Author: smathermather

My primary interest is in understanding ecological processes in a synoptic fashion. This has led me down a long study with Geographic Information Systems and Remote Sensing as they relate to ecology and biological processes.
Other

UAS Mapping: Positional Accuracy Assessment via GeoKota

Introduction Recently we partnered up with folks from the University of Akron to help determine how accurate UAS are compared to traditional mapping methods. Given the current difficulty to fly commercially in the National Airspace, this partnership gave us a unique opportunity to fly inside their Field House. This controlled space had a lot of […] via UAS Mapping: Positional Accuracy Assessment — GeoKota Continue reading UAS Mapping: Positional Accuracy Assessment via GeoKota

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Other

The Worlds of #Mapzen Sphere Maps

Guest blog post today from Brandon Garman (@brandon_garman): After seeing Mapzen’s blog post on Sphere Maps, I wanted to try my hand at it. I downloaded the Github repository, set up a python simple server and ‘BOOM’ had my own instance running (Mapzen makes this process very easy). So next I pulled out my Wacom tablet, opened up Photoshop and began painting in circles with … Continue reading The Worlds of #Mapzen Sphere Maps

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3D, Image Processing, OpenDroneMap, OpenDroneMap, Optics, Other, Photogrammetry

Viewing Sparse Point Clouds from OpenDroneMap — GeoKota

This is a post about OpenDroneMap, an opensource project I am a maintainer for. ODM is a toolchain for post-processing drone imagery to create 3D and mapping products. It’s currently in beta and under pretty heavy development. If you’re interested in contributing to the project head over here. The Problem So for most of the […] via Viewing Sparse Point Clouds from OpenDroneMap — GeoKota Continue reading Viewing Sparse Point Clouds from OpenDroneMap — GeoKota

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Database, PostGIS, PostgreSQL, SQL

Using PostGIS for Hydrologic Modeling (reblog)

The Problem We have to filter out the roads and ditches without removing streams that cross roads or follow them closely. I’m going to use PostGIS to find the intersection of the streams lines data with a buffered roads polygon. If the intersected line is less than 50% of the length of the stream line, […] via Filtering Roads from Extracted Streams Data — GeoKota Continue reading Using PostGIS for Hydrologic Modeling (reblog)

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Database, PostGIS, PostgreSQL, SQL

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 database. The SQLServer database backs the web site in question, the underlying content management system, etc., so no– removing SQLServer isn’t really an option at this stage. Obviously … Continue reading Using foreign data wrapper to use PostGIS with SQLServer

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GDAL

(Whichever tiler you use) and efficient delivery of raster data (image pyramid layer) (update2)

Subdivision of geographic data is a panacea to problems you didn’t know you had. Maybe you deal with vector data, so you pre-tile your vector data to ship to the browser to render– you’re makin’ smaller data. Maybe you use cutting edge PostGIS so you apply ST_Subdivide to keep your data smaller than the database page size like Paul Ramsey describes here. Smaller’s better… . Or perhaps you … Continue reading (Whichever tiler you use) and efficient delivery of raster data (image pyramid layer) (update2)

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FOSS4G-NA

~~North Carolina GIS~~ rhymes with Lasagna

Last year I really enjoyed attending and presenting at North Carolina GIS in Raleigh. As many of you know, Free and Open Source Software for Geospatial North America (FOSS4GNA, alleged by some to rhyme with “lasagna”) will be in Raleigh this year, in a short few weeks. I highly encourage you to go. First of all, it’s FOSS4GNA, so lots of free and open source geospatial … Continue reading ~~North Carolina GIS~~ rhymes with Lasagna

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3D, OpenDroneMap

OpenDroneMap — texturing improvements

Great news on OpenDroneMap. We now have a branch that has MVS-Texturing integrated, thanks to continuing work by Spotscale, and of course continuing integration work by @dakotabenjamin. The MVS-Texturing branch isn’t fully tested yet, nor fully integrated, but the initial results are promising. MVS-Texturing itself handles the problems of choosing the best photos for a given facet on a textured model in order to do … Continue reading OpenDroneMap — texturing improvements

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3D, Database, Docker, LiDAR, Other, PDAL, pointcloud, PostGIS, PostgreSQL

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 broke GCC support, but why swim upstream? If you are compiling PDAL yourself, use CLANG. (Side note, the revert to support GCC was really helpful for ensuring … Continue reading Taking Slices from LiDAR data: Part VI

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