Exploring the world of free tools for GIS, GPS, Google Earth, neogeography, and more.
Download Squad posts about Maptales.com, a site that lets you upload geocoded photos with text (from a blog, mobile phone or Flickr) from a journey’s route to tell a story, and plots links to the journey photos in a Google Maps interface. The standard Google Maps navigation has been replaced by icons at the top (to the right of the search box), which take some getting used to. Not a lot of content right now, and you have to apply for an invitation key by email to use the site.
Portland State University’s Glaciers Online site has maps, photos and data for glaciers of the American West. Contents include:
The USGS GNIS is a gazetteer database of close to two million geographic landmarks in the United States (and, oddly enough, Antarctica as well). Types of landmarks include manmade (airports, hospitals, populated places, etc.) as well as natural (summits, arches, cliffs, etc.). There’s a direct interface to the GNIS at the USGS’s Board Of Geographic Names website that lets you search by feature name and get:
You can also download tab-delimited text files for individual states, or all states in one large file.
There’s another site with GNIS data, plus some extras. Wayhoo.com lets you search a copy of the GNIS database for US features, but has some additional options as well:
And Wayhoo requires no registration; you just need to have cookies enabled on your browser if you want to create a waypoint list.
Most free GIS programs have a measuring tool that lets you determine the distance between two or more points. But this distance is usually a flat, straight-line distance, and doesn’t take into account the additional distance you would travel if the terrain weren’t flat. If the terrain is steep or hilly, your 3D distance traveled is longer than that flat, straight-line distance.
MicroDEM has the capability to determine both the straight-line distance and distance over terrain for an arbitrary path. After loading in a digital elevation model (DEM), click on the Distance (stream selection) in the window’s toolbar:
Then draw the path on your DEM:
And MicroDEM brings up a window with the flat distance, and 3D distance over terrain:
If you have a map whose area is covered by the DEM, you can draw the path directly on the map:
MicroDEM links the map with the DEM, and will calculate the straight-line and 3D distances:
Lifehacker posts about MapMyRide.com, a new workout-oriented Google Maps site:
Free, but lots of ads (the price you pay …). Some of the features (e.g. Map Settings, Workout Calculator) don’t seem to work in the Firefox browser, but work in Internet Explorer (Windows).
ILWIS is a sophisticated GIS package that was released as free and open source software on Monday. While the open source version is available from 52North, there’s an add-on software package for ILWIS currently only available from the original ITC website. AHAS (AVHRR Hydrological Analysis System) works with ILWIS for analysis of data from the Advanced Very High Resolution Radiometer currently flying aboard many US and European satellites. Analysis products are biophysical (e.g. NDVI, Fractional Vegetation Cover, Crop Reflectance, etc.), climatic (Daily Radiation, Sunshine Fraction, Soil Heat Flux, etc.), and hydrological (Potential Evapotranspiration, Volumetric Soil Water Content, etc.). AHAS requires ILWIS to function properly, and will ask for the location of the ILWIS executable the first time it starts up (it first looks in C:\Program Files\ILWIS3.1\ for the Ilwis3.0.exe executable file).
Unfortunately, while AHAS is free, free multi-band AVHRR data is hard to find, especially recent data; if anyone knows of good free sources for this data, please post them in the comments section. You can buy AVHRR data directly from the USGS.
Juan Garcia writes to say that his Geo Utilities website has been updated. I’ve posted about this site before; it has a number of tools for Google Earth KML files, including:
Updates include modification of the algorithms to speed them up, and a download link to the source code, released under the GPL.
Back in 2005, EarthPlot software released several shareware tools for plotting data and creating graphic overlays in Google Earth. The most recent versions of their software are now available as freeware. If you’re interested in plotting spreadsheet data or creating annotated overlays in Google Earth, you should definitely check these out.
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