Geographers study Earth’s places, people, environments, and systems. They use different tools to collect information, find patterns, create maps, and understand how places change over time. Some geographic tools have been used for hundreds of years. Others depend on satellites, computers, and other modern technologies.
Maps
A map is a visual representation of an area. Maps help people understand where places and features are located. Different kinds of maps are designed for different purposes.
A political map may show countries, states, cities, and borders. A physical map may show mountains, rivers, deserts, and other natural features. A road map helps people plan routes between locations. Thematic maps display information about a particular topic, such as climate, population, languages, natural resources, or land use.
Geographers study and create maps to identify patterns. For example, a geographer might compare a rainfall map with a farming map to investigate how precipitation affects the crops grown in different places.
Surveying Equipment
Surveying is the process of measuring locations, distances, angles, and elevations on Earth’s surface. Surveyors, geographers, engineers, and construction professionals may use surveying equipment to gather precise measurements.
One traditional surveying tool is a theodolite. A theodolite is an instrument mounted on a tripod that measures horizontal and vertical angles. Surveyors can combine these measurements with information about distance and elevation to determine the positions of features on the ground.
Modern surveying often uses electronic instruments and satellite-based technology. Accurate survey measurements help people create maps, mark property boundaries, plan roads, and design buildings.
Global Positioning System
The Global Positioning System, or GPS, uses signals from satellites to help a receiver determine its location on Earth. GPS receivers are found in smartphones, vehicles, ships, airplanes, and specialized surveying equipment.
A GPS receiver calculates its position by comparing signals from several satellites. It can provide information such as latitude, longitude, elevation, direction, and speed.
People use GPS for many purposes. Travelers use it to navigate, emergency workers use it to locate people, and scientists use it to record the positions of features they are studying. Geographers can also use GPS to collect location data that will later be added to a map.
Geographic Information Systems
A Geographic Information System, or GIS, is a computer-based system used to store, organize, analyze, and display geographic information. GIS allows users to place different kinds of information in layers on a digital map.
For example, one layer might show roads, another might show rivers, and another might show population. Examining these layers together can reveal relationships that might otherwise be difficult to notice.
Communities can use GIS to decide where to build schools, parks, or public transportation routes. Emergency planners can use it to identify areas at risk from floods or wildfires. Geographers can use GIS to study changes in population, land use, climate, and the environment.
Remote Sensing
Remote sensing means collecting information about an area without directly touching or visiting it. Sensors on satellites, airplanes, and drones can gather data about Earth from a distance.
Some remote-sensing instruments take photographs using visible light. Others detect types of energy that human eyes cannot see, such as infrared energy. These instruments can provide information about temperature, plant health, water, clouds, and changes to Earth’s surface.
Geographers compare remote-sensing images taken at different times to study change. They might track the growth of a city, observe damage after a hurricane, measure the shrinking of a glacier, or study changes in forests and farmland.
Using Tools Together
Geographic tools are often most useful when they are combined. A geographer might use GPS to record the location of a stream, remote sensing to observe the surrounding land, and GIS to organize the information in layers. The geographer could then create a map that explains how the stream and nearby land affect one another.
These tools help geographers answer questions about where things are located, why patterns exist, how places have changed, and how people can make informed decisions about the future.