Programmes cut off due to hot weather
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.