Digital Geography

How a QGIS plugin saved my day: autotrace

One of my favourite horror exercises for students was the digitization of geological maps. Everyone hated it as you need to take of snapping options, correct attributes, and always needed to check with the background map which was most of the times a bad quality scan of an old never-heard-of-this-country geological map. Today I needed to do this work for myself… what goes around, comes around.

regular spaced points… interpolation madness…

The geodata department of the city of Berlin offers a great portfolio of free geodata for everyone to use. One dataset is the result of some LIDAR measurements and is offered as a txt with x,y and d values. This is commonly known as xyz data but should not be mistaken as a simple whatever-delimited text file. This dataset is regular spaced and therefore can be threatened easily with QGIS. But let me first show you some interpolation results which can be produced as well. Interpolational madness If you want to create raster data from a point shapefile or a…

QGIS Plugins – Point Sampling Tool

Previous posts in this series QGIS Plugin – RasterCalc QGIS Plugin – OpenLayers Point Sampling Tool I have recently been working on a project that has required the extraction of information from a raster layer based on point positions in a vector layer. I’m not a big user of vector data, but I suspect this problem comes up from time to time. In my investigation of how to solve this, I found a great QGIS plugin, the Point Sampling Tool. The Point Sampling Tool allows you to easily extract values from a raster layer based on a vector point layer.…