Remote sensing is the measurement of information of an object or phenomenon, by a device that is not in physical contact with the object. Thus an aircraft taking photographs, Earth observation and Weather satellites, even monitoring a fetus in the womb through ultrasound, most remote sensing systems expect to convert a photograph or other data item to a distance on the ground.

Generally speaking, remote sensing works on the principle of the inverse problem. In order to generate maps, most remote sensing systems expect to convert a photograph or other data item to a distance on the ground. Interpretation is the critical process of making sense of the data. In modern systems that produce digital data, often the tool is a family of computer programs that interpret the data to form maps, or statistical analyses