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.

Geospatial cloud solutions: Software-as-a-Service vs Roll-your-own

Over the last couple of years, we have seen an increase in demand and offerings of geospatial solutions in the cloud for tasks like web map creation, centralized data storage and management, data vizualization and so on. There is a lot of Software-as-a-service (SaaS) options to explore, but in this article I want to briefly discuss if SaaS is the right thing for you, or wether you should look into rolling your own.

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?

Create Maps Online: A comparison of 6 webmap providers

Working with a desktop GIS might be a good choice for geodata-experts, GIS-people in general and everyone who is inside the fields of geosciences. If you don’t want to struggle with a desktop mapping software or you “just want to create a map” for your publication, business data, website or professional service the following online mapping solutions might be the one-stop-shop for your needs.

Pros and Cons of using Smartphone as a GPS Tool

In a statistical report entitled US Smartphone Use in 2015, it revealed that some 88 percent of American smartphone owners use their handset as a map or navigation device. There are various ways on how you can utilize your handset as a GPS device, either through its built-in map features or via other downloadable applications. If you are one of those planning to maximize their smartphone as a GPS locator, here are the pros and cons of using your handset as a digital geographical tool.

Python in QGIS and ArcGIS: A Small Example

Often the usage of GIS never touches the world of programming and I think a lot of GIS users today feel fine with using simple tools and try to avoid tools like Python for their daily work. Despite any prejudices regarding programming, Python can be a big help in your basic tasks and is a very easy scripting language to learn. So let us check out Python in ArcGIS and QGIS with a buffer analysis as an easy example. Nevertheless I recommend to take some coding lessons in Python using CodeAcademy.

DEM comparison: SRTM 3 vs. ASTER GDEM v2

Let’s get ready to rumble! No, just kidding. We are all excited about the recent message from the white house: SRTM “1” (1 equals 1 arcsecond, whereas 3 was indicating the 3 arcsecond a.k.a. 90m DEM) or the official title SRTM-2 will be available for free in the next months (orig. here, dg here). So why is it so important? Most DEM-interested people will answer: “Use the ASTER DEM if you need 30m!”. But let us have a closer look on both systems and how they perform.

ArcGIS server vs. Open Source GIS solutions

originally posted from our friends @mappinggis Which program is better suited to serve geographic data on the web? ArcGIS Server form ESRI or open source ? This question is common in mailing lists and GIS-forums. The most consistent answer is that depends on the project. But in this post we will see some numbers to determine which is the best software to develop an application for web mapping:

MatLab, SAS, STATA, SPSS, Excel users: Try R, damn it!

Due to my work with a multitude of statistical packages in my career I may be able to evaluate a lot of them. I’ve first used Excel for my calculations as most of the normal users do. I like the idea behind a spreadsheet and the combination of data and click-to-do functions. Nevertheless I’ve often managed to gain control again over my spreadsheets as they’ve evolved to some unintelligible things on my hard drive. The ruler of this evolution was spreadsheet “data_results_0.9.1a_final_b_ws.xls”…

types of web-maps: concepts and possibilities

In my recent articles I was writing some hints and tutorials for creating a webmap. So what is the basic concept behind it and what are the possibilities. 1. Hail the GMAP creator GoogleMaps was probably the main step in webmap perception and usage. Until now it is the quasi standard application for viewing spatial content. The ongoing developments in the keyhole markup language increases the possibilities and usability in everyday work including geocoding and usage of raster as layers:

NDVI / SAVI calculation using Landsat scenes: DNs vs reflectance values

In one of my last seminars relating remote sensing techniques I was blamed for calculationg the NDVI and SAVI directly with the ModelMaker in Erdas Imagine using digital numbers (so-called DNs) instead of reflectance values. So I analyzed the influence of using DNs instead of reflectances. You can see some little thoughts and results on that here…