3D Point Cloud Data Processing - Open Source Geospatial Tools: Applications in Earth Observation - page 262

Max X Y Z: 564678.43 5120950.88 2539.38

Spatial Reference:
PROJCS["NAD83 / UTM zone 10N",
GEOGCS["NAD83",
DATUM["North_American_Datum_1983",
SPHEROID["GRS 1980",6378137,298.2572221010002,
AUTHORITY["EPSG","7019"]],
TOWGS84[0,0,0,0,0,0,0],
AUTHORITY["EPSG","6269"]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433],
AUTHORITY["EPSG","4269"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",-123],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",500000],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
AUTHORITY["EPSG","26910"]]

...

We can also create a subset from the original point cloud with the option
--extent .

las2las -i st-helens.las --extent "561800 5118900 562000
→

5119100" -o st-helens_part.las

15% from the original point
cloud. Notice that double quotes are needed to parse the spatial extent. The command
also accepts comma separated values, in which case no quoting is needed. Another
way to reduce the number of points in a dataset is to split the LAS file into smaller
parts using the --split-mb (number of las files) or --split-pts (number of
points per las file).
We can also use las2las to convert the subset of the point cloud to an OGR
vector format. 12

The resulting LAS file contains 18,605 points, only 0 .

las2ogr -i st-helens_part.laz -o st-helens_part.shp

12 http://www.liblas.org/utilities/las2org.html