Adverse weather conditions have been known to affect the quality of the
satellite TV signal reception. This is popularly called "rain fade".
Usually, when this occurs, it is only for a short period of time.
In reality, heavy rains and cloudy conditions can affect television
signals enough to result in noticeable degradation of image quality.
In very severe cases, reception can be effectively disrupted. Factors
that determine how often this will happen include regional yearly
rainfall figure, location in the satellite footprint and height of the
satellite above horizon.
While it takes very
heavy rain to affect signal reception of a properly aimed and wired satellite
home system, still, it can and will occur where the conditions are present.
However, it is more
likely to occur more in areas with significant annual rainfall like tropical
Africa or South America, especially in countries where rainfall is preceded by
dense clouds or accompanied by strong storms. It is less likely in Europe and
certain parts of the US. Still, it happens, only less frequently.
The major cause of
signal degeneration is satellite wave absorption by the rain drops. There is
also some signal scattering, due to deflection of satellite communication
between one medium and another or interference between the wave forms produced.
But it is not only
rainfall that causes signal degeneration. Very heavy snowing can also affect
signal quality, but it is generally less likely to interfere.
Not all satellite
signals are affected equally. In general, the longer radio wave, the less
affected it is by the "rain fade". Transmission via the longer
C-band wavelength is significantly less susceptible to this kind of
interference than the one done via the shorter Ku-band (which is used by DStv)
or Ka-band.
Also, the farther off
central receiving area location, the more pronounced the effect of rain-fade
effect is.
Often, susceptibility
to rain fade is symptomatic of a less than optimally aimed dish.
Reception quality
also can be affected by water or snow/ice accumulating over the surface of a
dish receptor. This may result in scatter and less efficient focusing of the
satellite signal after its reflection from the dish surface.
Most often, a yearly
maintenance of the dish by a qualified maintenance hand will address this.
In temperate
regions of the world, a special dish with built-in heater is used to prevent
accumulation of ice.
Rain fade is neither
exclusive to Nigeria nor Africa.
