Via Vector One, I discovered Kelso’s Corner, a blog by an award-winning cartographer for the Washington Post; it’s been added to my blogroll at left. In turn, that blog pointed me to Color Oracle, a free Java tool (Windows, Linux and Mac) for evaluating the effects of several kinds of color blindness. I was surprised to learn that 8% of the male population suffers from some variety of color blindness (that’s about 1 out 12), so keeping their limitations in mind is important. Run the program, and it lets you choose between the three most common kinds of color-blindness: Deuteronapia (most common), Protanopia (rare) and Tritanopia (very rare). It changes the coloring of the entire monitor to reflect what it would look like if you had that specific kind of color blindness, and plasters a big label on the screen to let you know which kind of color blindness is being simulated. Click anywhere on the screen to return to normal color. The program also lets you get a screen capture of the color-blind view.
Continue reading ‘Evaluating Map Graphics For Color-Blind Viewers’
I’ve covered the free GeoPDF plugin for Adobe Acrobat and Reader before, but the latest version adds a lot of new features:
- Create a point on the map, then open and view the corresponding point on Google Maps
- A lot more coordinate systems supported, including MGRS, Lambert Conformal Conic, Mercator, etc.
- Import and display shapefiles, re-projecting them on-the-fly
- Import Google Earth KML/KMZ data; also CSV and GPX files
- Annotate points with “sticky notes”, or with a GeoStamp symbol in various categories (incidents, infrastructure, operations)
- Draw rectangles, polylines and polygons, and annotate them
- Export annotated and imported data in shapefile format (automatically split into points, lines (arcs) and polygons)
- Export annotated and imported data in KML format for use in Google Earth (another way to convert shapefiles to KML format)
One capability that’s still missing is the ability to export the view in georeferenced raster format, like GeoTiff; hope that’s coming soon.
The TerraGo Technologies tutorials page has a video tutorial on GeoPDF, and brief written tutorial with sample data for you to play around with. You can also download free USGS topo maps in GeoPDF format from the USGS Store’s Map Locater and Downloader. While these are still mostly in raster format, the next generation of USGS topo maps will come in vector GeoPDF format, letting you select from up to 37 different data layers.
Via Directions Magazine.
3/6/2010: The newer Colorado/Oregon/Dakota GPS units can store and display more data; see this Oregon Wiki page for more information. So you can now incorporate far more shapefile attribute data into the POI information section than with earlier GPS models.
Garmin POIs (Points of Interest) datafiles can contain up to two lines of text data for the name, and up to four lines of data for the description, far more than the more limited space for the same data in a GPS waypoint. This gives you enough room to include at least some of a point shapefile’s tabular attribute data for a location, and take it into the field with you for reference. And while there’s typically a limit of 500 to 1000 waypoints on many Garmin GPS units, you can put tens of thousands of locations into a POI file, along with that associated data. Here’s one way to create Garmin POI files from a point shapefile, though you could use comparable tabular data as well.
Continue reading ‘Creating A Garmin GPS Points Of Interest (POI) File From A Point Shapefile’
Google has just announced the addition of topographic contour lines to their Terrain view in Google Maps. It’s for the entire world, so I suspect they’re using SRTM 90-meter resolution data; not ideal, but not bad, either. Here’s Popocatepetl, just SE of Ciudad de Mexico:
You have to zoom in to at least the 1-mile / 2 km range for the contours to appear.
Now that TIGER has officially moved to the shapefile format, the only TIGER data left in the previous format available on the Census website is the 2006 Second Edition data, and that’s likely to disappear at some point in the future. GIS@Vassar links to an announcement at ICPSR that they have TIGER data in the original format from 1990-2006 archived for download here. Convert it to shapefile format with the free version of tgr2shp, or to KML with tgr2kml.
Creating custom icons for Garmin POI files is similar to, but actually easier than, creating them for custom waypoints. I’ve covered the basic details of creating custom waypoint icons in two previous posts (part one and part two), and refer you to those for the general process. But the graphic format requirements are somewhat relaxed for custom POI icons compared to custom waypoint icons:
Continue reading ‘Creating Custom Icons For Garmin Points Of Interest (POI)’
