ArcGIS REST API Connector Plugin for QGIS

ArcGIS REST Connector Plugin

Last year we described a command line method that adds ESRI REST layers in QGIS. Well, a team at the Geometa Lab in the University of Applied Sciences Rapperswil (HSR) Switzerland, have released a plugin for QGIS that adds ESRI REST layers via a GUI (Github page). The plugin is experimental so you will need to tick the box “Show also experimental plugins” in the settings panel of the “Plugins – Manage and Install Plugins” dialogue in order to add the plugin to QGIS. The following URLs lists numerous REST layers in the plugin’s GUI:

http://services.arcgisonline.com/arcgis/rest/services

http://basemap.nationalmap.gov/arcgis/rest/services

http://services.nationalmap.gov/arcgis/rest/services

Reference:

REST API Connector Plug-in Wiki Page

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Oceancolor Data Downloader v1.0 for QGIS

Aqua Modis SST 2015-01-13

Sea Surface Temperature data downloaded by Oceancolor Data Downloader.

The Oceancolor Data Downloader is a new plugin for QGIS from the Mapping and Geographic Information Centre of the British Antarctic Survey that downloads Oceancolor and Sea Surface Temperature data from NASA’s Oceancolor website. The plugin currently downloads three datasets:

  • MODIS AQUA chlorophyll concentration
  • SeaWiFS chlorophyll concentration
  • MODIS AQUA night time Sea Surface Temperatures

The data accessed includes daily, 8 day, monthly and yearly composites, all of which can be saved to disk while downloading. Future plans for the plugin include additional access to other datasets such as ocean Net Primary Production, selection by bounding box, the ability to save in other formats, a progress bar etc.

I used the plugin to download global Sea Surface Temperatures for the 13th Jan 2015. I then used shapefiles from Natural Earth to create a simple basemap. I finally chose the IBCAO Polar Stereographic projection (EPSG: 3996) to create a map centred on the North Pole.

If you use the plugin to produce published research, please cite:

10.5281/zenodo.15018

The 10th annual FOSS4G conference

The 10th annual FOSS4G conference was held from 8th-13th September in Portland, Oregon, USA. FOSS4G is the world’s premier global gathering of developers, users and key decision-makers involved in open source geospatial software. With over 180 talks presented covering topics from 3D printing maps with Grass GIS 7 to QGIS Map Server and beyond, FOSS4G 2014 was a resounding success. Don’t be disappointed if you could not attend, all the talks given at FOSS4G 2014 are now viewable on Vimeo, including 8 one hour invited presentations from staff at Amazon, MapZen, Boundless, Mapbox etc. These talks are well worth watching if you want to keep up to date with the latest developments in open source geospatial software.

FOSS4G 2014 General Sessions – Talks and Invited Presentations

New Online Beginners Course in QGIS 2.2

A US government funded education institution, the National Information Security and Geospatial Technologies Consortium (NISGTC), is offering a free online beginners course to QGIS 2.2 (GST 101 QGIS 2.2). The seven module course is based on the Introduction to GIS course run by Rick Smith with new course material and tutorials specific to QGIS added by Kurt Menke. The course is in beta form at this time with an official launch planed for August 2014 on GitHub, enrolment is open to all.

Here is the course introduction:

Welcome to the QGIS introductory GIS course.  Please note that this course shell is in beta.  We appreciate your willingness to evaluate our course material in preparation for publication in August 2014.  We are very excited that this new series of five complete GIS courses, all based on Open Source Software, will provide educators the curriculum and tools they need to adopt open source GIS software into their GIS programs.

We ask that you follow the sequence of modules presented in the Modules and complete the lab assignments one at a time.  You are welcome to make remarks on either in the discussion area for each module.  Please note that this is a self-paced, open enrollment, course without instructor support or presence.  We make this material available to the public for their own use.  We will publish the course officially on Github in August 2014.  Anyone is welcome to reuse any of the material at that time for their own courses, with attribution under Creative Commons BY license.

NISGTC: GST 101 QGIS 2.2. Course Enrolment Page

10 years of QGIS on Google Trends

Here is a graph showing how often people entered the search term “QGIS” into Google over the last 10 years. It was generated using Google Trends, a Google utility that displays trend graphs and basic regional statistics of search terms entered into the world’s most popular search engine.

QGIS on Google Trends

It’s also possible to compare search terms e.g. QGIS v’s MapInfo, QGIS v’s Microstation, QGIS v’s Geomedia and finally QGIS v’s ArcGIS.

The frequency of most GIS related search terms entered into Google, except “ArcGIS” and “QGIS”, have decreased considerably over the last 10 years. Only ArcGIS is entered into Google more often than QGIS nowadays, indeed ArcGIS has likely attained a monopoly market position. However, it is likely that QGIS will continue to gain ground on ArcGIS and desktop GIS may become a dichotomy of commercial and opensource software, a reaction to one companies’ market dominance.

Multithreaded Map Rendering in QGIS 2.4

The next release of QGIS will have multithreaded map rendering, a feature initially added to QGIS Enterprise in late 2013, a customised version of QGIS provided by the Swiss consultancy firm Sourcepole. The code providing multithreaded rendering is now part of the unstable development branch of QGIS, which is now undergoing testing. So what is multithreaded map rendering and does it mean for QGIS?

All modern desktop computers have multicore CPUs, with 4 to 8 processing cores on a single CPU die. In theory, multicore CPUs allow computer code to run in parallel on each processor core resulting in a considerable speed advantage. However, standard computer code does not take advantage of extra processing cores, so called single-threaded code uses one core at a time.

This is because multithreaded computer code has to be explicitly written and compiled in order to take full advantage of modern multicore CPUs. This is no easy task and multithreaded applications remain comparatively rare, generally limited to multimedia, games and computer graphics applications that require CPU intensive calculations.

Computer scientist Martin Dobias, who is adding multithreaded rendering to QGIS explained in a recent interview that the development version of QGIS was initially quite unstable, it often slowed down or even crashed because more than one processor core attempted to access the same data at the same time. In order for multithreaded rendering to work it was necessary to get the CPU cores to work cooperatively rather than competitively.

The current version of QGIS, 2.2 Valmiera, is single threaded. It uses one CPU core when redrawing the map window or when a menus are selected, it cannot multitask within its own application. This typically causes QGIS to become unresponsive while a map redraws when one zooms or pans. This is especially true for large data sets.

However, as seen in the demo video below, the development branch of QGIS 2.3 now has stable multithreaded map rendering. There is a considerable increase in map rendering speed but also significantly, the interface of QGIS remains fully responsive. Furthermore, the already impressive responsiveness will grow proportionate the number of CPUs and cores provided. Imagine QGIS 2.4 running on a modern dual CPU Xeon workstation, with up to 24 CPU cores and 48 processor threads. This is just a taste of what to expect in QGIS 2.4 which is due for release on the 20th of June.

QGIS 2.3 Multithread rendering from Oslandia on Vimeo.

Note: This article was edited to include the recent interview of Martin Dobias by Tim Sutton.