

Remote sensing is the art and science of making measurements of the earth using sensors on airplanes or satellites. These sensors collect data in the form of images and provide specialized capabilities for manipulating, analyzing, and visualizing those images. Remote sensed imagery is integrated within a GIS. For more, see the Principles in Remote Sensing tutorials from the Satellite Observations in Science Education site.
Remote sensing increases the capabilities of GIS by providing geospatial information even in hazardous areas, such as those experiencing natural calamities. It also provides users with a way to systematically collect data for various applications. Moreover, its unobtrusive processes allow researchers to map areas and objects without disturbance.
GIS and remote sensing both have a number of applications in various fields, forming the foundation of data-driven approaches in engineering, conservation, research, and resource management.