inmarsat

The other complication is that Inmarsat up-link is a steered spot-beam ( the antenna on the aircraft is stabilsed and driven, or phased-array in recent implemenations ).

Why is there no information about the Inmarsat and Iridium networks that a lot of aircraft already use?

Hopefully, Inmarsat has it right, and the black boxes will be found before their beacon batteries run out.

In contrast, since MH370, Inmarsat has changed the time period for handshakes with their terminals from one hour to 15 minutes.

GOE systems like Inmarsat don't reach every spot on earth, like the highest 30 or so degrees of latitude, or valleys.

As an interesting aside, Inmarsat are based on the Old Street roundabout in London.

Brochures I saw years ago indicated that least some portable Inmarsat terminals are also directed beams.

Apparently, Inmarsat also has an accurate read of the plane's transmit frequency.

This recent article casts some doubt on the Inmarsat analysis.

Of course Inmarsat will encourage airlines to implement this.

Apparently, Inmarsat had available accurate ping timing data.

Apparently it was hourly and Inmarsat calculated two arcs (north and south) which it could have taken, but then focus seems to have moved to the southern one in last few days.

There was another instance of this a few days ago with the article "How British satellite company Inmarsat tracked down MH370" [1].

Inmarsat is a "bent pipe" system, meaning that the satellite just amplifies and sends down to the base station everything that it receives.

Then the writer devotes hundreds of words to apparently tearing apart Inmarsat's attempt to estimate the plane's course.

However, all he is really saying, at great length, is 'Inmarsat won't show all their data to me or my sources'.

Their situation is easier than with Inmarsat, because Globalstar uses fast-moving (relative to points on Earth) LEO satellites rather than geostationary satellites.