They'll often know their own latitude and longitude. *Use a Global Positioning System (GPS) receiver. Many outdoor, sporting-goods and camping stores also sell USGS 7.5-minute maps. Contact USGS for information about pricing and how to order topo maps. You'll find this information in the map index for your area.
To obtain the 7.5-minute map that covers your location, you need to determine the reference code, map name and state.
For finding your grid square, use only the latitude and longitude system.Īn online topo map is available at the U.S. The other system is the universal transverse mercator (UTM) system that consists of squares 1 kilometer on a side. One system uses latitude and longitude- this is what we want. These maps usually include two coordinate systems to define location. Most of these are at a scale of 1:24,000 (1 inch = 24,000 inches, or 2,000 feet). The most useful series of maps for finding latitude and longitude are the 7.5-minute maps, each of which covers an area of 7.5 minutes of longitude by 7.5 minutes of latitude. Topo maps of US areas are available from the US Geological Survey (USGS). These maps contain both elevation data, by means of countour lines, and location via coordinate systems. It will return a list of features that match the name you entered, along with the lat/long for each one. Enter your town in the "Feature Name" box and select the appropriate state before clicking on the "Send Query" button. *Lookup your Lat/Long online at the US Geological Survey GNIS Web site. There are several common methods for doing so: The first step, then, is finding your latitude and longitude as accurately and precisely as you can. The actual size of a grid square depends on the particular location, as the 1° of longitude represents different distances at different latitudes longitude lines are closer together at the Earth's poles than at the equator. The 4-digit grid squares cover a pretty big area, while the 6-digit grid square is fairly small. Finding a 6-digit grid square requires considerably more precision in latitude and longitude.
How you go about finding your latitude and longitude depends to some extent on whether you want to know your 4-digit grid square or your 6-digit grid square.
0 kommentar(er)
