Digital Geography

ALOS World 3D V1.1 vs. SRTM1

Some days ago a new version of the ALOS 30m DEM was released: Void pixels due to clouds and snow pixels within 60 deg. of north and south latitudes in Version 1 were complemented by existing DEMs. Out of the areas are same with Version 1 product. As we already compared ALOS with SRTM-1(I saw the ALOS DEM as “the winner”) I am now interested in how this performs in a another setting. We are changing our focus from Mongolia to Germany and check how the new ALOS DEM works compared with SRTM 1.

Military Expenditure on a map

Statistical data for a geographer is fun! War is not! Regardless what you think of the military it never hurts to be informed, so… Lets play a bit with military expenditure statistics. I’m using data from SIPRI (Stockholm International Peace Research Institute), which covers military expenditure for regions and countries based on for instance GDP. The data is in Excel format (.xlsx) which is a problem for QGIS, so it has to be converted to a format that QGIS understands. First however some other issues must be addressed. In order to use the years as field names they must be…

The PCA plugin for QGIS

When it comes to data we are more or less lost nowadays. We can acquire more and more data for a current area and find answers on our questions. The Principal Component Analysis (PCA) can help you to enhance your understanding your data and to reveal underlying information that influences your data fundamentally. Since some days there is a special plugin for QGIS available that enables you to determine principal components from your 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…