Please visit our new site, GPSTracklog.com.
Please visit our new site, GPSTracklog.com.
A decade ago, B.G. (before GPS, at least for me), I lived in a part of the Southern Appalachians surrounded by National Forests. I loved exploring the area by mountain bike, and while I wasn’t yet into GPS, my love of maps was already deeply ingrained.
Not yet to the point of filling my hard drive with maps, I instead had a wall full of USGS topo quads, the collars cut from them, detailing a mosaic of the regional landscape. But one day my good friend, fellow biker and map junky, Sparrel, told me about U.S. Forest Service (USFS) maps.
The image above shows a portion of a map near my new neighboorhood, the Mendocino National Forest. Note that the map is brown and white, even though this is a heavily forested region. Unlike USGS quads, these maps don’t show vegetation. What you gain though, are Forest Service road and trail numbers, gate locations, and more legible boundaries. Sometimes these quads are even more up to date than the standard USGS 7.5’ series. Once I discovered these, I was well on my way to acquiring a second set of topo maps for the region!
I recently discovered a great portal for USFS maps and vector data. I stumbled across this via the OziExplorer message forum. They don’t have all the USFS topos, but you might want to check it out to see what they have for your favorite stomping grounds.
Continue reading "Source for U.S. Forest Service topo maps and vector files" »
I've written before about all the wonderful and free GIS data available online. Well, I came across a great new blog the other day, the Free GIS Data GeoBlog. Much of this information is available in other places, such as this excellent resource. Still, the Free GIS Data GeoBlog looks promising. I am especially excited by the fact that they are posting international data. And remember, if you aren't a GIS professional with access to ArcView, OziExplorer is a great package that allows you to use your GPS and use GIS data.
Via Cartography.
The Map Room recently covered the National Agricultural Imagery Program (NAIP). Now don't be confused by the Agriculture part of the name, because the NAIP is of value to a much broader audience. NAIP offers very recent, natural-color aerial imagery of almost the entire U.S., at a relatively high resolution. Full county mosaics are $50. For my county, there is a 2006 image with a resolution of 2 meters/pixel, and a 2005 image at 1 meter/pixel. The image at left, of the Big River estuary and Mendocino, CA, is supposed to be 2 meter resolution. The resolution doesn't look quite that sharp to me, but nevertheless, I can make out recent changes in logging roads in the area I frequent for mountain bike rides. The image to the right below, shows a 3-D view with waypoints, that I created using OziExplorer.
The color county mosaics are in MrSID format. You can use OziExplorer to work with these files, and the NAIP website lists several viewers. Quarter quadrangles are available in GeoTIFF format. Here's the latest (2005) aerial photo coverage map for color county mosaics.
Unfortunately, we're dealing with the feds here, so ordering is a pain and delivery is slow.
There’s lots to cover this week, so let’s get right to it:
GPS Hardware
GPS Software / resources
GPS in the news
Geo-Google
Technorati tags: GPS
I have lots of links for you in this week's roundup, so let’s get right to it:
Garmin
GPS in your life
Historic maps
All the rest
Technorati tags: GPS
Odds and ends from the blogosphere and beyond:
Technorati tags: GPS
There is a wealth of Geographic Information System (GIS) data available on the web — everything from public land boundaries to international contour files. It is amazing what you can find. A few examples:
GIS files are most commonly found in either .shp (shapefiles) or .e00 formats. Unfortunately, few consumer-level GPS mapping programs allow you to utilize GIS files. OziExplorer is my favorite program for working with GIS files. Using it, you can convert these files to tracks and points, and even display this info on your GPS. Another program, ArcExplorer, is a free GIS viewer, but it lacks GPS compatibility. The image, to the right above, was captured from OziExplorer. It shows public land boundaries in green and private timberlands in yellow, superimposed on a color aerial photo.
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