redwoods and science enthusiast
CloudCompare is a powerful, open source 3D point cloud and mesh processing software available on all major platforms (Windows, MacOS, Linux). It is my current favorite tool for visualizing 3D point clouds.
Global elevation data is available through NASA’s Shuttle Radar Topography Mission (SRTM) program. For those interested, this blog post compares the resolution of elevation slope maps derived from the SRTM project vs. LiDAR data, and provides a brief background behind the two methods. LiDAR, in short, provides for much higher resolution Digital Elevation Models (DEMs).Continue reading Using LIDAR ground points to generate a DEM (Digital Elevation Model) and Contours using PDAL and SAGA
Recent versions of SAGA GIS no longer support importing files in the .las format. However, a .las file can be converted using PDAL’s writers.text module into a text file format, which in turn can be imported in SAGA. For this example, we will begin with a .las file projected in a state plane CRS thatContinue reading Converting LIDAR .las Point Clouds for Viewing in SAGA GIS using PDAL
Download one or more lidar tiles: wget https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/5008/20131013_usgs_olympic_wa_10TDT310990.laz Note the source crs (coordinate reference system, i.e. projection). This 2013 USGS Lidar: Olympic Peninsula (WA) Point Cloud dataset from NOAA uses EPSG 4269. This means that the point cloud coordinates are using latitude/longitude, which is not well supported by many downstream GIS tools. Running lasinfo https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/5008/20131013_usgs_olympic_wa_10TDT310990.lazContinue reading Reprojecting LIDAR .las files – Latitude/Longitude to State Plane Example