Aquatic Pollution and Coastal Management

Unit 14 : Coastal zone management and information system

14.6.Remote Sensing (RS) & Geographic Information System (GIS)
Remote Sensing is the science or technology to collect thematic and geometic information of an objective without having any physical contact with the object. In the present context, the term Remote Sensing is restricted to indentify various objects/features on the earth’s surface using Visible (0.4 TO 0.7 µm), Thermal Infrared (8 to 14 µm) and microwave (0.1 to 30 cm) regions of solar radiation (EMR) coming through atmospheric windows and are reflected, emitted or scattered by the objects depending on its physical and chemical properties.
The remote sensing techniques are classified into two types depending on the source of energy which illuminate the object under study.
Passive RS – In passive remote sensing the naturally radiated or reflected energy from the earth’s surface features is measured by the sensors operating in different spectral bands of the air-borne/space platform on board.
Active RS – An active remote sensing system supplies its own source of energy to illuminate the objects and measures the reflected energy to the system.

RS Tools now available

• The aero-space data, presently, available with us are:
• Aerial Photographs
• Radar Photographs/Images
• Earth Observing Satellite (EOS) Imagery
• Meteo-satellite data