- In addition to their original imagery, the Map Of The World - Shaded Relief site has added the Natural Earth landcover and shaded relief imagery of Tom Patterson.
- Hans writes to say that his World: Relief Map And Geolocations website has moved to a new URL with a new name, SRTM Relief Layers For Google Maps. New features include layers on the shaded relief map for administrative boundaries, water bodies, transportation (road and rail), and SRTM tile names (layer feature may only work in Firefox); links to the tile imagery used for the map; and a tutorial on how to add relief imagery to your own Google Map display.
Archive for August, 2007 Page 2 of 5
Newer Garmin GPS units support the upload of sets of POIs, containing both position data and descriptions of the Points Of Interest. The KMLCSV Converter is a Java application that lets you convert placemarks created in Google Earth and saved as a KML file into a CSV (Comma-Separated Values) file compatible with Garmin’s POI Loader; this CSV would also be compatible with most spreadsheet programs as well. The process is straightforward:
1. Create placemarks in Google Earth using the “Add Placemark” tool, search, or other means.
2. Add a description to the placemark.
3. Drag all the placemarks you want to save into a single folder.
4. Save the folder as a KML file
5. Convert it to a CSV file with the KMLCSV Converter Program (screenshot from website)
6. Upload the CSV POI file to your Garmin with the POI Loader program, or into your spreadsheet as a standard CSV file.
There’s a short PDF tutorial file that covers these steps quite clearly with screenshots.
You can also convert CSV files, either POI files or spreadsheet files created by yourself or someone else, into KML files for viewing in Google Earth; a search for “Garmin POI” files on the web will bring up links to many sources, both free and paid. But I prefer the program csv2kml for that purpose.
In addition to a subscription service with more data, features and capabilities, Social Explorer offers an easy-to-use demographic data mapping and download service, with US Census data from 1940-2000. Select from population, age,sex, marital status, race, education, housing, industry and many more. Each category has its own set of subcategories to choose from for mapping, e.g. for population you can plot population density, % urban, % rural, % inside urbanized areas and % inside urbanized clusters.
The Maps Social Explorer opens up a Flash (?) interface, with demographic parameters selectable using the drop-downs at the upper right. Mapping can be done by census tract (as above), or by 2000 Congressional District boundaries. You can zoom into any area of the US:
Select Print, and the map and legend will open up as images in a separate window, so that you can save or print them. Select Report, and you can view tabular data for a selectable area of the visible map, and download it in Excel format.
With the Reports Social Explorer, view similar demographic data for the entire US, state, county or census tract in tabular format on-screen, and download it in Excel format.
A team of scientists at MIT have developed a software tool designed to analyze “visual clutter” in graphic images. The example given in the press release compares the tool’s analysis of visual clutter in maps of the US and San Francisco with that of 20 people, and they found a good correlation between human and software clutter metrics. The software is free for download and use, but requires MATLAB to run (which I don’t have, so I can’t test it out).
G.Projector, posted about earlier, only produces flat, non-interactive map projection images. map projection is a stand-alone map projection viewing program with interactive capabilities. It was written to demonstrate a concept called the “floating ring”, where you can move a circular figure about a globe and watch the change in its distortion in a map projection viewer - sort of a souped-up interactive version of Tissot’s Indicatrix. The program is available for Windows, Solaris, and IRIX; be sure to download the coastline data file as well, and put it in the same directory as the executable.
Continue reading ‘Stand-Alone Map Projector Viewers II - map projection’
Many GPS-related programs require an NMEA connection to your GPS through a serial port. But many new computers don’t include a serial port anymore, while many new GPS models, particularly Garmin, only have a proprietary USB interface and not a serial NMEA interface. For computers that don’t have a serial port, you can always buy a USB to serial converter like those from Keyspan. And for Garmin USB-only GPS units, there’s a program called GPSGate from Franson that converts the USB connection to multiple virtual serial NMEA ports, $10-30 depending on how many ports you need. Garmin offers a similar program for free called “Spanner” for their GPS 18 model, a USB receiver/antenna that’s designed to plug in to a notebook’s USB port and interface with programs running on it. What Garmin doesn’t say is that “Spanner” will also work with some, albeit not all, of its other GPS receiver units; you’ll have to experiment to see if it works with your model. And even if your Garmin has both serial and USB interfaces, like my Garmin 60Cx, using this program can save you the expense of a GPS-to-serial cable, a USB to serial converter if your computer doesn’t have a serial port, or both.
Download the Spanner program from the Garmin website, and install it. The program has only one configuration window:
You need to have your GPS turned on, connected to your computer via USB, and using the Garmin protocol; if any of these isn’t true when you start Spanner, make it so, then click “Find GPS”. At the bottom, use the “Add” button to add a virtual serial port to your computer for use by your software as an NMEA connection. Make sure you choose a number for your COM port that doesn’t conflict with any your computer currently has. I believe that Windows can handle COM1 through COM 255, but keep in mind some software programs won’t support ports higher than COM8, or even COM4.
I’ve had two programs running simultaneously, each one getting NMEA data from a different COM port, and given that COM ports are pretty slow, I’d guess that you could add a few more without putting a serious strain on your computer’s resources.
Earlier posts in this series covered online map projection viewers, the best of which is the Brazilian Map Projections Java app. As an interactive learning tool, that one is hard to beat, and the stand-alone map projection viewers don’t match up to it in that regard. But each of the stand-alone viewers I’ve found has useful features that aren’t present in the online map projection viewers.
The first one I’ve looked at G.Projector, produced by NASA’s Goddard Institute For Space Studies (GISS). It’s a Java app, with specific versions available for Windows, Mac, and Linux. Download the file, and unzip the contents into their own folder; in the case of the Windows version, there’s an executable file called G.Projector.exe that starts up the program.
Continue reading ‘Stand-Alone Map Projection Viewers I - G.Projector’
Ogle Earth posts on NAC Earth, a Google-Earth addon that lets you navigate to a Natural Area Coding (NAC) location. Never heard of NAC? Neither had I until this post. It’s apparently a proprietary universal address system that can assign a sequence of up to 8 letters and digits to any geographic location or landmark; Stefan at Ogle Earth describes it as the geographic equivalent of tinyurl. He also doesn’t see much need for it, and truthfully neither do I - if you want to describe a location by a semi-cryptic series of letters and numbers, you can always use MGRS. Given that the system has been around now for five years without picking up any traction, I’m guessing others feel the same way.
Need to convert a set of geographic coordinates to an NAC code? Try Barry Hunter’s online coordinate converter. The NACGeo site also has some free online services for looking up and plotting NAC locations.
