Looks like I'm wrong. The "Steering" info wasn't from CNN. It's from this Huffington Post article: http://www.huffingtonpost.com/2014/03/16/malaysia-airlines-takeover_n_4972889.html. I still would like to know how the satellite knows.
It also says that these "pings" occur every hour, so I suppose it could have kept flying for an hour after the last contact. Tom WB8WOR On Mon, Mar 17, 2014 at 11:28 AM, Tom Busch <[email protected]> wrote: > The news has been reporting that they are using the angle of the last > known ping from the ACARS system to the satellite. This is where the > 40-degree arc around the satellite comes from. > > What I don't understand is how INMARSAT knows what that angle is. CNN > says that the satellite steers its antenna to the location where it expects > the next ping, but that doesn't make sense. > > I have been looking for the algorithm, but I can't find it. Signal > strength? Some sort of electronic steering? Trade secret? I don't know. > > Tom WB8WOR > > > On Sun, Mar 16, 2014 at 10:57 PM, R.T.Liddy <[email protected]> wrote: > >> Tony, >> >> They would use the time differential between receipt >> to measure the distance versus the location of the >> satellites. The more satellites, then the more accurate >> the triangulation. >> >> 73, Bob K8BL >> >> >> ________________________________ >> From: Anthony Japha <[email protected]> >> To: amsat-bb <[email protected]> >> Sent: Sunday, March 16, 2014 4:49 PM >> Subject: [amsat-bb] Malaysian airliner puzzle >> >> >> Thanks Rick, >> How do those sats determine distance to the source? >> Tony, N2UN >> >> --- >> This email is free from viruses and malware because avast! Antivirus >> protection is active. >> http://www.avast.com >> _______________________________________________ >> Sent via [email protected]. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> _______________________________________________ >> Sent via [email protected]. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> > > _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
