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ST_Buffer on Geography — Iteration
In my previous post, Imagico said: This is nice but still fails in one important aspect – it will create significant inaccuracies once your buffering distance reaches values where buffering in a single...
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Yet another approach to ST_Buffer on geography
Another approach to ST_Buffer would be to subdivide the geometries before buffering, and put them all together at the end. ST_SubDivide can do this for us. We can tell it how may vertices we want in...
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Taking Slices from LiDAR data: Part V
For this post, let’s combine the work in the last 4 posts in order to get a single pipeline for doing the following: Calculate relative height of LiDAR data Slice that data into bands of heights Load...
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PostgreSQL table drop — a little fun with ouroboros
My latests posts on PDAL have been fun. For the moment, a quick bit of code for dropping all the tables in your PostgreSQL database. BTW, the following is a bad idea. Many bad ideas are really useful....
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Taking Slices from LiDAR data: Part VI
I finally got PDAL properly compiled with Point Cloud Library (PCL) baked in. Word to the wise — CLANG is what the makers are using to compile. The PDAL crew were kind enough to revert the commit which...
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Using foreign data wrapper to use PostGIS with SQLServer
Here was the problem that needed solved last week (we have a few similar problems in upcoming projects, so this was an exciting thing to try): we needed to use PostGIS to access data in a SQLServer...
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Taking Slices from LiDAR data: Part VII
Part 7 of N… , see e.g. my previous post on the topic. More work on taking LiDAR slices. This time, the blog post is all about data preparation. LiDAR data, in its raw form, often has scan line effects...
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Taking Slices from LiDAR data: Part VIII
Part 8 of N… , see e.g. my previous post on the topic. I didn’t think my explanation of sampling problems with LiDAR data in my previous post was adequate. Here are a couple more figures for...
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Taking Slices from LiDAR data: Part IX
Part 9 of N… , see e.g. my previous post on the topic. We’ve been working to reduce the effect of overlapping samples on statistics we run on LiDAR data, and to do so, we’ve been using PDAL’s...
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A little Gorilla Time
I miss my mountain gorilla friends in Rwanda. Let’s write a little more code to support them. I’ll be visiting Karisoke again next week, so it seems timely to post a little more code (HT Jean Pierre...
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