Question

Explain the process of remote sensing.

Answer 1

Remote Sensing

1. The EMR (Electro-Magnetic Radiation) or solar radiation is the primary source of energy for remote sensing.
2. Sunlight travels from the sun through the atmosphere, before it reaches the earth’s surface. In the atmosphere, the sun’s rays are not obstructed by any object.
3. When solar radiation falls on the earth’s surface, some of its energy is absorbed. While some are transmitted through the surface, the rest is reflected. Surfaces naturally emit radiation in the form of heat.
4. Sensors in the satellite record the reflected and emitted radiation. Each surface/object possesses a characteristic spectral signature, a unique pattern of reflecting sunlight.
5. The energy recorded by the sensor has to be transmitted to a ground station where the data are processed into an image.
6. The processed image is interpreted either visually by human interpreters or by computer-aided techniques called digital image processing to identify and distinguish between the different spectral signatures to get information about objects/places.
7. Finally, we understand and apply the extracted information in mapping the area or assisting in solving a particular problem.