Mumbai University > Computer Engineering > Sem 6 > Mobile Communication & Computing

Marks: 4 Marks

Year: Dec 2016

A satellite doesn't necessarily have to be a tin can spinning through space. The word "satellite" is more general than that: it means a smaller, space-based object moving in a loop (an orbit) around a larger object.

The Moon is a natural satellite of Earth, for example, because gravity locks it in orbit around our planet. The tin cans we think of as satellites are actually artificial (human-built) satellites that move in precisely calculated paths, circular or elliptical (oval), at various distances from Earth, usually well outside its atmosphere.

Following are the problems of satellite signals travelling from a satellite to a receiver:

1. The problems are attenuation of signals caused by the atmosphere, dust, rain, fog, snow.
2. Depending on the elevation, the signal has to penetrate a small or larger percentage of the atmosphere.Generally an elevation less than 10 degrees is considered useless for communication.
3. Blocking of signals due to obstacles (buildings, mountains).
4. The lower the elevation the longer is the way for the signals through the atmosphere, thus high output power is needed