Satellite Communication

Radiowaves

Radiowaves have a very long wavelength(1m to 10km). Different frequencies of radiowaves are affected by the Earths atmosphere in many different ways:

1.Some frequencies (30MHz-30GHz) pass through the earths atmosphere (relatively short wavelength.

2.Some frequencies (above 30GHz) are reduced in strength, or even stopped, by the earths atmosphere. They are absorbed and scattered by rain, dust and other atmospheric effects.

3. Some frequencies (below 30MHz) are reflected by a part of the Earths upper atmosphere called the ionosphere.

The same frequencies can't be used to send informatio to all types of satellites. Low orbitting satellies use low frequency signals. Geostationsary satellites are much further above the earth so they need to use high frequency signals.

Microwaves have a higher frequency and a shoter wavelength than radiowaves. THey are used to transmit information to orbittig artificial satellites, which then retransmit information back to Earth.

Difffraction

When a wave meets an obstacle, such as a hill, it will spread around the hill. If it meets a gap, it spreads out through the gap. This can cause the wave to be diffracted i.e spread out from the edges.

Different size gaps cause different amounts of diffraction, for example, if…