The LAS Domain Profile is a derivative of the base LAS v1.3 specification that adds but does not remove or alter existing point classes and attributes.
It is designed to support topographic-bathymetric (“topo-bathy”) LiDAR, according to Chris Parrish, the LiDAR division’s assistant director and the lead physical scientist with the remote sensing division of NOAA’s National Geodetic Survey. The Topo-Bathy LiDAR Domain Profile adds point classification values for bathymetric point (for example, the seafloor), water surface, derived water surface, submerged object, IHO S-57 object, and bottom-not-found-depth.
Extra Byte Variable Length Records (EXTRA_BYTEs or Extra Byte VLRs) are added for pseudo-reflectance, uncertainty, water column depth, figure of merit and processing specific flags. A LAS Domain Profile Description Template is available online.
The LAS format, which is published and maintained by ASPRS, is a public file format for the exchange of 3-D point cloud data between users. The new point classes and attributes defined in this domain profile further extend its utility by facilitating the production and use of point clouds containing both subaerial (i.e., land) and subaqueous points.