Remote sensing is the study of something from a remote location or when one is not in physical contact with the object being studied. Satellite remote sensing gathers information from space and Earth orbit. When the information gathered is imagery of the Earth’s surface, that type of remote sensing is considered “Earth Observation.”
Remote sensing satellites, some as large as a truck or others as small as a shoebox, circle the Earth and use instruments to detect both visible light for photographs of the Earth’s surface as well as other parts of the electromagnetic spectrum used for ultraviolet, infrared (IR) and microwave imagery, mapping radio emissions on Earth, creating profiles of the atmosphere, and more. Once a remote sensing satellite records the imagery or sensing information, the data collected is sent to a ground station on the Earth and most often to another location, where the data is processed for interpretation and study.
Satellite remote sensing and imagery is used for a wide variety of commercial enterprise, government and consumer applications. Here are just a few examples: