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 k8bl@ameritech.net 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 tjjapha@earthlink.net To: amsat-bb amsat-bb@amsat.org 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
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