Remote sensing is the process of collecting data about the earth's surface and the environment from a distance, usually by sensors mounted on ground equipment, aircraft, or satellite platforms. Depending on the spectral location of the bands, sensors collect energy that is reflected (visible/infrared), emitted (thermal infrared), or backscattered (microwave) by a landscape surface and/or the atmosphere.

Remote sensing is one of the main data sources for GIS. Therefore, a brief overview of remote sensing is presented in this chapter: classifications of sensors according to platforms; number and location of spectral bands; and spatial, temporal, and radiometric resolutions. Examples of a sensor's adequacy as a function of mapping scale and type of GIS project are presented, along with a summary of the main steps followed to ...