Waikato Times

Programmes cut off due to hot weather

- Steph Rangi

The hot, calm weather has been causing morning television shows to cut out in Taupo¯ .

Over the past few weeks, users of Taupo¯ ’s terrestria­l TV services have noticed their morning breakfast shows are being interrupte­d and it’s all down to the recent spate of warm weather.

Because of the lakeside town’s extremely settled weather, the terrestria­l TV has suffered from atmospheri­c fading which has caused occasional loss of the TV programmes sent to the Taupo¯ transmitte­r site.

Terrestria­l television is a type of television broadcasti­ng in which the TV signal is transmitte­d by radio waves from the earth-based terrestria­l transmitte­r of a television station to a TV receiver having an antenna.

There are three ways in which television­s broadcast their programmes – freeview terrestria­l using regular TV antennas pointing at a nearby transmitte­r site on a hill, freeview satellite which is the same as freeview terrestria­l but it needs a satellite on the roof and the third is Sky TV, using a satellite and server subscripti­on.

The weather is affecting the freeview terrestria­l service.

Warren Harding, an engineer from Johnston, Dick and Associates Ltd in Auckland, said the problem is caused by a ‘phenomenon’ called layering.

‘‘[It’s] where the atmosphere has alternate warm and cold layers at different altitudes,’’ he said. ‘‘This causes the atmosphere to act like a lens to the incoming programme signal which can steer the signal away from the receive antenna at the Taupo transmitte­r site.

‘‘If it bends the signal too far, the TV transmitte­r loses the programme informatio­n and has nothing to broadcast which causes these effects.’’

Since the problem is in the programme delivery, and not the transmitte­r’s coverage area, it will affect anyone watching the Taupo¯ terrestria­l service.

Programmes in the early mornings or late evening are the ones that are affected most as this is when the temperatur­es are beginning to change and causes the layers.

‘‘It’s not a problem of reduced coverage but that the transmitte­rs don’t have a programme to transmit during a fade,’’ Harding said.

During a fade, viewers may see ‘‘freeze frame’’ where the picture looks more like a snapshot than a video.

Other symptoms include ‘‘pixelation’’ where the picture turns into large coloured blocks because there’s not enough informatio­n coming in to display the full picture. In extreme cases a total loss of signal may be experience­d.

Due to the exact characteri­stics of the link equipment, the radio path, and the local weather it’s only television­s in Taupo¯ that are experienci­ng the disruption­s.

Harding said the situation is unavoidabl­e but services will return to normal if the weather systems stir up the atmosphere a bit.

 ??  ?? The recent spate of warm, calm, weather is having an impact on TV viewing in Taupo¯ .
The recent spate of warm, calm, weather is having an impact on TV viewing in Taupo¯ .

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