Remote sensing involves the use of aerial photographs
, satellite image
s, and radar
to detect record and measure far away objects. This is currently done by sensing and recording reflected or emitted electromagnetic radiant energy
and transferring wavelengths
in the form of numeric data to a sensor
. The term was coined in the 1970's
though features on the earth's surface were remotely sensed much earlier than this time.
The following is a definition from the Manual of Remote Sensing
In the broadest sense, the measurement or acquisition of information of some property of an object or
phenomenon, by a recording device that is not in physical or intimate contact with the object or
phenomenon under study; e.g., the utilization at a distance (as from aircraft, spacecraft, or ship) of any
device and its attendant display for gathering information pertinent to the environment, such as
measurements of force fields, electromagnetic radiation, or acoustic energy. The technique employs
such devices as the camera, lasers, and radio frequency receivers, radar systems, sonar, seismographs, gravimeters, magnetometers, and scintillation counters.
- The practice of data collection in the wavelengths from ultraviolet to radio regions. This restricted
sense is the practical outgrowth from airborne photography. Sense (1) is preferred and thus includes regions
of the EM spectrum as well as techniques traditionally considered as belonging to conventional geophysics.
Source: Manual of Remote Sensing, 3rd Ed.
New York : Wiley, c1998.