blankblank blank

Archive for October, 2008 Page 2 of 2

Next Entries »

Updates On The Garmin 1:24K US Topographic Map Front

Published by
Leszek Pawlowicz
 in Garmin and GPS. 1 Comment

Garmin continues to slowly add more and more states to their vector-based 1:24K US topographic map coverage. The latest release covers the central mountain West, Colorado and Utah, joining sets for Washington and Oregon as well as California and Nevada . These are in addition to their previous sets for US National Parks in the East, Central and West US; their websites says that maps for the rest of the US are “Coming Soon”. These Garmin 1:24K topo mapsets have some useful features, like elevation profiles, points of interest, routing on trails and dirt roads, and overlays for USGS topo quad and Township-Range-Section information. But at $100 list price ($80 street) for each set, it’s going to get pretty expensive to own even a small number of these. And since they’re being issued on microSD cards, they can only be used on one Garmin GPS unit at a time.

Fortunately, Dan Blomberg at the GPS File Depot, the MiscJunk website, and others continue to release their own versions of 1:24K topographic maps. While they don’t have all the fancy features of the Garmin sets, they’re free, based on the same US Government data as the Garmin maps, and can be uploaded to as many Garmin units as you like. Since my last update, Dan has released new 1:24K topo mapsets for New Mexico and Hawaii, and Idaho is coming soon; there’s also a new transparent overlay for Wyoming land usage/ownership. From the forum on his website, others following the process laid out in his tutorial on making Garmin topo maps are working on similar mapsets for Washington, Missouri and Florida as well. Dan has a list of links to all currently available free 1:24K Garmin topo mapsets at this link; currently, mapset links are listed for AZ, NM, CA, UT, CO, WY, MT, HI, MA, and MS. Maine is also available, but a link to that mapset is missing for now on Dan’s list.

And if you want actual USGS topo maps on your Garmin GPS unit, as well as other raster imagery, there are options …




A Basic Raster Image GeoMetaData Extractor/Viewer

Published by
Leszek Pawlowicz
 in coordinate conversion, GIS and software. 1 Comment

Many raster image formats commonly used in GIS applications have metadata embedded in them that georeferences the pixels (assigns them a coordinate location), and often includes other information like the coordinate system, origin, and datum. Some GIS programs will let you view some or all of this metadata, others won’t. I’ve written a simple GUI front-end program for the GDALInfo utility that will extract the metadata from a compatible image file, display it, and save it in a text file. Download the program folder here, and unzip it to your desired location; keep the executable and the GDAL subfolder in the same folder, otherwise the program won’t work. No installation required, just run the program. Choose the raster image file you want with the “Open File And Read MetaData” button:

Continue reading ‘A Basic Raster Image GeoMetaData Extractor/Viewer’




Displaying Datasets In The Google Earth Plugin With Earth Atlas

Published by
Leszek Pawlowicz
 in Google Earth and KML. Closed

Bjorn Sandvik, creator of the Thematic Mapping Engine for generating thematic prism/choropleth/bar/proportional symbol KMZ files, has just announced the first version of his Earth Atlas, an augmented viewer for the Google Earth plugin (Windows only for now). A tile on the right lets you choose one of 6 internal thematic demographic datasets to display in the globe, or two external ones (icecover and recent earthquakes). But you also have the option to enter the URL for multiple external KML or KMZ file, and have them added to the display as well. Here’s an external KML file from the Google LatLong blog showing photo overlays of flooding in the Kosi River region in India:

Google Earth plugin display with Earth Atlas

Note: you may have to manually scroll to the area covered by an overlay to see it.

In his announcement, Bjorn says “…to be continued!”, and based on his improvements to the Thematic Mapping Engine since its original release, that probably means a lot more capabilities will be available soon.




Another US Demographic Data Site

Published by
Leszek Pawlowicz
 in data. Closed

Mineful.com offers web survey, forms and marketing analytics software and services, but they’ve also just added a new section with free demographic data tabulation and visualization for the United States, broken down by state, county, zip code, and many demographic parameters (age, education, ethnicity, employment, marital status, etc.).

9-29-2008-8.29.11 PM

Unfortunately, the data isn’t downloadable. But for a quick overview of basic demographic data, it does the job. Jaime Brugueras of Mineful, who sent me the link, says that they’re working on additional capabilities for the site like search, radius profile, and more geography types.




Update To Google Earth Position Application

Published by
Leszek Pawlowicz
 in Google Earth. Closed

Last week, I posted on David Tryse’s Google Earth Position application for Windows, which can capture and save the geographic position in the center of the Google Earth view window. The biggest issue with the application is that it was difficult to figure out how to place a geographical object exactly at the center of the Google Earth window, since there’s no crosshair or marker in the application to indicate where it is. I linked to a KMZ file that places a crosshair at the Google Earth screen center, but that’s no longer necessary. The latest version of Google Earth Position now has the option to add such a crosshair to the screen. After starting the program, just right-click on it, and select the Show Crosshair option:

9-29-2008-8.03.14 PM

This will open up a crosshair screen overlay in Google Earth, at the center of the screen; this is the position displayed/captured in the Google Earth Position app:

9-29-2008-8.05.01 PM

Non-Windows users can use the KML link described in this post, or this one suggested by Maarten in comments (though I’ve had problems getting  it to work).




Next Entries »