Exploration of resources
Exploration of resources involves complex techniques which depend on the physical, chemical and biological properties of a particular resource. Now-a-days, in our country, much of the exploration is done by analysis of photographs taken from air raft or spacecraft 9 (satellites) and other data supplied by the sensors mounted on these vehicle by a method called' remote sensing'. You may like to know something about the methods used for exploration of resources.
Conventional Methods: In olden days, discovery of minerals or of petroleum wis purely accidental. People used to know about the hidden treasures of the Earth, when they used to dig out land for water or for construction of houses. Sometimes, while tilling land, fanners struck luck and discovered precious metals and minerals. However, in this way, they could only hit upon the mineral wealth which lay close to the surface. Now, many techniques are used for systematic exploration of the hidden resources, and drilling or digging is undertaken when preliminary surveys have clearly indicated what is underneath and how much is likely to be found.
Remote Sensing Method: Principle Remote sensing is a method of collecting information about ground objects like soil, water, vegetation and minerals, from a remote place, such as an aircraft or a satellite. This technique not only enables us to locate various resources, but also helps us to know about their quantity and quality. The simplest device could be a camera canied by an aeroplane to photograph large areas of land systematically. Television cameras could be mounted on satellites and they could take pictures showing details of clouds, water, forests or buildings on the earth. Both these are "optical" methods of remote sensing because visible light is used by the cameras. But one could send out radio waves from the satellites and observe how they are reflected or absorbed on the surface of the earth. Usually radio waves of wavelengths as small as a few centimetres called 'microwaves', are used for such studies, because these waves penetrate through klouds and their reflections also go through the clouds to reach the satellite. Similarly, infra-red signals can be sent from the satellite and reflections studied to reveal the nature of the reflecting surface. Remote sensing of water resburces , Radio waves of the shortest known wavelengths are called 'gamma rays'. These are given off by atoms of several elements. As a result, the ground soil sends out gamma rays which