What is rain attenuation in satellite communication?
ABSTRACT. Rain attenuation is a major challenge to microwave satellite communication espe- cially at frequencies above 10 GHz, causing unavailability of signals most of the time. Rain attenuation predictions have become one of the vital considerations while setting. up a satellite communication link.
What is depolarization satellite communication?
Depolarization is an effect wherein a satellite link’s wave polarization is altered after being launched by the antenna. Some texts refer to depolarization as cross-polarization. Depolarization on a satellite can be caused by rain, ice, snow, multipath, effects, and refractive effects.
What is the effect of rain on the satellite link?
One of the factors that affects availability in a satellite communication link is rain. The presence of rain can have a significant detrimental effect on the propagation of an electromagnetic signal. The rain degradation increases as the frequency increases.
What are the basic elements of satellite communication?
Satellite communication has two main components: the ground segment, which consists of fixed or mobile transmission, reception, and ancillary equipment, and the space segment, which primarily is the satellite itself.
What do you mean by rain attenuation?
[′rān ə‚ten·yə‚wā·shən] (communications) Attenuation of radio waves when passing through moisture-bearing cloud formations or areas in which rain is falling; increases with the density of the moisture in the transmission path.
What is ionospheric depolarization?
Ionospheric depolarization: The direction of electron motion is no longer parallel to the electric field of the wave, and as the electrons react back on the wave, the net effect is to shift the polarization. This is referred to as ionospehric depolarization.
What is the depolarization in propagation of nerve impulse?
depolarization: a decrease in the difference in voltage between the inside and outside of the neuron. hyperpolarize: to increase the polarity of something, especially the polarity across a biological membrane. node of Ranvier: a small constriction in the myelin sheath of axons.
Why rain fade margin is important in satellite communication?
As more and more constellations go online, reliable communication between satellites and receivers on the ground will become ever more important. Rain fade can impair signal transmission and reception, and cause temporary degradation in radio frequency communications.
What are the uses of communication satellite?
The purpose of communications satellites is to relay the signal around the curve of the Earth allowing communication between widely separated geographical points. Communications satellites use a wide range of radio and microwave frequencies.
How is rain attenuation used in satellite communication?
On most satellite links above 10 GHz rain attenuation limits the availability of the system and to develop an adequate link margin, the rain attenuation to be expected for a given time percentage needs to be calculated.
Why is convective rain important for satellite communication?
Convective rain is generated by vertical air currents that can be very powerful, leading to thunder storms and high rainfall rate. Convective rainfall is very important for satellite communication system, because it is the major cause of link outages.
Which is a measure of the effects of polarization?
Cont… Cross-polarization discrimination (XPD) One measure to quantify the effects of polarization is called the cross-polarization discrimination (XPD) Cross-polarization discrimination observations – rain depolarization. Looking at XPD as a function of the co-polar attenuation (A), it can be concluded that:
How is the sense of polarization of an antenna defined?
The sense of antenna polarization is defined from a viewer positioned behind an antenna looking in the direction of propagation. The polarization is specified as a transmitting, not receiving antenna regardless of intended use. We frequently use “hand rules” to describe the sense of polarization.