Digital Geography

Observing deforestation with Sentinel-1

While preparing for an upcoming presentation at the annual meeting of the American Geophysical Union (AGU) I came across a topic that I thought might make an interesting blog post.  The presentation is about using data from the Sentinel-1 mission for Earth Science applications.  The Sentinel-1 spacecraft are C-band SAR systems launched and operated by the European Space Agency (ESA).  An innovative aspect of this mission is that the collection scenario devised by ESA is systematic and very broad in coverage.  Using Sentinel-1 we can monitor Earth using SAR data like never before.

Extracting information from Sentinel-1

SAR images can see through clouds and in darkness, and are therefore very useful for operational monitoring of our seas. Detecting ships, icebergs, wind patterns, and oil spills is daily business in Europe with the Sentinel-1 satellite. Want to see for yourself how to extract information from a SAR image? In this tutorial, we’ll use the SNAP toolbox for Sentinel-1 to extract information on the number of ships at sea.

What is better: a map or a picture?

I was reading an article entitled “China, the megalopolis of 110 million inhabitants that impresses the world” on a popular online journal (see article) and after a dozen lines read: “Beijing is already surrounded by six ring roads, [… ] but the seventh will be 940 kilometers long.” How many are 940 km for example along a circle, as the Circular Highway of Milan?

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…

QGIS 2.2 on Ubuntu Trusty Tahr 14.04

QGIS on Ubuntu Trusty Tahr I’ve have started working nearly 100%, outside of work, in Ubuntu.  I was running Ubuntu 13.10 so naturally I decided to upgrade to 14.04.  My experience has been positive for the most part, but after the upgrade I was having issues with my install of QGIS 2.2.  Python – QGIS was not installing so I was not able to install any Plugins So after some digging I finally discovered that my “Software & Updates” repository for QGIS was still pointing to the Saucy Salamander (Ubuntu 13.10) package. So I changed my repository to the Trusty Tahr (Ubuntu 14.04), and…

Install QGIS 2.0 on Ubuntu

Today QGIS 2.0 was officially released and we will come up with several tutorials in the next weeks. First of all: the installation. As we are fans of open source we would like to show you the installation on a fresh build Ubuntu system: Installation on Ubuntu QGIS strongly depends on the grass libraries so as a first step we will install them: As QGIS 2.0 is not part of the official Ubuntu repositories (aka software provider) we need to enhance the list of software providers. Open up the terminal and edit the sources.list which helds this list: Now the…

OpenSource QGIS + PostGIS installation: “the Windows way”

A short time ago I’ve posted an article on the installation of QGIS in combination with a PostGIS database in the background. As we all know, Windows is mostly used as OS on a PC so this is the Windowized version. This is a short summary that sums up the article of a site called Boston GIS. I’ll show you how to install QGIS version 1.8 (which will be updated in some days) and PostgreSQL with PostGIS extension and show you the first steps in the import of shapefiles and raster data.

OpenSource QGIS + PostGIS installation: “the Ubuntu way”

A lot of you out there are probably working on Windows Systems using ArcGIS and I have to admit that the possibilities with ArcINFO in the background and a proper GDB (GeoDataBase) are really big. But let’s be honest: A lot of your tasks are more or less everyday business, right?! So let us have a look on building a GIS workplace using QGIS 1.8 (which will be updated the big way in some days/weeks) and PostGIS which is a spatial enhancement of PostgreSQL.