Digital Geography

QGIS 2.16 tutorial: georeferencing images

Since our last tutorial regarding georeferencing images in QGIS is 4 years old, let us have a second look at this task in the current times of QGIS 2.16. For this tutorial we will use a Soviet map of Crewe in England to see changes in city structure with a snapshot from 1957. We will use simple and quite easy affine transformations for this purpose.

Accessing Landsat and Sentinel-2 on Amazon Web services

The cloud has made it easier to process large amount of data, and satellite imagery processing benefits from cloud processing too. One of the cloud services that offers access to satellite images, and abilities to process them in the cloud – no more need to download it to your computer and process it there – is Amazon Web Services. If you’ve never worked with cloud processing, getting started with AWS can be a bit daunting. This tutorial gives beginners an introduction to accessing satellite images – Landsat and Sentinel-2 – on AWS.

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.

First images from recently launched Sentinel 2 satellite

The earth observation satellite Sentinel-2 with Sentinel-2A and Sentinel 2B was launched on June 23rd 2015 from space centre Kourou in French Guiana. The mission is part of the Copernicus mission by ESA. The liftoff was recorded by ESA and can be watched here. Sentinel will be a complement to the multispectral satellites of the Landsat mission and SPOT. All observation systems in combination reveal a higher temporal resolution by shifted orbits and large stripe widths (Sentinel: 290km). Sentinel has a repetition rate of 10 days, Landsat 8 of 16 days but in combination with Landsat 7 a 8 day…