I use to recommend the TatukGIS Viewer as a good free program for merging raster imagery and export it in georeferenced full resolution, but as last week’s post indicated, the latest version of it drops this functionality. Someone asked me for a recommended free alternative, and for now I’d pick MicroDEM for that. It does have some limitations:
Archive for the 'GIS' Category Page 3 of 20
The recent earthquake in Haiti reminds me to give a plug to MapAction, a non-profit, volunteer humanitarian organization that provides rapid mapping and GIS support to humanitarian relief efforts after major disasters. Less than 12 hours after the Haiti earthquake, they had a four-man team on the ground to provide mapping support to relief agencies and workers. Check out their 28 deployments to date on this page, and if you’d like to help, there’s a donations page here.
Addendum: James Fee has a long list of Haiti-related Geospatial Community Links, including data sources and relief agencies, plus a link to GISCorps, an organization similar to MapAction.
A few years ago, I had several posts on the TatukGIS Viewer, a free program for viewing vector and raster GIS data. IMO the most valuable feature of this program was the ability to export georeferenced raster imagery of the view, with a great deal of flexibility in the resolution of the final output. Recently, TatukGIS announced a major upgrade to version 2.0 of the Viewer, the main improvement being on-the-fly reprojection of raster/vector data; previously, all the data had to be in the same coordinate system. Unfortunately, after trying it out, I discovered that they have removed the raster export function completely; it’s only available in their GIS editor, which costs $350. It’s still not a bad GIS viewer, but with the loss of this export function, I’d have to say you’d be better off learning how to use one of the free GIS viewers/editors that offer either on-the-fly reprojection, raster export, or both (e.g. gvSIG, qGIS, MapWindow, and many more – check my Big List Of Free GIS Programs posts for more). Plus, with these free/open-source options, you won’t have to worry about features being removed arbitrarily.
If you still want to try the new version of TatukGIS Viewer, make sure not to select the option that uninstalls the old version, like I did. Fortunately I had an older installer archived, as TatukGIS has removed all links to older versions.
Over a year ago, I posted about GISVM, a Linux GIS workstation in a virtual package that could be run in free VM software like VMWare Player or Virtual Box. You can now try out a more recent release of this package (christened Arramagong, and distributed at the 2009 FOSS4G conference in Australia) in a Java-based virtual machine viewer at the click2try website. You need to register (for free) to save data and settings, but you can try it out without registration. You’ll definitely need a broadband connection to run it, and there’s a connection test to make sure your network link is up to it. Once running, display refresh speed is adequate enough to load up apps and try them out. Wouldn’t want to run the apps full-time on this service, but that’s certainly not the intention for this package – it’s just to show off what’s available in the distribution. If you like it, you can always download the 1 GB+ full distribution and a free virtual machine environment, and run it at acceptable speed on your own computer.
In addition to the apps you see listed above, it also has qGIS, uDig, RGeo, openJump, and MapTiler
A Practical Guide To Geostatistical Mapping by Tomislav Hengl
Geostatistical mapping can be defined as analytical production of maps by using field observations, auxiliary information and a computer program that generates predictions. The purpose of this guide is to assist you in producing quality maps by using fully-operational open source software packages: R+gstat/geoR and SAGA GIS. Materials presented in this book have been used for the five-day advanced training course "GEOSTAT: spatio-temporal data analysis with R+SAGA+Google Earth" that is periodically organized by the author and collaborators. This is an open access publication!
In addition to a free downloadable PDF copy of the book, you can:
- Download the datasets used in the text; they are very heavily oriented towards environmental issues
- Buy a hardcopy of the text from lulu.com for $12.78
- Read the chapters online in a scribd interface, and enter comments and suggestions for improvements
Geospatial Analysis: A Comprehensive Guide To Principles, Techniques And Software Tools by de Smith, Goodchild and Longley
Topics covered:
- Geospatial analysis concepts
- Core components of geospatial analysis, including distance and directional analysis, geometrical processing, map algebra, and grid models
- Exploratory Spatial Data Analysis (ESDA) and spatial statistics, including spatial autocorrelation and spatial regression
- Surface analysis, including surface form analysis, gridding and interpolation methods
- Network and locational analysis, including shortest path calculation, travelling salesman problems, facility location and arc routing
- Geocomputational methods, including agent-based modeling, artificial neural networks and evolutionary computing
Full text is available online, including diagrams; text is organized by chapter, searchable, and includes Google Translate buttons in 10 different languages. A free PDF is available with purchase of the book.
If you have a scanned map image, and know the geographic coordinates of the upper left and lower right corner, plus the image dimensions in pixels, the online World File Calculator will generate a worldfile for that image that you can use to load it into a GIS editor or image viewer:
Copy and paste the text in the “worldfile” section into a text editor, then save it with the appropriate file extension as described above on the right.
One major caveat: you need to make sure the coordinate system you use matches the projection of the map image, e.g. UTM coordinates for a UTM projection; geographic coordinates (lat/long) for a geographic projection (Plate Carree), etc.. If you use the wrong coordinate system to generate the worldfile, that’s likely to introduce large errors into your calibration.
It’s been over two years since the last full stable release of the free Java-based GIS gvSIG (runs on Window, Mac, and Linux). I thought that version 2.0 would be out soon, but got fooled – the new version is 1.9. This is a huge enhancement, with major functionality improvements in:
- Raster analysis and remote sensing
- Symbology and labeling
- Topology
- Network analysis
- Vector editing and manipulation
- Export to the Windows Mobile version of gvSIG
- And more; see the New Features log for more info
One minor problem with gvSIG for English users has been translation issues with the installation program and user interface (gvSIG originates in Spain, from the Valencian Regional Council for Infrastructures and Transportation (CIT)). Oxford Archaeology Digital created a modified version of gvSIG 1.1.2 (the last stable release) which cleaned up some of these language issues, and the web page indicates that they’re working on a comparable English-oriented installer and interface for version1.9. I’ll keep a watch on that page, and post when the new version is ready.
It’s been over a year since I last posted about a version update (4.5) for the free Windows GIS MapWindow (topic of multiple previous posts). Just noticed that version 4.7 was released just a bit more than a week ago. Improvements since 4.5 include:
- Stability improvements, particularly when dealing with large numbers of shapes in shapefiles
- TauDEM/Automatic Watershed Delineation Help Files
- Progress indicator improvements in many plug-ins
- Unit conversions available for more standard units and more accurate
- New image properties in MapWindow (Use Histogram, Allow Hillshade, Buffersize, Image Color Scheme, Set to Grey
- Zooming with mouse wheel
- Updated GDAL projection library
- Added GEOS shape functions (Contains, Crosses, Touches, Intersects, Overlaps, etc.)
- New printing plug-in
- New image properties (Use Histogram, Allow Hillshade, Buffersize, Image Color Scheme, Set to Grey)
- Bug fixes and speed improvements
- Improved documentation
And if you want to look at the future of MapWindow, there’s a Codeplex development page for MapWindow 6 where you can download the latest beta (which looks to be in a pretty usable state) and fairly extensive documentation. What’s the difference between MapWindow 4.x and 6? From the Forward:
The MapWindow 6 platform is a major step forward. It is completely .NET based, has no COM or ActiveX references, and is totally built around the idea of interfaces and components. If you are a developer you can rebuild the MapWindow 6 desktop application in about 10 minutes by simply assembling the correct components and hitting the “compile” button. If you are an end user, you will find significantly improved symbology and printing capabilities and a new modeling toolkit and environment that are just plain awesome.
First stable release of MapWindow 6 is scheduled for the first half of 2010, hopefully at the 1st International MapWindow Users And Developers Conference.
