Understanding the concepts of Remote Sensing
What is Remote Sensing by definition?
As per the definition “Remote Sensing is the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation.”
What is it in simple words?
Let’s consider you are reading this text on your mobile phone or computer. The light from the screen is incident on your eyes and you are able to distinguish between the white and black parts of the screen. You are able to recognize the black parts as alphabets that form words. And a collection of words that form meaningful sentences. In the case of reading a paper, light from the surrounding is incident on the paper and reflected back to your eyes.
Components of Satellite/Aerial Remote Sensing and Data Acquisition.
- Source of Energy — The most important source of energy in our solar system is the Sun. Sun propagates energy in the form of light and illuminates our earth. Propagation of energy takes place through our atmosphere and incidents on the surface.
- Energy interactions with the surface features — As the energy by the sun incidents on the earth it interacts with its features. Various objects absorb, refract and reflect the energy as per their property and wavelength of the electromagnetic radiation.
- Reflection back to the sensor — The energy reflected from the earth is collected by the sensors of satellites or airplanes.
- Transmission of information — The energy recorded by the sensor is transmitted back to the processing station on the earth in digital form.
- Collected data — The collected data which is available in the form of satellite images and raster data is used for various analyses, studies, and making maps.
It is the order of radiation according to wavelength and frequency. The longer the wavelength, the lower the frequency, and the shorter wavelength the higher frequency. Various wavelengths are used by different sensors and for various purposes.