Remote sensing is the method of observing the earth and collecting information about objects and areas on the surface of the earth without having direct contact with the objects or areas under study. Remote sensing devices operate by measuring the intensity of electromagnetic radiations reflected or transmitted by various objects on the earth. Specially designed cameras capture the images of the earth after remotely sensing them. Through applying the technique of remote sensing the atmosphere and surface of the earth can be observed from the air or from beyond the space through satellites. For instance, cameras from aircraft and satellites capture very large areas on the surface of the earth that one cannot ordinarily see by standing anywhere on the ground. Basically a multidisciplinary science, remote sensing combines various disciplines like satellite launching, telecommunication, electronics, photography, spectroscopy, optics and computer science to act as an integrated remote sensing system (Campbell, 1996). Remote sensing finds application in land use and soil mapping, agriculture, forestry, archeological investigations, city planning, weather prediction, studying effects of oil spills, assessing damages from natural disasters etc.,
Remote sensing along with Geographical Information System (GIS) is an effective tool in the management of natural disasters. For instance, the objective of disaster management during a hurricane is effective monitoring of the situation, suggesting suitable contingency plans, simulation of a complicated hurricane as precisely as possible for the purpose of coming up with suitable prediction models and preparation of appropriate spatial database. At the stage of preventing the disaster, GIS finds application in managing huge data required for the assessment of vulnerability and ensuing hazards. While getting ready for the preparedness of the hurricane disaster GIS and remote sensing act as tools for planning the routes for evacuation and designing emergency operations and centers. Integration of the data collected by satellites through remote sensing along with the design database helps in designing appropriate disaster warning systems. Most importantly, during the relief phase, GIS along with Global Positioning System (GPS) is tremendously useful in rescue and search operations in severely affected areas (Sharma & Joshi, 2015). At the rehabilitation stage, remote sensing data and GIS are combined together and used to assess the information on damage for planning reconstruction. Similarly, data that are remotely sensed can be effectively used in integration with GIS and GPS for quick assessment of the severity of damage during earthquakes, forest fires, flooding and cyclones.
Remote sensing technique can be used to explore the ocean floor through sonar systems equipped in navigating ships to generate images of the ocean floor without plunging oneself deep into the sea. Ocean bottom mapping finds application in understanding the various physical features of the ocean including mountain ranges and canyons and the marine eco system. Remote sensing systems can also accurately measure the temperature of the sea through microwave radiometers. The sea surface temperature is a key parameter that decides the weather, and hence measuring and mapping the sea surface temperature helps in predicting the weather, particularly the ocean and fisheries forecasts. This has been found to be very useful in predicting cyclones with incredible accuracy.
Remote sensing has made convenient managing vast tracts on the earth easy for man. For instance, by mapping forest fires from the space, rangers can survey wide areas they cannot see from the land and plan timely protective measures. On the other hand, it helps town planners and researchers to track the growth of a city at the expense of natural resources like farm lands or forests. In short, remote sensing techniques help us to survey the health of the earth from time to time and plan appropriate measures to sustainably use the resources it provides us apart from thankfully saving it from man-induced disasters.
References
Campbell, J. (1996). Introduction to remote sensing (2nd ed.). New York: Guilford Press.
Sharma, Ashok Kumar & Joshi, Varun (2015). Use of remote sensing and GIS in disaster management in Gangtok area, Sikkim. Geospatial World. Retrieved from http:// geospatialworld.net/Paper/Technology/ArticleView.aspx?aid=985
