The word “remote sensing” deals with the technology of getting information about earth’s surface. The science of observation and analysis of objects without any direct contact with the objects is remote sensing. Remote sensing has become very essential because of the inaccessibility to certain regions on earth. It works with the help of sensors that sense objects at distant places though sensors may not be in direct contact with the objects.
Some of the important devices used for remote sensing include satellites, camera, radar, sonar, seismograph etc. Most of the devices work by detecting the energy reflected from Earth. Remote sensing satellites are equipped with sensors looking down to the earth. Various image processing techniques are then used to decode the image obtained.
Images produced by the remote sensing satellites help us to learn more about our planet and the outer space. Remote sensing techniques help us create a map for a region. Lots of mapping and measuring could be done with the help of information that we get from remote sensing. Cartographers are people who make maps with the help of such information obtained. Maps created by using aerial photographs are called orthophoto maps.
The inaccessible objects either absorb or reflect radiation in different intensity and wavelength. Remote sensing is done with the study of absorbed or reflected radiation. With the help of absorbed or reflected radiation it is possible to find out the characteristics of different objects.