Geographers use a number of specialized tools to examine, explore, and interact with spatial data. One of the oldest tools is the map—a paper representation of space showing where things are. While maps will never go out of style, computers have enhanced our ability to store, retrieve, and analyze spatial data through the development of geographic information systems (GIS). Acquiring geographic information for input to GIS has recently been made much easier through use of the global positioning system (GPS), which allows hand-held electronic equipment, linked to signals from orbiting spacecraft, to easily determine the exact latitude, longitude, and elevation of any point on the Earth’s surface to within a few meters.
Satellites bearing imaging instruments have provided a wealth of information about the Earth’s surface layers, including land, oceans, and atmosphere, that is vital to geographic study. The field of processing, enhancing, and analyzing images and measurements made from aircraft and spacecraft is known as remote sensing. Recent developments linking remote sensing, GIS, and GPS with the Internet have produced new Earth visualization tools, such as Google Earth, that are also of great interest to geographers.
Tools in geography also include mathematical modeling and statistics. Using math and computers to model geographic processes is a powerful approach to understanding both natural and human phenomena. Statistics provides methods that can be used to manipulate geographic data so that we can ask and answer questions about differences, trends, and patterns. Because these tools rely heavily on specialized knowledge, they are not included here. Our text does, however, present many examples of geographic information obtained using modeling and statistics.