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Archive for November, 2009

Online Worldfile Calculator

Published by
Leszek Pawlowicz
 in GIS. Closed

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:

worldfilecalc

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.




gvSIG Version 1.9 Released

Published by
Leszek Pawlowicz
 in GIS. 1 Comment

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.




New Books For Geography Fans

Published by
Leszek Pawlowicz
 in cartography. 1 Comment
I’ve been a big fan of Frank Jacobs’ Strange Maps blog for several years now, and he’s now collected many of these maps and posts into a single fantastic volume called, appropriately, Strange Maps. Highly recommended for cartographers and map fans.
John Graham-Cumming’s compendium of places of interest for tech geeks and nerds (e.g. Bletchley Park, Chernobyl, the MIT Museum), but with a few points of interest for geogeeks as well (Greenwich Observatory, Gaithersburg International Latitude Observatory, the Arago Medallions that mark the French meridian).
The Natural World Of Saint Francis of Assisi describes how geography and its impact on the natural and cultural world of Umbria in Italy shaped the life and thinking of Saint Francis, one of the most influential figures in Roman Catholic history. Text by the award-winning natural history writer Susan Bean; great photography by National Geographic and Arizona Highways photographer Tom Bean.

“The beauty of Umbria that inspired Francis is still there today, as you will see in the evocative words of Susan Lamb and the remarkable photographs of Tom Bean. The rocks and landscapes, the winds and climate, the rivers, lakes and marshes, the plants and animals of Umbria and the neighboring parts of Italy are all brought to life in this book. ” – Dr. Walter Alvarez, Earth & Planetary Science Department, UC Berkeley




MapWindow GIS Updated To Version 4.7; Next-Gen Version 6 Beta Available

Published by
Leszek Pawlowicz
 in GIS and MapWindow. Closed

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.




Create KML Range Circles, Arrows And Wedges With An Excel Macro

Published by
Leszek Pawlowicz
 in Google Earth and KML. Closed

I’m currently running OpenOffice only, so I can’t try it out, but “Planeman” has created an Excel macro that will create KML range circles, arrows and wedges for a list of decimal latitude/longitude points. Should be able to create these for hundreds or even thousands of points simultaneously. Pictures are from Planeman’s description. Excel spreadsheet view:

mvsppi

And a view of the results from the sample data in Google Earth:

23wqxhc

Download the spreadsheet macro at this link; be sure to scroll down to the bottom to get the latest version. From the picture above, looks like additional features are coming soon.




kmlfactbook – The CIA World Factbook In Google Earth Format

Published by
Leszek Pawlowicz
 in data. Closed

The CIA World Factbook …

provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 266 world entities. Our Reference tab includes: maps of the major world regions, as well as Flags of the World, a Physical Map of the World, a Political Map of the World, and a Standard Time Zones of the World map.

In short, it’s the go-to source for current world demographic, economic, social and political data. David Tryse has taken data from the Factbook and created an online application, the kmlfactbook, that generates thematic maps in KML format for use with Google Earth. Select a dataset:

factdataset

Then choose a chart type, coloring scheme and other options:

charttype

2D charts are flat choropleths:

2dchoro

3D add scaling based on height:

3dchoro

And “Chart” creates a pie chart:

piechart

There’s a Google Earth plugin view that lets you preview the appearance, and when you’re happy, you can export a KMZ file. And you’re not limited to CIA World Factbook data; if you register on the site, you can upload your own data to convert it to a thematic KMZ file.

The one thing that seems to be missing is the ability to create a map legend to show what the color codes represent (or at least I couldn’t find it); you can click on placemark icons on each country to get the data, but it’s not the same. Hopefully, legends will be added soon.

Via Google Earth Blog.




Mashup And Map Demographic Statistics With DataMasher

Published by
Leszek Pawlowicz
 in data. 4 Comments

Take one of DataMasher’s 90-odd datasets (demographic, economic, energy, health, etc. data by US state), add/subtract/multiple/divide it by another dataset, and plot the results as a choropleth map (plus get the results in tabular form):

2009-10-31_204803

Mashups are posted publicly for comment and ratings. Results may be significant, or be totally devoid of meaning; YMMV. DataMasher makes no claims as to the statistical validity of any of the maps created. You can also select and plot individual datasets by themselves. There’s a short video on how the process currently works, and DataMasher promises more datasets and capabilities are coming.

Via Lifehacker.




Another Tool For Identifying Garmin Map Tiles

Published by
Leszek Pawlowicz
 in Garmin and GPX. 3 Comments

A few months ago, I covered GMapTool, a program that lets you identify the name and coverage area of a Garmin .img map file, whose only outward identifying info is a cryptic 8-digit filename that doesn’t reflect anything about its contents. Some people who have download the most recent version of GMapTool have reported getting virus warnings from their AV programs. I’ve checked GMapTool with MS Security Essentials (a terrific free AV program, BTW; unobtrusive, and doesn’t use a lot of system resources) and Avast antivirus, and neither one has spotted a problem – I suspect that the warnings are a false positive, though I can’t be sure.

Regardless, if you’re leery of using GMapTool because of the virus warnings, an alternative program is Mapsource Map Explorer. It doesn’t have the additional capabilities of GMapTool to split and combine .img map files, plus it only works on maps installed in MapSource (GMapTool can work on any .img file in a directory, not just those installed in MapSource). But if all you want is data characteristics for a set of installed map tiles, it does the job:

MapSourceExplorer

While the identifying map number may have less than 8 digits (e.g. “”162923” above), the .img filename for that map tile will have enough leading zeroes to pad out the name to 8 digits, i.e. “00162923.img”.




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