Saya mengalami pada malam minggu kira-kira 12.30 tghmalam tengah siok-siok
tengok bola...nda hujan nda ribut tiba-tiba no signal...


>From: "Hazarry Haji Ali Ahmad" <hazarry@...>
>Reply-To: bruastronomy@yahoogroups.com
>To: <bruastronomy@yahoogroups.com>,<falak-net@yahoogroups.com>
>Subject: [bruastronomy] Apabila ASTRO "Solar outage"
>Date: Sun, 25 Sep 2005 19:36:56 +0800
>
>Ada sesiapa yang tengok astro tadi petang kira-kira jam 2. Banyak channel
>yang tergendala dan signal gagal di terima, dan lepas tu ada message
>tertera mengatakan "Solar Outage". kurang dalam 1 minute baru signal
>kembali pulih.
>
>So apa dia Solar Outage?
>Source: http://www.selkirkshire.demon.co.uk/analoguesat/outages.html
>
>
>Solar Outages
>
>
>
>What are they ?
>
>In March / April and September / October day and night are about the same
>length. At these times of year the sun crosses the equator and it traces an
>arc that places it directly behind the broadcast geostationary satellites.
>
>This can cause a strange phenomenon known as a solar (or sun) outage. This
>is a disruption to satellite reception for a few minutes each day for a few
>days. The exact date, time and duration of such events depends on the
>receive site location, the satellite in question, the size of the dish on
>your house, the station keeping accuracy of the satellite and how accurate
>your dish points at the satellites.
>
>As these events can be accurately predicted for each satellite, the events
>are announced well in advance. In recent years, I have seen the BBC Weather
>service advising viewers that an outage is likely. An outage only ever last
>for a few minutes, since the Sun continually tracks round its orbit. After
>a few minutes, the Sun moves on past the satellite, and your pictures
>re-appear.
>
>
>
>What causes it ?
>
>Solar Outage results because the sun is a powerful broadband microwave
>source and has a noise temperature well in excess of 25,000 degrees
>Celcius. As the sun passes directly behind the satellite (when viewed from
>earth), reception of the relatively weak satellite signals is affected. The
>degree of interference varies from slight signal degradation to complete
>loss of signal as the downlink is swamped by the noise from the sun.
>
>An outage may last several minutes each day during the interference season
>and will last longer the smaller the antenna involved. A 40cm dish will
>have a longer period of interference than a 120cm dish. This is because a
>small dish has a greater signal acceptance angle than a big dish.
>
>An outage event can occur for several days both before and after the peak
>day. Outages will occur at roughly the same time each day and may repeat on
>a daily basis for a week or more.
>
>
>
>Data amaran Solar Outage:
>http://www.pesat.net.id/info/Solar%20Outage%20Y2005-Agila.htm
>Other definition:
>http://www.geo-orbit.org/sizepgs/Noise.html#anchor4293062540
>

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