Monday, November 30, 2009
Using DeLorme Street Atlas USA
Saturday, October 31, 2009
Converting coordinates using online conversion utilities
If you don’t need to convert coordinates on a regular basis, you can save some hard drive space by using a Web-based coordinate conversion utility instead of installing GeoTrans. Most conversion sites are pretty straightforward to use; just enter the coordinate values that you want to convert and click a button. These sites are a few of the most popular:
- For simple datum, latitude and longitude, and UTM coordinate conversions: http://jeeep.com/details/coord
- For latitude and longitude, UTM, and Township and Range conversions:nwww.esg.montana.edu/gl
- For advanced online and standalone conversion tools, visit the U.S. National Geodetic Survey: www.ngs.noaa.gov/TOOLS
Understanding Graphical Locator
The Environmental Statistics Group at Montana State University hosts a very powerful online tool called the Graphical Locator. It’s a cross between a gazetteer and a coordinate utility converter. Some of its features are
- A map of the United States that shows coordinate information when you click a location. You can zoom in on regional and state maps. (The maps only show geographic features, not feature names.)
- Coordinate conversion utilities for latitude and longitude, UTM, and township, range, and section.
- Extensive information on selected locations, including latitude and longitude; township, range, and section; UTM; elevation; state and country; nearest named features and distances; and USGS 7.5 minute topographic map name.
To check out the Graphical Locator, visit www.esg.montana.edu/gl.
Using GeoTrans to Convert Coordinate
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Follow these steps to convert between coordinate systems with GeoTrans:
1. Select the map datum used with the coordinates from the drop-down
Datum list.
2. Select the coordinate system from the drop-down list below the datum.
Use Geodetic if you’re converting from latitude and longitude.
3. Enter the coordinates in the appropriate text boxes.
- If you’ve converting from latitude and longitude, enter the coordinates.
- If you’re converting from UTM, enter the Zone, Hemisphere, Northing, and Easting.
4. In the lower part of the window, select the datum and the coordinate system that you want to convert to.
5. Click the Convert Upper→Lower button.
The converted coordinates appear in the lower part of the window.
GeoTrans’ Help file covers these advanced features if you need them:
- Converting datums used in foreign countries
- Determining distance errors when converting between maps and scales
Tuesday, September 29, 2009
Advanced GNS Searches
For GNS advanced searches, you can enter an extensive list of feature types as part of your search criteria. These include oil pipelines, refugee camps, and vegetation types. Other options limit searches by the latitude and longitude boundaries of a rectangle, use special character sets from foreign languages, and use government and military codes as part of the search. If you want to run these advanced searches, the GNS Web site has links with explanations. If GNS finds records that match your search criteria, the features appear on a new page. A number of pieces of information are. For the average civilian user, the most useful data includes
- Name of the feature.
- Region of the world where the feature is located. Click the link to get an explanation of the abbreviation.
- Designation: The feature type (such as populated locality, farm, or reservoir). Click the link to get the definition of the abbreviation.
- Latitude and longitude coordinates.
- Area: Country and state or province information for the feature. Click the link for the meaning of the code.
Waypoint repositories
A number of Web sites provide waypoints that you can upload to your GPS receiver. (A waypoint is a set of coordinates for a location.) With these waypoint repositories, you can search a region or for a feature name for its waypoints in a database. If a waypoint has been logged in the site database, you can download the waypoint and then upload the coordinates to your GPS receiver. Some of the waypoint sites include
- http://wayhoo.com: This site converts GNIS and GNS feature information into waypoints. There are also coordinates for airports and a database where users can upload waypoints.
- www.travelbygps.com: This site holds a collection of waypoints for interesting places all over the world, including photos and descriptions. The site has an extensive collection of links to Web sites with special interest waypoints.
- www.trailregistry.com: This is a waypoint collection dedicated to hikers and backpackers.
- www.trailwaypoints.com: This is a GPS repository site that collects recreationoriented waypoints from all over the world.
Using the GEOnet Name Server (GNS)
The GEONet Name Server (GNS) searches for features around the world. GNS is located at http://earth-info.nima.mil/gns/html/index.html. The database contains over 3.5 million features and over 5 million place names for locations outside of the United States. The military relies on GNS for its operations, so the database is updated every other week. GNS is primarily designed for military use. Some of the search criteria and information in the database isn’t very useful to the average civilian. At best expect to find these types of information for a given feature:
- Country
- Type
- Latitude and longitude
- Go to the GNS Web site at http://earth-info.nima.mil/gns/html.
- Click the Access GNS link.
- Click the GNS Search link in the GNS Main Menu at the left of the page. You can enter search criteria by scrolling down the page.
- In the Name text box, enter the name of the feature you’re looking for. A drop-down list box to the right of the text box lets you narrow your search with these options:• Starts With • Is an Exact Match • Contains • Ends With
- If you know the country the feature is located in, select the country from the list.
- Click the Search Database button.
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