Lines of latitude and longitude can be used to pinpoint any place on Earth.
Geocoding is the process of converting informal locations, such as street addresses, into formal geographic coordinates. Locations are given a unique set of coordinates to mark their exact place on earth. The GPS technology that many have come to depend on is made possible by geocoding and the creation of geographic information databases.
History
Geocoding came into being as a way for the United States Census Bureau to make the collection of census data easier, beginning with the 1970 census. Since then, improvements in computers and satellite technology have increased the accuracy of geocoding. Geocoding is vital to government bureaus that require socioeconomic data for decision making. Global positioning systems also depend on accurate geocoding to function properly. Today, the government agency primarily responsible for geocoding in the United States is the U.S. Geological Survey.
Latitude and Longitude
Geocoding uses longitude and latitude, a grid system that can mark any point on Earth. Longitude lines run from north to south, and measure distance east or west of the international dateline. Latitude lines run from east to west, and measure distance north or south of the equator. Latitudinal and longitudinal locations are typically measured in degrees and minutes, and can also be expressed as decimals with whatever level of specificity is needed. Thus, 24.73 degrees North is more specific than 24.7 degrees North, and 24.732645 degrees North is far more specific than either. By getting more specific, geographical coordinates can describe a place of any scale or size; this allows addresses to be linked to unique geographical coordinates, and makes geocoding possible.
Collecting Data
The process of geocoding takes place in two stages. The first stage is data collection. Geographical data is collected from several different types of sources, including aerial photographs, satellite images and digital maps. Today, data is also collected manually by people carrying hand-held GPS devices. By actually going out into the field, these people are able to visually confirm the longitudinal and latitudinal coordinates of specific places.
Geographic Information Systems
Once geographic information has been collected, it needs to be compared, contrasted and assessed. This is the second step of geocoding. Geographers use complex programs called geographic information systems to help them analyze raw data and assign correct coordinates to different places. Once researchers are reasonably sure that a set of coordinates is accurate, the information goes into a geographic information database. The information is then shared with government agencies, municipal organizations and educational institutions that use geographic information for scientific study.
Application
Advances in geocoding have had positive impacts for many professions. Emergency dispatchers have access to geographic information made possible by geocoding initiatives, and emergency personnel such as police, firefighters and ambulances can now depend on mobile GPS devices to more accurately and easily respond to crises. Many taxi drivers also have begun to use GPS technology to more easily move between addresses. Wildlife biologists use GPS technology to track the movements of different animals, birds and fish. People use GPS technology every day to quickly obtain real-time directions while operating a motor vehicle. The technology is also used for "geocaching," an recreational activity in which players use geographic coordinates to locate small hidden objects in both rural and urban settings.
Tags: geographic information, degrees North, more specific, degrees North more, east west, geographic coordinates
