SHR3D

SHR3D classifies a 3D point cloud to generate simple geospatial products including a Digital Surface Model (DSM); a Digital Terrain Model (DTM); a classification image labeling ground, buildings, and trees; and a simplified building outlines vector product.

SHR3D Usage

./shr3d <Input File (LAS|TIF)> DH=<Horizontal uncertainty(m)> DZ=<Vertical uncertainty(m)> AGL=<Min building height(m)> <Options>
Options:
    AREA=<Min building area(m^2)>   Buildings smaller than this size will not be labeled (default: 50)
    EGM96                           Set this flag to write vertical datum
    BOUNDS=<MINX,MAXX,MINY,MAXY>    Set to define image bounds
    DTM=<DTM File (TIF)>            Path to optional DTM file
    GND_LABEL=<LABEL>               Set to the value of the point cloud ground classification label (typically 2) if the point cloud has already been partially classified.

Example:

./shr3d shr3dMe.las DH=0.5 DZ=0.5 AGL=2 AREA=50

This will produce multiple files as a result:

• Raster files (*.tif):
  • Classification image- 'Colored' by classification for each pixel: buildings, ground, and trees
  • Building image- Binary mask of all detected buildings
  • DSM- Digital surface model (reflective surface)
  • DTM- Digital terrain model (bare earth, or ground)
  • INT- Intensity image
• Vector files (shapefiles: *.shp, *.prj, *.shx, *.dbf):
  • Building outlines- Simplified polygons of detected building perimeters

ALIGN3D

ALIGN3D estimates and applies a transform to align 3D point clouds. This algorithm was developed for use with airborne lidar, multiple view satellite imagery, and synthetic aperture radar derived point clouds.

ALIGN3D Usage

./align3d <Reference point cloud(LAS)> <Target point cloud(LAS)> maxdz=<Maximum local z difference(m)> gsd=<Ground sample distance(m)> maxt=<Maximum XY translation for search(m)>

Example:

./align3d reference.las target.las maxt=10.0 gsd=1.0

This will produce multiple output files:

• Aligned.las- A point cloud representation of the target, aligned to the reference
• Aligned.tif- A DSM of the target, aligned to the reference
• Offsets.txt- A list of the xyz offsets to translate the target to align with the reference