Smathermather's Weblog

Remote Sensing, GIS, Ecology, and Oddball Techniques

LiDAR and pointcloud extension

Posted by smathermather on July 8, 2014

Paul Ramsey has a great tutorial on using the pointcloud extension with PostgreSQL / PostGIS: http://workshops.boundlessgeo.com/tutorial-lidar/

Image of lidar chipped into 400 point envelopes

You can get point cloud and all that goodness running a variety of ways. Probably the easiest is to download OpenGeo Suite from Boundless: http://boundlessgeo.com/solutions/opengeo-suite/download/

If you are an Ubuntu user, try a docker instance to run PostGIS with PDAL, pointcloud, etc in a container:

https://github.com/vpicavet/docker-pggis

Also, I’m working toward a simple installer script for Ubuntu 14.04 and for Vagrant, which is a fork of Vincent’s docker install:

https://github.com/smathermather/labr-pdal

One tip for those using, say QGIS instead of GeoServer for connecting and visualizing your data. Change any views created on the fly to tables, e.g.:

CREATE VIEW medford_patches AS
SELECT
  pa::geometry(Polygon, 4326) AS geom,
  PC_PatchAvg(pa, 'Z') AS elevation
FROM medford;

change to:

CREATE TABLE medford_patches AS
SELECT
pa::geometry(Polygon, 4326) AS geom,
PC_PatchAvg(pa, ‘Z’) AS elevation
FROM medford;

CREATE VIEW medford_patches AS
SELECT
  pa::geometry(Polygon, 4326) AS geom,
  PC_PatchAvg(pa, 'Z') AS elevation,
  id
FROM medford;

QGIS doesn’t like those views with casts for some reason… . without an id.

If the code I’m working on now works, it will do some height calculations using pointcloud, will show up on Github, and may include a little bonus pointcloud tutorial here. Stay tuned.

6 Responses to “LiDAR and pointcloud extension”

  1. Regina Obe said

    Steven,

    What happens if you include an Id in your view? I recall QGIS having issues with views if no integer id is exposed. Perhaps it doesn’t have the same issue with tables.

  2. Just noticed another way to get this running for Windows users (I shouldn’t be surprised): http://www.bostongis.com/blog/index.php?/archives/220-PostGIS-pointclouds-extensions-windows-binaries.html

  3. Regina Obe said

    I actually got as far as building the PDAL loader too (just basic no hdf/laszip), but basic las. Unfortunately last I tried the 32-bit would segfault on largish point clouds but the 64-bit was okay. I should revisit that. Would be nice to provide a complete package with PDAL loader included for PostGIS 2.2. Then we’ll have pretty much the full shebang of PostGIS w. SFCGAL and Point Cloud (extension/loader) for windows users 🙂

    • (Hijacking this thread) — You indicated in a recent post (that I can’t seem to find) that and operators would effectively be able to be used in WHERE clauses with 9.(4?) — did I dream this? ‘Cause that would make KNN calcs so important for point cloud manipulation really easy.

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