BASICS OF REMOTE SENSING
The human body perceives the surrounding world through five senses that is Touch, Taste, Smell, Hear, and See. The first two senses (Touch, Taste) require contact of our sense organs with the objects. However, we acquire much information about our surrounding through senses of sight and hear which do not require close contact of sense organs with the external objects. In other words, the human body perform remote sensing to acquire information about the surrounding world.
The term Remote Sensing refers to the activities of recording, observing, perceiving information of objects or events at far away ( Remote) places. In Remote Sensing application, the sensors are not in direct contact with the objects or events being observed. The electromagnetic radiation is normally used as an information carrier in remote sensing.
What is REMOTE SENSING ?
The internationally accepted definition of remote sensing is “the science and art of obtaining information about an object, area or phenomena through analysis of data acquired by a device that is not in contact with the object, area or phenomena under investigation.”
The following seven elements are essential for remote sensing interpretation ----
1. ENERGY SOURCE or ILLUMINATION
The first and the essential requirement for remote sensing is to have an energy source, which illuminates or provides electromagnetic energy to the target. The sun is considered as the prime source of energy.
2. RADIATION & THE ATMOSPHERE
The solar energy while traveling from source to target and further from target to the sensor comes in contact with the atmosphere. This interaction between energy and atmosphere is useful in the interpretation of objects on the earth.
3. TARGET
Once the energy make its way to the target though the atmosphere, it interacts with the target depending on the properties of both the target and the radiation.
4. SENSOR
The Electromagnetic Radiation when scattered by or emitted from the target is collected and recorded by the sensor, which is not in contact with the target. A sensor highly sensitive to all wavelengths, yielding spatially detailed data on the absolute brightness( Radiance) from a scene as a function of wavelength throughout the spectrum.
5. TRANSMISSION ,RECEPTION AND PROCESSING
The Electromagnetic Radiation recorded by the sensor is transmitted (in electronic form) to a receiving and processing station, where the satellite data are processed into an image (Hardcopy and/or Softcopy). As soon as the radiance Vs wavelength responses over a terrain element is generated ,it would be processed into an interpretable format and then recognized as unique to the particular terrain elements from which it is received .
6. INTERPRETATION & ANALYSIS
The processed image is interpreted and analyzed by skilled scientists visually and digitally in order to extract information about the target, which was illuminated. The multiple data users are people ,who have knowledge in greater depth ,both in their respective disciplines and in remote sensing data acquisition, analysis techniques.
7. APPLICATION
The interpreted and analyzed data is combined with ground check in solving a particular problem.
These seven elements comprise the remote sensing process from beginning to end.
The human body perceives the surrounding world through five senses that is Touch, Taste, Smell, Hear, and See. The first two senses (Touch, Taste) require contact of our sense organs with the objects. However, we acquire much information about our surrounding through senses of sight and hear which do not require close contact of sense organs with the external objects. In other words, the human body perform remote sensing to acquire information about the surrounding world.
The term Remote Sensing refers to the activities of recording, observing, perceiving information of objects or events at far away ( Remote) places. In Remote Sensing application, the sensors are not in direct contact with the objects or events being observed. The electromagnetic radiation is normally used as an information carrier in remote sensing.
What is REMOTE SENSING ?
The internationally accepted definition of remote sensing is “the science and art of obtaining information about an object, area or phenomena through analysis of data acquired by a device that is not in contact with the object, area or phenomena under investigation.”
The following seven elements are essential for remote sensing interpretation ----
1. ENERGY SOURCE or ILLUMINATION
The first and the essential requirement for remote sensing is to have an energy source, which illuminates or provides electromagnetic energy to the target. The sun is considered as the prime source of energy.
2. RADIATION & THE ATMOSPHERE
The solar energy while traveling from source to target and further from target to the sensor comes in contact with the atmosphere. This interaction between energy and atmosphere is useful in the interpretation of objects on the earth.
3. TARGET
Once the energy make its way to the target though the atmosphere, it interacts with the target depending on the properties of both the target and the radiation.
4. SENSOR
The Electromagnetic Radiation when scattered by or emitted from the target is collected and recorded by the sensor, which is not in contact with the target. A sensor highly sensitive to all wavelengths, yielding spatially detailed data on the absolute brightness( Radiance) from a scene as a function of wavelength throughout the spectrum.
5. TRANSMISSION ,RECEPTION AND PROCESSING
The Electromagnetic Radiation recorded by the sensor is transmitted (in electronic form) to a receiving and processing station, where the satellite data are processed into an image (Hardcopy and/or Softcopy). As soon as the radiance Vs wavelength responses over a terrain element is generated ,it would be processed into an interpretable format and then recognized as unique to the particular terrain elements from which it is received .
6. INTERPRETATION & ANALYSIS
The processed image is interpreted and analyzed by skilled scientists visually and digitally in order to extract information about the target, which was illuminated. The multiple data users are people ,who have knowledge in greater depth ,both in their respective disciplines and in remote sensing data acquisition, analysis techniques.
7. APPLICATION
The interpreted and analyzed data is combined with ground check in solving a particular problem.
These seven elements comprise the remote sensing process from beginning to end.
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