo realistic texture.
I am glad they find NN3 adequate for they purpose.

Bill certainly did a good job in working out the partnership.
nick