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RS happens due to the radiation of Electromagnetic waves from coming the sun
C (Velocity of light)
Source of Electromagnetic waves
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Source: https://phys.org/news/2018-04-vr-focus-nanostructure-meta-lenses.html
Visible Band of Electromagnetic waves
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Characteristics of Electromagnetic radiation
Electromagnetic Energy can be modelled in two ways
i. By waves ii. By Photons (Energy bearing particles)
Electromagnetic waves consist of a combination of oscillating electrical
and magnetic fields, perpendicular to each other.
C (Velocity of light)
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i. It can travel through empty space.
ii. The speed of light is constant in space.
iii. Wavelength: Distance between crests or troughs through visible light
iv. Velocity: 186,000 miles per second or 300,000 kilometers per second or
299,790,000m/s or 3*108 m/s
v. Amplitude: The amplitude of electromagnetic waves relates to its intensity
or brightness(as in the case of visible light) or the maximum extent of a
vibration or oscillation, measured from the position of equilibrium (mid
point of wavelength)
vi. Frequency:
The number of crests of the waves that pass by a point per second.
Measured in units of hertz(Hz)
1 hertz = 1 wave crest/second
Characteristics of Electromagnetic radiation
/ Crest
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/ Crest
Velocity of light, c
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Note the trends: bluer light has shorter wavelength, higher frequency, and more
energy. Redder light has longer wavelength, lower frequency, and less energy.
Wavelength is a reciprocal of Frequency
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f or V = c/
Relation between the speed of light (c),
wavelength ( ), and frequency (f or V ):
Thus, there is an inverse relationship between wavelength and frequency
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Thus (frequency [f or V] * wavelength[lambda]) is equal to a constant (c)
Relation between the speed of light (c), wavelength ( ),
and frequency ( ƒ or v):
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Measurement of Electromagnetic Energy(E/Q)
The amount of energy held by a photon of a specific
wavelength is given by
E or Q = h v
Since c = v
v/ƒ = frequency
v/ƒ = c/
h = 6.6262 x 10 -34 j/s Plank’s constant
E or Q = h x c/
c = 3 x 10 8 m/s Speed of light is constant
E or Q =
6.6262 x 10 -34 (3 x10 8)
x
(500nm x 10 – 9 m)
E or Q = (3.98 x 10 -19 j)
(500 x 10 – 9 m)
= 500nm
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Types of Energy Resources/Types of RS on the basis of Energy
(1.Passive & 2.Active)
Source: https://www.google.com/
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1. Passive Remote Sensing: Makes use of sensors that detect the
reflected or emitted electro-magnetic radiation from natural sources.
Source: https://www.google.com/
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2. Active remote Sensing: Makes use of sensors that detect reflected
responses from objects that are irradiated from artificially-generated
energy sources, such as radar.
Source: https://www.google.com/
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