Digital Geography

PostgreSQL and PostGIS: A brief introduction

You probably seen this already (maybe on your very own PC as well): A folder with shape files. Well we’re living in the 21st century and I do have and use those folders still. After a talk of Sebastian Meier at Maptime Berlin I was convinced and started to work with a databases instead of folders. So let me show you how to install PostgreSQL along with PostGIS on Ubuntu and Windows, how to get data into it, import OSM data and how to connect it with QGIS/ArcGIS.

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.

Import OSM Data Into A PostGIS Database (The Easy Way)

I often find myself in a situation where I want to work with large areas and datasets of OpenStreetMap data. No matter if you want to use them in a QGIS map or create custom map tiles in Tilemill, with the Overpass API you quickly run into performance issues. Imposm is a great tool to overcome that situation, so you can load OSM extracts (worldfiles in pbf format) with a custom data mapping into a PostGIS enabled PostgreSQL database. The downside: It is hard to set up if you are not a database and system admin guru. This is where…

Panorama Geodata eXtractor

It’s been a while since I wrote here on DG, but I’ve been busy writing on my own blog in Swedish. However, now it’s time to reveal something I’m pretty pleased with, that you maby can use as well. A simple (well reasonably so) method to extract geodata from panoramic photographs, by using open javascript libraries, some javascript of my own and a lot of head scratching.

Some ways to produce high-res DEMs – tools and data

Many of us use digital elevation models (DEMs) for a whole bunch of different applications. There are some standard products which everyone should know, like SRTM1, SRTM3, ASTER, GLOBE or ETOPO1 for the land surface or GEBCO for bathymetry. However, they have a relatively low resolution and are therefore not suitable for all purposes. During the last few years there has been a huge progress in producing much better DEMs, especially local ones, using a wide range of techniques like LiDAR, photogrammetry, image correlation, structure-from-motion (SFM) etc. Some of these techniques make use of powerful, but expensive equipment (e.g., LiDAR),…

Open Data in the UK

The Ordnance Survey is UK’s mapping agency and frequently releases free datasets. Their OpenData policy is quite progressive compared to Germany’s and they’ve recently published some fresh datasets that anyone can use. All you need to do is to register and to acknowledge them. The new datasets are: OS Open Map – Local; OS Open Names; OS Open Rivers; and OS Open Roads. They include data on urban and rural features, an index for all the location names in the UK, a generalised open water network, UK’s connected road network and much more. All this adds up to their existing…

Landsat in Love with QGIS: the newest coup from Luca

The normal way of getting Landsat data for your GIS projects often was: visit a Landsat data mart like landcover.org, earthexplorer or WIST, search for your area and time and download/order your desired data. Once you’ve done this, you were prepared to add, analyse and publish this data/results with QGIS. Luca Congedo from the blog “From GIS to Remote Sensing” .

ArcGIS Open Data

For a year, ESRI’s open data initiative is online. As I’ve heard about it for the first time I was just thinking: nice move to get people into their ArcGIS online environment. But I have to admit: I was not looking and exploring their platform. Now I stumbled upon a recent post on reddit and there it was again: opendata.arcgis.com has 25,000+ open datasets all accessible by a common API. Full disclosure: I work on the team that builds the product. So let’s have a look at it…

Short Announcement: new MOOC on GeoInt!

Today I received an interesting E-mail from Pennstate University which pointed towards an upcoming MOOC with a more or less special focus: Geospatial Intelligence. The title is Geospatial Intelligence & the Geospatial Revolution: Learn how the revolution in geospatial technology combined with the tradecraft of Geospatial Intelligence (GEOINT) have changed how we develop insights about how humans use geography, and discover the power of GEOINT. So let’s have a look at.

DataSF or how to do open data right

In 2010 the City and County of San Francisco’s official open data portal was launched. To me it is the ultimate experience for publishing/consuming open data: based on a WordPress system the city distributes data for several categories: Economy and Community City Management and Ethics Transportation Public Safety Health and Social Services Geographic Locations and Boundaries Energy and Environment Housing and Buildings City Infrastructure Culture and Recreation There are 820 datasets available at the moment. Depending on the source of the dataset you will either be able to download the data directly or to display it as table: You can…

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.

Advanced access to free climate data for Germany of the Climate Data Center

Since July 1st 2014, the Deutscher Wetterdienst (DWD) eased restrictions for the usage of climate data and provides users with a big dataset of free climate data for Germany. You can obtain the data, using the FTP-Server of the Climate Data Center (CDC). The following data in the following resolutions and formats are ready to download for free: measured Paramater at the DWD-Stations for climate in hourly, daily, monthly and annual resolution and phenology in annual resolution as txt derived Paramater at the DWD-Stations for soils (pot. and actual evaporation, soil moisture, soil temperature, max. depth of frost penetration over…