Friday, August 5, 2011

When the universe hates rubgy

Those who rely on satellite links for data or television signals are only too familiar with the effect of atmospheric effects on the signal they receive.

When heavy rain, thick cloud or, on occasion, even dense fog is around, the minute amount of power that would normally reach their satellite dishes and be focused onto an ultrasensitive LNB sometimes is just not enough to allow the signal to be separated from the noise.

This is usually a transient problem and occurs so infrequently as to be little more than a minor annoyance -- however, another, more celestial effect looks set to wipe out some parts of the Rugby World Cup broadcasts carried by satellite TV provider, SkyTV.

According to reports, some outages of up to 15 minutes will affect live coverage of some rugby games during the RWC competition and this time it's not atmospheric conditions that are to blame.

The culprit will be the sun itself.

Due to the geostationary orbit of the satellites which carry some key data and television signals, twice each year the positioning of those satellites just happens to be such that they eclipse the sun itself. Or should I say "try to eclipse" the sun.

Unfortunately, since their size is so much less than that of the sun, our neighbourhood fusion reactor effectively obliterates their signal by outshining it with a blast of electromagnetic radiation many orders of magnitude greater than the satellite's faint signal.

When these satellites are positioned directly between the sun and the receiving dishes on the earth below, the radio frequency noise that the sun generates effectively overwhelms the comparatively feeble satellite signal and thus reception is lost.

What's worse is the fact that the larger the satellite dish being used, the worse the effect, as an increasing amount of the sun's "noise becomes focused on the sensitive LNB at the focal point of the reflector.

This effect usually only occurs for a few minutes per day over a period of several days, around the spring and autumnal equinoxes but unfortunately, this year the spring equinox coincides with the RWC and the timing of some of the matches being played as part of that competition.

Broadcasters say the worst effects will occur at around 1:20pm but will be relatively short in duration, affecting viewers in some regions more than others.

However, it just goes to show that no matter how advanced the technology, mother nature always has the final say.

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