Locate and Download free USGS GeoPDF maps using the Map Downloader
Written by Glenn Letham
10 May 2007
The USGS has a number of clever ways for users to search, navigate, purchase, and download maps and data... the Map Locator is the latest addition and it's pretty darned sweet! Using a Google Maps UI, visitors search the map by entering a search string, zoom into an area of interest, or select a point on the map for relevant hits. Once you've explored, you then have access to free data served up as GeoPDFs... read on for more about working with these GeoPDF data products... best of all this is all FREE!
As a sample, I search using the term "Fort Collins, CO" - optionally, I can elect to view results that are either 7.5 or 15 minute (zoom in tighter for this one), or for 30 minute datasets. Clicking on the ever-familiar Google map balloon icon invokes a pop-up window that displays all the available map products. In my case I see a 7.5x7.5 quadrangle, a 30x60 sheet, and a 1x2 from a nearby area. Optionally, I can then order the data or even cooler... download the file directly (so why the heck would anyone actually go and pay to download this data from a datadepot or other "commercial" provider of these free data?). Clicking the "all maps for this location" option brings up a HUGE list of maps and data products for this region (shaded relief, topos, elevation maps, and other scientific data products). Clicking the "Download" link causes just that, I download a 5 MB file containing the USGS topo file. The download was not terribly fast, however, I did get 105 kb p/sec download... not bad. Compare this to other USGS data providers that will throttle-back their downloads to about 5 or 10 KB a second for a free download - you may as well go grab a coffee and the newspaper while doing that ;0)
The Map Locator with the familiar Google maps UI
Searching for a map - search term "Fort Collins, CO"
Clicking the Balloon provides order and download options
Clicking the "all maps for this location" option brings up a HUGE list of maps
So what do I get with this free download? I get a nice GeoPDF file - grabbing the free GeoPDF plug-in will enable me to use this file created with the very cool MAP2PDF to its full extent, although grabbing the plug-in is not required it's free so why wouldn't you download it?? See http://www.terragotech.com/solutions/map2pdf-reader.html
The GeoPDF format USGS topo sheet
Downloading the GeoPDF Toolbar
Once you have your free file and you have the GeoPDF toolbar installed then your well on your way to having some fun with your topo sheet. Open the DRG in the familiar PDF environment but now you have access to loads of other options and mapping functionality. Things you can do include panning, and zooming, measure length or areas, place pointers by inserting a lat/long coordinate, start a GPS track, or something very cool, Mapit on Google Maps (this brings up a new explorer window and calls gmaps centering you on the area of interest... cool! Now you can view the topo along side the street map or imagery.
Added functionality available thanks to the GeoPDF Toolbar
Measuring length or area using the topo sheet as a GeoPDF
The MapIt on Google Maps utility is pretty slick!
Want to do much more using your GeoPDF? Check out the GeoPDF Extensions like GeoMark, enabling you to have redlining functionality, Map Assembler for creating map tiles, GeoImage Import to enable you to import geolocated imagery, or GeoPDF to GeoTIFF... this ones way cool as now you can convert your FREE GeoPDF Topo sheet into TIFF format for use in virtually an GIS platform around... NICE! See more about the available extensions at http://www.terragotech.com/solutions/geopdfext.htm - as a teaser, the crew has a web service extension coming soon - I can't wait to see that one!
This causes a new explorer window to open up, centering you on the area of interest in Google Maps
More About the GeoPDF Toolbar (supplied by TerraGo) GeoPDF Toolbar allows users to view multiple coordinate display, re-project to most coordinate systems, measure distance and bearing, zoom to any coordinate, and connect to GPS and track. After installing GeoPDF Toolbar you will have a new toolbar within Reader that will be active when viewing a GeoPDF (geospatially enabled PDF document). This toolbar will allow you to view coordinates, reproject user coordinates, measure distance and area, zoom to a coordinate, Google Map a specific coordinate and connect to a GPS device. Additionally, layers can be turned on and off, associated attributes can be viewed by selecting the Object Data Tool and clicking on specific objects in the map and finally, the map can be searched by selecting the Adobe Search Binoculars and typing in keywords. Note that the Search feature will query both data on the map and embedded data.
HxGN Live - The Hexagon Global Network - Learn about surveying, mapping, laser scanning and geospatial solutions from Leica Geosystems. June 3-6, 2013, Las Vegas, Nevada
Join us at GIS for Government 2013 taking place June 24-26, 2013 in the Washington, DC Metro Area to find out everything you need to know about GIS. Click here for more information