Digital Geography

How to build your own QGIS plugin

Since I’ve created the QGIS plugin qgis2leaf I was surprised how easy it is to create a plugin for QGIS. In this post I would like to show you how to build a basic buffer-plugin and give some tips for debugging and developing. the plugin template QGIS plugins are competely build in Python: the UI can be designed with QT designer using PyQT. The whole logic of the plugin needs to be written in Python as well. But lets be honest: It would be great if you would have  a starting point. In QGIS there is a plugin for this called…

short announcement: new R learning material

Coursera, hail to Coursera. Despite the uprising criticism on MOOCs and their footprint in the educational landscape at universities Coursera created an interesting R learning course. It is divided and scheduled for 4 weeks and has video-tutorials as well as written material. The guys over at RevolutionAnalytics packed it all together: Content: Setting working directory and getting help How to get help Data Types Subsetting Vectorized Operations Reading/Writing Data Control Structures in R Writing Functions Avoiding loops using xapply Plotting Regular expressions Regular expressions in R Classes and methods in R It is a free course and is very userfriendly. The…

Earth in near real time: new Earth monitoring approaches

Since the start of Google Earth in 2001 (it was re-released in 2005 after Google acquired it from Keyhole, Inc ) remote sensing images made their way into every day life. But if you are looking at the images they show on Google Earth or Google Maps: You will see historic data and it strongly depends on companies like Digital Globe, BlackBridge (a.k.a. RapidEye) or Astrium and the contracts with Google whether you will see new or old data.

Anaconda: a interesting Python distribution

When working with GIS and statistical data there is an emerging need to know some scripting language. Python is one of the most widely used. It is not perfect but it is like a geographer: fairly good at nearly everything: “For scientific purposes, when writing a small specialized script, Python may often be the second best choice: for linear algebra, Matlab may have nicer syntax; for statistics, R is probably nicer; for heavy regular expression usage, Perl (ugh) might still be nicer; if you want speed, Fortran or C(++) may be a better choice. To design a webpage; perhaps you…

ArcGIS tutorial 1: how to georeference a map

ArcGIS is a geographic-information-system (GIS) developed by ESRI. Being widely used and the sheer amount of functions and add-ons are maybe the important causes for being a big-player at universities as well. Therefore we will present you some basic tutorials for learning an enjoying ArcGIS: Tutorial 1: how to georeference a scanned map in ArcGIS? objective To connect a scanned map with other geographical data the map needs to be refrenced. This meens, that every pixel in the scanned image gets a new dimension: besides its location in the image (e.g. 326th pixel from left and 124th pixel from the…

image georeferenciation using ArcGIS 10

Due to a recent article at our German partner geo-works.de I would like to share my two video tutorials for doing this. The first concentrates on the so called image-to-map georeferenciation. Imagine you have some aerial picture that clearly shows a very significant landmark. If you have the real-world geo-coordintes of that you can easily use this method to get your aerial photo joined by a georeference: Another thing is the usage of already georeferenced data like satellite images or shapefiles. This is the so called image-to-image georeferenciation (which is still similar to the mentioned above): So enjoy your new…

“Python” or the agony of choice

The work as a geographer with statistical and remote-sensing related focus arise the necessity of mastering a programming language sooner or later. Lets choose: C, C + +, Java,. Net, C #, VBA decide, etc., but you should ask yourself, what you want to do with your new skills. For me it was important to learn a possible open-source-based language construct. More important to me was the possible range of applications, simple language constructs and documentation, and a widespread use in GIS-related environments. The new language should also be a language that is compatible with applications that I already know…

getting to know open source GIS

in the next weeks I will produce a new series of how-to videos. They will cover the range of methods in GIS using open source GIS. As I am a fan of QGIS , I will present common tasks as explained in the book “Getting to know ArcGIS desktop” just by using QGIS instead. I hope you’ll enjoy it. If you have any tasks you would like see in QGIS just write a comment and I’ll try to cover them as well in the upcoming playlist. Stay tuned…

Geodatabases

In my years at the university i was playing around with a lot of data. These were sorted “somehow” and totally distributed. after a short while i have lost control and my pc behaved like HAL… One advice: USE GEODATABASES! YOu can see here how to do that using ArcCatalog