GeoReferencing & Geocoding
Georeferencing Raster Images
A raster image, also known as a bitmap, is a way to represent digital images via pixels. The raster image can include a variety of formats including .tif .gif, .jpg, and .bmp. A crucial element of any mapping project is registering and integrating maps with correct real world coordinates; Latitude and Longitude (Lat/Long). This procedure is called georeferencing. If the maps are not georeferenced, no “intelligent” information can be displayed or positioned on the map. Depending on the source materials and the specifications of the project, maps can be registered to either a coordinate system, or to another base map such as a digital orthophoto.
Georeferencing Vector Data
Vector data can be georeferenced (or rubbersheeted) to real world coordinates; Latitude and Longitude (Lat/Long). Rubbersheeting is a nonuniform adjustment of a data set based on the association of known control points to new locations. Vector data can be either rubbersheeted to match existing base maps or the data may be projected into a specific coordinate system. Unlike raster images, vector images contain useful “intelligent” data/information that can be used in various Geographic Information Systems (GIS) software programs.
Geocoding is the process of transforming a description of a location—such as a pair of coordinates, an address, or a name of a place—to a location on the earth's surface. You can geocode by entering one location description at a time or by providing many of them at once in a table. The resulting locations are output as geographic features with attributes, which can be used for mapping or spatial analysis.
You can quickly find various kinds of locations through geocoding. The types of locations that you can search for include points of interest or names from a gazetteer, like mountains, bridges, and stores; coordinates based on latitude and longitude or other reference systems, such as the Military Grid Reference System (MGRS) or the U.S. National Grid system; and addresses, which can come in a variety of styles and formats, including street intersections, house numbers with street names, and postal codes.
What can geocoding be used for?
From simple data analysis to business and customer management to distribution techniques, there is a wide range of applications for which geocoding can be used. With geocoded addresses, you can spatially display the address locations and recognize patterns within the information. This can be done by simply looking at the information or using some of the analysis tools available. You can also display your address information based on certain parameters, allowing you to further analyze the information.