Monday, October 15, 2007

The jamming signal increases its hum

The story that Israeli satellite TV viewers have been experiencing constant interference for several weeks is an interesting one. As has been pointed out, it can't be the jamming presumably employed during the Deir ez-Zor raid, which would have been over weeks ago. According to the Israeli government it's all the fault of the Germans! More specifically they claim it's the air warning radar on one of the German (or perhaps Dutch) ships in the UN task force off Lebanon. Well, perhaps. Warships have been known to do weird things with radio in the past; but it's not as if they never exercise the radars in the North Sea.

There's more detail at Flight International; specifically, it's the Amos 1 and 2 birds, located at 4 degrees West.

I wonder if it had anything to do with this story from April this year? (I'd link to my own report on it for MCI, but their website is still very ungooglable.) The summary is that the pan-Arab satellite operator Thuraya, whose satellite mobile telephony and data service is found across the Middle East, Central Asia, and Africa, had been experiencing serious radio interference for most of 2006.

Intensive efforts to explain it failed; management blamed Israel, but eventually, the engineers decided to have the satellite revolve slowly around its axes in orbit while they logged the strength of the interfering signal. Essentially, it was the same way they used to do radio direction-finding by hand back in the day; that is to say, the second world war. Knowing its azimuth and elevation relative to the satellite, and that it would be coming from a point on the side of the earth facing it (and thank God it wasn't coming from the reciprocal..), they were therefore able to plot the source of the signal on a globe. It was somewhere in the Libyan desert.

Two engineers flew to Libya at once and headed for the lat and long position; not very surprisingly, they were arrested by machine gun totin' secret police agents before reaching their goal. Which seemed to lurk somewhere in an antenna farm surrounded by wire and goons and cameras and the like. Case closed. Eventually, the UAE ambassador to Libya secured their release.

It turned out the Libyans were having trouble with Touareg rebels and smugglers and bandits way down south, who tend to pack a Thuraya unit next to their Kalashnikovs; after all, at least one of the groups has got a blog to look after. But this is where it gets, well, Libyan; Libya is one of the countries that jointly own the Thuraya system. They are a shareholder. But for some reason they decided just to point a big dish antenna at the satellite and start frying pigeons.

There have been reports over the summer of disruption to Thuraya and also INMARSAT BGAN satellite-IP service in the Middle East, which could well explain it. Thuraya's satellite is stationed at 44 degrees East.

1 comment:

Trubes said...

Ranter; Totally off subject, did you get to Turkey and how was it ?

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