Re: SPS/Pulsars

"K.H.Ranitzsch" wrote:
> 
> ----- Original Message -----
> From: "Indy" <kochte@stsci.edu>
> >
> > And astronomers everywhere are going to pick up on it (esp those who
are
> > studying these sorts of things), chart it, catalog it, and could
possibly
> > figure out what it is/isn't. If it is determined to be close enough,
a
> > science expedition *might* be sent out to investigate "a close-up
pulsar".
> > In reasonably short order it will be determined to be a beacon
instead of
> > a real pulsar (assuming your original intent was to fool the
navigation
> > of another force) and word would get out. I really don't think
beacons are
> > going to be a viable way of nav-spoofing.
> >
> 
> Well, if the beacons imitate specific real pulsars in their
frequencies and
> repeat patterns, they could, at least over a limited volume, be made
> indistinguishable from the real ones and make navigation difficult.
Lots of
> similar cases from fake lighthouse to electronic warfare.
> 
> But the time lag seems a serious problem.

That and how do you disguise the real pulsar so it isn't picked up?
Moreover, I would think that unless you have rearranged where the
pulsars
are in space completely, a savvy nav officer is going to pick up on
any discrepencies when correlating to other known pulsars. With hundreds
to choose from, how do you know which ones will be picked for spatial
location purposes? Unless there is some very rigid protocol about
choosing
only a specific 3 or something. Personally, I'd have my navcomps be
picking as many as feasibly possible in order to really nail my position
down. Any rogue pulsar mimickers ought to stand out pretty plainly in
those instances.

Also, adding redundancy to the system, sanity checks by using remote
targets that won't change at appreciably no matter your location after
a jump would help for basic orientation (I'm thinking of objects like,
oh, the Andromeda Galaxy and the Large and Small Magellanic Clouds;
there would be other objects available for orientation purposes as
well).

Fake lighthouses and e-warfare operate in a much tighter realm than
that of using pulsars. It's that distance thing you have to overcome
when faking out a pulsar (and masking the real one; another daunting
task, I would imagine ;-)