Landscape Position using GDAL

Hat tip again to Seth Fitzsimmons. I’ve been looking for a good, easy to use smoothing algorithm for rasters. Preferably something so easy, I don’t even need to write a little python, and so efficient I can run it on 30GB+ datasets and have it complete before I get distracted again by the next shiny project (a few hours). Seth’s solution? Downsample to a low … Continue reading Landscape Position using GDAL

FOSS as Folk

Let us expand a bit on the theme of Free and Open Source Software as _Folk_ software development, i. e. of the people, for the people, and by the people. When I put together my presentation for FOSS4G Korea 2014, I had elements of this theme in it. I expected I would talk about the relationship between governance and open source software in the context … Continue reading FOSS as Folk

KNN with FLANN and laspy, a starting place

FLANN is Fast Library for Approximate Nearest Neighbors, which is a purportedly wicked fast nearest neighbor library for comparing multi-dimensional points. I only say purportedly, as I haven’t verified, but I assume this to be quite true. I’d like to move some (all) of my KNN calculations outside the database. I’d like to do the following with FLANN– take a LiDAR point cloud and change … Continue reading KNN with FLANN and laspy, a starting place

LiDAR and pointcloud extension pt 5

Now for the crazy stuff: The objective is to allow us to do vertical and horizontal summaries of our data. To do this, we’ll take chipped LiDAR input and further chip it vertically by classifying it. First a classifier for height that we’ll use to do vertical splits on our point cloud chips: And now, let’s pull apart our point cloud, calculate heights from approximate … Continue reading LiDAR and pointcloud extension pt 5

LiDAR and pointcloud extension pt 3

Digging a little deeper. Ran the chipper on a smaller number of points and then am doing a little hacking to get height per chip (if you start to get lost, go to Paul Ramsey’s tutorial). Here’s my pipeline file. Note the small chipper size– 20 points per chip. Easy enough to load (though slow for the sake of the chip size): Now we can … Continue reading LiDAR and pointcloud extension pt 3

LiDAR and pointcloud extension

Paul Ramsey has a great tutorial on using the pointcloud extension with PostgreSQL / PostGIS: You can get point cloud and all that goodness running a variety of ways. Probably the easiest is to download OpenGeo Suite from Boundless: If you are an Ubuntu user, try a docker instance to run PostGIS with PDAL, pointcloud, etc in a container: Also, I’m working … Continue reading LiDAR and pointcloud extension