TV reception in the Shanghai has been affected by a so-called sun outage, which occurs when the sun, the earth and a satellite are aligned.
The phenomenon began on February 28 and will last until March 28, according to the State Administration of Radio, Film and Television.
"When it happens, all satellite TV signals will be cut right off," said an official surnamed Du at Shanghai Cable Network Co Ltd. "But local television networks and out-of-town channels supported by cable or fiber technologies won't be affected."
He said since March 5, sun outages have hit satellites with links to Shanghai every day at about noon, and lasted an average of six to 10 minutes.
"But this year's outbreak is within normal scope," he added.
When the sun appears directly behind a satellite, ground antennas' communication links, like cable television, may be disrupted by the sun's RF energy.
This happens during the Vernal and Autumnal Equinox. The outages are brief and tend to occur over the course of several consecutive days.
An outage's duration depends on the frequency of satellite's operation, the size of the receiving antenna and the location of the earth station.
For instance, the phenomenon began affecting Beijing as early as February 29, and in cities like Haikou in the southernmost Hainan Province, it started on March 8 and can last until March 16.
"Communications stopped several times in the past few years, owing to outages," said Zhai Yi, assistant manager of Oriental Securities Co Ltd.
She said stock market investors had been accustomed to periodic outages, which affect real-time stock quotes that are transmitted via satellite from overseas.
(Shanghai Daily March 9, 2004)
