Satellite Communication Book By Dc Agarwal Pdf Download ((INSTALL))

S. A. Engels learned that he could find the strengths and weaknesses of the satellites by looking at the arrive times. In the first place, he found that the same strength that permitted the satellite communication reduced the traveling time. It caused the signal to arrive no faster than it would have in the absence of the satellite. A flaw in the satellite code�s operation, then was the cause of the delay.

The principle was found to be applicable for almost every transmission between two points. The signal received from a satellite contains both the signal itself and the shifts created by the path through the ionosphere. If the strength of the satellite signal is high, the ionosphere-created shifts are weak. This allows the rocket to be launched at a time when the ionosphere is relatively calm and stable. If the satellite signal strength is low, the ionosphere-created shifts grow. This is especially true if the transmission is over longer distances or through more atmosphere than a rocket can pass.

Still, he discovered that there were several weak spots. The first was if the satellite spends a long time at a single location. The changes in the ionosphere can then be greater than expected. He found that this is caused by a phenomenon called scintillation. The light waves turned around in the atmosphere effect becomes greater. The result is a number of components of observer ĂĽs telescopeã. The light arriving from a nearby direction is focused into much smaller volume. Once the last component undergoes a change of direction, it travels. If the change of direction happens frequently, then the aligned light wave becomes focused into a single point. This causes a loss of signal strength.

The second factor that reduces signal strength was turbulence. The usual path of the satellite is through a calm atmosphere. The turbulence is typically caused by natural waves or by clouds. It creates an unknown effect that reduces its strength.

Finally, if the satellite is close to the earth and its orbit is geostationary, the receiver automatically set its field of view to look out in all directions. This is called mechanical scan. In this case, that field is returned to look out in the direction of the satellite. d2c66b5586