In an earlier post, I covered Terrain Bender, a program that lets you create varying-angle terrain views from digital elevation models (DEMs), with optional overlay imagery, analogous to the view you get from the window of an airplane:
Archive for February, 2010
SlashGeo posts about the Illustrated Guide To Non-Profit GIS And Online Mapping from MapTogether, a website from the Community Cartography Project. It’s a really good, basic introduction to the concepts behind GIS and digital mapping, and examples of their use. The whole site is worth poking around if you’re interested in the topic, especially the blog posts. If you’re interested in moving forward from this guide, you can try MapAction’s Field Guide To Humanitarian Mapping, and also the great tutorial series from the Department of Land Affairs, Eastern Cape, South Africa called introducing GIS.
Standard terrain visualization programs like MicroDEM or 3DEM typically give you the option of viewing terrain either from top down:
Or from an oblique angle, looking in one direction:
Continue reading ‘Varying-Angle Terrain Views With Terrain Bender’
With 895,000 records and 1,115,000 names, the Getty Thesaurus Of Geographic Names Online lets you look up position and hierarchical data for geographic features around the world:
The position data is described as “approximate and … intended for reference (“finding purposes”) only”; a few test cases showed that the positions ranged from spot-on to over a mile off for locations in the US. Lookup can be by name only, or limited by type of geographic location and nation; Boolean and wild-card operators are supported.
Quite a while back, I did a post on Metacarta Labs’ Map Rectifier, an online application that let you upload a raster image, use online mapping services to georeference it, then export it in GeoTiff or WMS format. Map Warper is an extension of this online rectifier, with some similarities in the basic interface. But Map Warper adds some useful extra features:
- Your own personal account, where you can add and manage map images, including map descriptions and tags.
- The option to make your map private (Map Rectifier requires all maps to be public).
- You can crop the map to a user-specified polygon shape.
- You can preview the rectified image as an overlay on top of the reference image.
- In addition to GeoTiff and standard WMS export, you can also export it in KML format as an image overlay, or as a WMS link that can be used in the JOSM OpenStreetMap editor. You can also open a KML file directly in a Google Maps interface.
- On the downside, there’s no Google Maps layers to use for calibration/rectification, only OpenMaps data and Landsat data; the author indicates that he may add Google Satellite imagery at some point in the future, depending on the licensing limitations.
Maps are exported in geographic projection (lat/long), WGS84 datum, making them perfect for use with programs that generate raster maps for GPS units (e.g. TritonRMP Helper for Magellan Triton units, G-Raster for supported Garmin units).
The same map rectification engine is used by the New York Public Library’s Map Rectifier tool, a crowd-sourcing georeferencing tool. You can select from already georeferenced historic maps and export them in GeoTiff format, or select an uncalibrated map and georeference it yourself. Same export functions, although the KML image overlay in Google Earth is a network link, and the Google Maps view doesn’t work very well. Since the MapWarper application is open-source, you could use it to create your own crowd-sourcing website, like the NYPL site, to aid in georeferencing a large number of raster map images.
Google Maps MyMaps feature lets you create and save simple maps (lines and points), and share them with the world. But the sharing is done through a network link, not through a stand-alone KML file, and you can’t save the data directly to your computer. The GMaps tips website offers a simple way to save a stand-alone KML file of your MyMaps map:
1. Create the map.
2. Right-click on the “View In Google Earth” link, and copy the link address; paste it into a text editor:
http://maps.google.com/maps/ms?ie=UTF8&hl=en&vps=1&jsv=206b&msa=0&output=nl&msid=106563725672137103118.00047ef5a12bca4f8b665
3. Change “output=nl” to “output=kml”
http://maps.google.com/maps/ms?ie=UTF8&hl=en&vps=1&jsv=206b&msa=0&output=kml&msid=106563725672137103118.00047ef5a12bca4f8b665
4. Paste the modified link address into your browser’s address bar, and go to it; depending on how your browser preferences are set, you’ll either save the KML file for your map to your standard download directory, or it will open in Google Earth. In the latter case, right-click on the KML entry in the View pane at left, select “Save As”, and choose a name and location to save it in.
Useful if you’re stuck using Google MyMaps, maybe because of its collaboration options. If you don’t need to collaborate, Scribblemaps and Scribblemaps Pro offer direct KML export and have a much greater selection of drawing tools than Google MyMaps.
12/28/2010: Original method doesn’t work anymore, as the “View In Google Earth” link shows up very briefly, then disappears in favor of viewing the data in the Google Earth plugin in your browser. But you can still get it to work with a slight revision. Instead of right-clicking on the “View In Google Earth” link, do that on the “Link” in the upper-right-hand corner, then copy and paste that into a text editor. Then insert “&output=kml” (no quotes) before “&msid” in the link text. Copy and paste that modified link into your browser, and it will work as advertised.
Claude Henri-Meledo writes to tell me about BeGraphic Lite, a free data visualization tool for Microsoft Excel. I don’t currently have easy access to Microsoft Excel (I’m working in OpenOffice exclusively), so I can’t try it out, but it looks interesting. It apparently does a wide variation of data graphics, not just maps; these include:
cascade chart / waterfall chart, marimekko / mekko chart, sankey diagram, dynamic diagram, pivot diagram, powerpivot charts, pivot chart, ishikawa cause-effect diagram, BCG matrix, ADL matrix, McKinsey 7S, RB profiler, DuPont chart, choropleth map, swot analysis model, vector glyph, business chart, business graph, business graphics, professional excel chart, mini-graphs, micro-charts, sparkline for excel, excel gauges, strategic maps, strategy map, dashboard software, moving bubble, motion chart, trend analyzer, scada system, control room, make a custom map in Excel, thematic map in PowerPoint, dynamic sales territories, mapping tool, geographical information system in excel2010, choropleth map, and any innovative charts…
A few sample map screenshots from the website:
BeGraphic LIte works with the free vector graphic map data available at d-maps.com, which now has 7500 maps available (up from 4000 when I posted about the site in August 2009). Edit: You need to download the files in WMF format. There’s a Pro version of BeGraphic in the works for later this year, but the Lite version will still be free and available.
The GE Coords program simplifies the job of grabbing coordinates for a point in Google Earth, and putting them into your clipboard, from where you can paste them into the application of your choice. Not terribly complicated to use (and the website has more complete instructions if you need them):
1. Install the program (you’ll find it in the “Thots Utilities” folder)
2. Fire up Google Earth, press the yellow pushpin icon on the toolbar, and drag it to your desired location:
3. After closing the placemark properties box, right-click on the pushpin and select “Copy” from the drop-down; this will copy the full KML code for the placemark into the clipboard
4. Run the GE Coords program; it parses the KML code, extracts the position, and copies the coordinates into the clipboard. You’ll hear a beep when it’s done. DM is the default format:
N 35° 01.640 W 111° 01.364
But running the program without any placemark code in the clipboard brings up the option to “Setup” the desired default coordinate format:
