Any satellite communications system network operator using a Ku-Band system (12/14 GHz or higher frequencies) will face the effects of rain fade at some time. But to understand why this weakening occurs with Ku-Band transmissions, you must first understand the causes of satellite rain fade. Two of the most common causes are listed below.
Scattering can be caused by either refraction or diffraction:
It refers primarily to the absorption of a microwave Radio Frequency (RF) signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a storm front. Rain attenuation or fade can be caused by precipitation at the uplink or downlink location. However, it does not need to be raining at a location for it to be affected by rain fade, as the signal may pass through precipitation many miles away, especially if the satellite dish has a low look angle.
From 5 to 20 percent of rain fade or satellite signal attenuation may also be caused by rain, snow or ice on the uplink or downlink antenna reflector, radome or feed horn.
Due to multiple reflections
satellite is satellite
attenuation due to atmospheric conditions.
definition of optical satellite communication
The first communication satellite was Echo NASA
The problems are attenuation of signals due to certain atmospheric condition . Depending on the elevation, the signal has to penetrate a small ar larger percentage of the atmosphere. generally an elevation less than 10 degrees is considered useless for communication.
The satellite is in space, the satellite receiver is on Earth. The rain is in the atmosphere between the satellite and the receiver. The more rain, the more of the signal from the satellite will be used up by the atmosphere on its way down instead of reaching the receiver.
Attenuation is a measure of how much loss a signal experiences when it travels down a communication medium( loss as heat, absorbed by communication medium).It is mesured in decibels Attenuation is a term that refers to any reduction in the strength of a signal, when transmitting over a long dinstance. Attenuation occurs with any type of signal, whether digital or analog. It is also called loss of signals, The extent of attenuation is usually expressed in units called decibels (dBs).
Why Fresnel zone affecting satellite and ground communication?
Com = Communication, Sat = Satellite
Any satellite communications system network operator using a Ku-Band system (12/14 GHz or higher frequencies) will face the effects of rain fade at some time. But to understand why this weakening occurs with Ku-Band transmissions, you must first understand the causes of satellite rain fade. Two of the most common causes are listed below.Absorption - Part or all of the energy generated when a radio wave strikes a rain droplet. The droplet is converted to heat energy and absorbed by the droplet.Scattering - A non-uniform transmission medium (the raindrops in the atmosphere) causes energy to be dispersed from its initial travel direction.Scattering can be caused by either refraction or diffraction:Refraction - The refractive index of the water droplets encountered by the radio wave.Diffraction - the travel direction of the radio wave also changes as it propagates around the obstacle in its path (a water droplet).It refers primarily to the absorption of a microwave Radio Frequency (RF) signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a storm front. Rain attenuation or fade can be caused by precipitation at the uplink or downlink location. However, it does not need to be raining at a location for it to be affected by rain fade, as the signal may pass through precipitation many miles away, especially if the satellite dish has a low look angle.From 5 to 20 percent of rain fade or satellite signal attenuation may also be caused by rain, snow or ice on the uplink or downlink antenna reflector, radome or feed horn.
The Impact of Satellite Rain FadeRain rate is the most common factor used to determine rain fade. Rain fade seems to correlate very closely with the volume of raindrops (expressed in cubic wavelengths) along the path of propagation. This is opposed to the common misconception that the degree of attenuation is proportional to the quantity or individual size of the raindrops falling near the receive site.Pinpointing the specific factor that lead to attenuation is essential to accurately predicting the problem. Models can be developed from this data to chart the effects of rain fade on a regional or individual site basis. From this information, you can determine the correct antenna size you'll need to counteract the effects of satellite rain fade.This doesn't mean, however, that buying the largest antenna possible will solve all rain-related problems. There is a point (usually under extremely heavy rain conditions and only for very brief periods) where virtually 100% of the satellite signal is absorbed by rain and no increase in antenna size will raise availability. However, the best way to reduce the effects of rain fade is toThanks.