In general terms, remote sensing is the science and practice of acquiring information about an object without actually coming into contact with it. In terms more appropriate for our purposes remote sensing is a technology for sampling reflected and emitted electromagnetic (EM) radiation from the Earth's terrestrial and aquatic ecosystems and atmosphere. This is typically done by recording images from airplanes and satellites to help identify or better understand features on the Earth's surface. In this article we will discuss a wide set of techniques, often known by the alternative name of 'Earth observation' (EO). We will only address EM remote sensing, so geomagnetic and acoustic remote-sensing techniques (sonar and seismic sounding) will not be covered.
A simple example of a remote-sensing instrument is a photographic or digital camera. A camera records energy in the form of light that is reflected from a surface to form an image. Most photographic cameras record visible light so that when we look at the photograph the image resembles the feature that was photographed. More sophisticated remote-sensing instruments are able to record energy outside of the range of visible light. Data from remote-sensing instruments can be recorded as images or, in the case of lidar, a series of point data.
Was this article helpful?