PDAL on the VDI: Setup and metadata examination

Add PDAL in the module load system

PDAL operates in the NCI module load system. To get started, open a new VDI terminal screen and type:

$ module load PDAL

Investigate the results:

$ module list
Currently Loaded Modulefiles:
  1) pbs                       3) proj/4.8.0
  2) gcc/4.7.3                 4) pdal/1.3.0-py3.5(1.3.0)

The PBS module is loaded by default on the VDI. What we get alongside PDAL/1.3.0-py3.5 is proj/4.8.0, required for or reprojection tasks in PDAL; and gcc/4.7.3 is loaded as part of the module load process.

Note we have a strong hint here for using PDAL's Python modules later - we need to use Python 3.

Check that PDAL works

A simple operational check is to grab some metadata from a LAS file. We'll use the Geoscience Australia elevation reference dataset, hosted on NCI at /g/data/rr1/Elevation

In particular, we'll use a LiDAR survey flown over Merimbula in 2013:


If you're a GDAL user, PDAL metadata querying will look familiar:

pdal info /g/data/rr1/Elevation/Merimbula0313/z55/2013/Mass_Points/LAS/AHD/LAS/Tiles_2k_2k/Merimbula2013-C3-AHD_7605910_55_0002_0002.las

This will return a long JSON output stream telling you all about the LAS tile you queried, and basic statistics on each of its dimensions.

If you got this far, you have a working PDAL - and you've used it for a metadata query!

Metadata exercises


pdal info

...to get some other options and see if you can:

  1. Return a shorter set of metadata
  2. In this metadata, find the LAS file format major and minor version (hint - using 'grep' will make your life a lot easier
  3. Return a polygon showing the geospatial extents of the file you queried.
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