Maps are not just paper documents in textbooks. They have become essential for delivery of contemporary online services through smartphones, tablets, and computers. Location data used in applications and devices are collected through electronic tools. While these digital systems allow geographers to explore more of Earth, they still rely on field work to collect data and ground-truth conclusions. They interview people, conduct surveys, take photographs, and have informal observations of the landscape around them.

GIScience: Analyzing Data

Geographic information science (GIScience) is the analysis of data about Earth acquired through satellite and other electronic information technologies. A geographic information system (GIS) captures, stores, queries, and displays the geographic data. GIS produces maps (including those in this book) that are more accurate and attractive than those drawn by hand. Each type of information is stored in a layer.

Some of the data used in GIS come from photos. The science of taking measurements of Earth’s surface from photographs is called photogrammetry. The acquisition of data about Earth’s surface from a satellite orbiting Earth or from other long-distance methods is remote sensing. At any moment, an aerial sensor attached to a satellite, airplane, or drone may be recording the image of a tiny area on Earth’s surface

GIScience helps geographers create more accurate and complex maps and measure changes over time in the characteristics of places. Layers of information acquired through remote sensing and produced through GIS can be described and analyzed. GIScience enables geographers to calculate whether relationships between objects on a map are significant or merely coincidental.

GPS: Pinpointing Locations

Our smartphones, tablets, and computers are equipped with Global Positioning System (GPS), which is a system that determines the precise position of something on Earth. The GPS in use in the United States includes two dozen satellites placed in predetermined orbits; a series of tracking stations to monitor and control the satellites; and receivers that compute position, velocity, and time from the satellite signals.

GPS is most commonly used for navigation. Pilots of aircraft and ships stay on course with GPS. On land, GPS detects a vehicle’s current position, the motorist programs the desired destination into a GPS device, and the device provides instructions on how to reach the destination.

Thanks to GPS, our electronic devices provide us with a wealth of information about the specific place on Earth we currently occupy. The locations of all the information we gather and photos we take with our electronic devices are recorded through geotagging, which is identification and storage of a piece of information by its precise latitude and longitude coordinates. Geotagging has led to concerns about privacy (refer ahead to the Debate It! feature).

VGI: Making Maps Yourself

Most of the maps fed into our electronic devices are provided by a handful of companies (Figure 1-13). However, smartphones, tablets, and computers enable individuals to make maps and share them with others. Volunteered geographic information (VGI) is the creation and dissemination of geographic data contributed voluntarily and for free by individuals. VGI is part of the broader trend of citizen science, which is scientific research by amateur scientists, and participatory GIS (PGIS), which is community-based mapping. Citizen science and PGIS collect and disseminate local knowledge and information through electronic devices.