The LAS specification requires that the File Source IDs and the Point Source IDs match (i.e. are the same number) when the LAS file contains data from a single flight line, drive pass, or strip of data. To ensure that this requirement is met, we can use a combination of TerraScan and GeoCue processes. Step…
The United States Geological Survey (USGS) has developed a national 3D elevation program (3DEP) as part of its National Map initiative. The National Map is a collaborative effort among the USGS and other Federal, State, and local partners to improve the publicly available topographic information for the United States. The 3DEP layer of the National…
Quality control and quality assurance checks for LIDAR data continue to evolve as the industry identifies new ways to help ensure that data collections meet desired usage requirements. The U.S. Geological Survey (USGS) LIDAR Base Specification introduced a definition for spatial density distribution and regularity within LIDAR data. The requirement is that the spatial distribution…
In the previous issue of LP360 News, I introduced the use of Triangulated Irregular Networks (TIN) for modeling point derived elevation data as well as the basic concepts of “soft” breaklines. I realized when writing that first article that it is probably a useful exercise to review contours. Thus this part II article will be…
Pierce County, Washington has used LIDAR data since 2004 as a mission critical component of the County’s Geographic Information System (GIS). The data, collected from 2000 to 2004, has been used for a variety of purposes, including economic development, environmental planning, construction and transportation projects, and emergency management. However, this data was collected with older…
