[amsat-bb] Re: Malaysian airliner puzzle

[Tom Busch]

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 at 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 at earthlink.net>
> To: amsat-bb <amsat-bb at 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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