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Sky wave propagation is possible because of ionosphere. Ionosphere is the region consisting of ions produced in the higher level of atmosphere almost at a height of 90km. The scientific fact is that the refractive index is inversely related to the ionic density. Because of various concentration of ions in the ionosphere, the refractive index is different. As radio waves make an entry through this region, the ray has to pass from the region of higher refractive index to lower, so the radio waves get deviated from the normal. So stage by stage, the radio waves get turned back towards the earth. This seems as if it has been reflected by the ionospheric layer. So short waves, also known as sky waves, with a range of frequency 3 to 30 MHz are better sent back to the earth. That is why irrespective of the curvature of the earth, the signals transmitted at London will be received by a radio in a town in TamilNadu, India.
Wiki User
∙ 14y ago
Wiki User
∙ 15y agoBecause radio waves of a certain frequency don't penetrate the ionosphere, they bounce. It's like getting a ball to go around corners by bouncing it off something to change its direction.
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How does the ionosphere affect AM radio transmissions?
these ionised particles,reflect the radio wave to earth back.depending on the density of the ionosphere,at the time determins the amound of radio waves.this will affect clear reception.the height of the ionosphere involves reflecting angle,which gives long length hops.in this way long distance communications are affect by ionosphere.
Which Atmospheric layer reflects radio wave?
It is the ionosphere, a general region that includes all of the thermosphere and parts of the two bordering layers. In this region, between 60 and 1000 kilometers above the Earth, ionized particles refract and reflect radio waves back toward the ground. This enables radio transmissions that are normally "line of sight" only to reach over the horizon for hundreds or thousands of miles. This includes broadcast radio (HF) and shortwave bands.
Does some wavelength of radio wave are reflected by the ionosphere and come back to Earth?
Question: Why do low freqs reflect from the ionosphere while high freqs go straight thru?ANS:- ANSWER: -for the same reason that high freqs can pass thru a parabolic dishof screen but the low freq reflects off the screen.The spacing of the screen wires have to be a small % of wavelength.The ionosphere must have ions that are spaced further apart than say 1 meter---so that a 300MHz signal (wavelength = 1 meter) will not see it as a "solid"whereas a 1MHz AM-band signal (wavelength =300 meters) will see the ion fieldas as as a "solid" wall to bounce off. (PhilDragonetti, RF Engineer)
How do you communicate with astronauts if radio waves are reflected back to earth?
Radio signals at frequencies up to roughly 40 to 60 MHz are absorbed or reflected from the ionosphere. At higher frequencies, the signals easily penetrate the ionosphere and continue on into space. This is the reason that AM radio (1 MHz) and "short-wave" broadcasts (4-13 MHz) are often received from great distances, but TV (54 MHz and up) and FM radio (100 MHz) are not.
What layer of the atmosphere do radio waves heading upward from earth often bounce off?
The Ionosphere reflects longer radio waves back to Earth. It varies in height going up at night giving the waves a long distance bounce.Flat vertical walls. Better refraction will Non-ferous metals. Horizontal plan will distort the image of the wave.\ CIV
What is the function of the ionosphere?
Electrically charged gas particle, Ionizeed, to help the transmition of radio wave. This is especially important for AM Radio Station
What is the effects of ionosphere on transmission?
Ionosphere consists of ionised species which reflect the radio waves that are directed towards it.Thus it redirects the radiowaves towards the target.This avoids the radio waves getting obstructed by ground wave propogation.
What characteristics of the ionosphere enable radio waves?
The ionosphere has nothing to do with radioactivity, and there is nothing in nature that is called a "radio active wave."Because the ionosphere contains electrical charges, it is able to reflect radio waves.
What characteristic of the ionosphere enables radio active waves?
The ionosphere has nothing to do with radioactivity, and there is nothing in nature that is called a "radio active wave."Because the ionosphere contains electrical charges, it is able to reflect radio waves.
Which type of electromagnetic wave would reflect from the ionosphere?
shortwave radio band
How does the ionosphere affect AM radio transmissions?
these ionised particles,reflect the radio wave to earth back.depending on the density of the ionosphere,at the time determins the amound of radio waves.this will affect clear reception.the height of the ionosphere involves reflecting angle,which gives long length hops.in this way long distance communications are affect by ionosphere.
Which Atmospheric layer reflects radio wave?
It is the ionosphere, a general region that includes all of the thermosphere and parts of the two bordering layers. In this region, between 60 and 1000 kilometers above the Earth, ionized particles refract and reflect radio waves back toward the ground. This enables radio transmissions that are normally "line of sight" only to reach over the horizon for hundreds or thousands of miles. This includes broadcast radio (HF) and shortwave bands.
Type of radiation stopped in the ionosphere?
Some, not all, radio waves. The reflected ones are the ones used for short-wave radio.
What wave is used in sattellite radio transmission?
electromagnetic wave
What has the author K G Budden written?
K. G. Budden has written: 'The wave-guide mode theory of wave propagation' -- subject(s): Radio waves, Wave guides 'Radio waves in the ionosphere' -- subject(s): Ionospheric radio wave propagation
What has the author T W Bennington written?
T. W. Bennington has written: 'Short wave radio and the ionosphere'
Sky wave antenna?
The term skywave is used to refer to the reflect radio waves from the ionosphere. ?æSkywave is used most frequently in shortwave radio broadcasts.
