Re: Sensors

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On Tue, 29 May 2001, Richard and Emily Bell wrote:

> The nature of shipbuilding makes it impossible for two vessels of the
same
> class to be identical, and often minor improvements are worked into
the design
> as it is built.  The chaotic nature of turbulence also has a hand
here, so two
> nominally identical hulls will have similar, but distinctive
flownoises.
> Distinguishing between two passive contacts is not that difficult (not
that it
> is easy), and a tape library of previous encounters enables the
listener to
> identify a specific vessel.  Combine this with some other intelligence
(Sonar
> profile SN7 just went into port, and simultaneous pic of the Seawolf),
and
> passive sonar can tell you exactly which vessel has been encountered.
> 
> ESM will give a list of operating active sensors, this list is much
like a DNA
> test, in that it does not tell you which vessel, but does allow you to
rule
> some out.  Detecting an active SPY-1 informs you that the blip is an
area air
> defence vessel, with SM2-MR missiles, aplenty.  Not detecting an SPY-1
radar
> may simply mean that it is off.

Similarly, it's about impossible to rebuild EXACTLY the same frequency
control unit for a new radar etc. So sufficiently advanced ESM should be
able to tell you WHICH SPY-1 that is, once you have identified it
before... And assuming it's switched on.

Cheers,

   Derk
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