Re: Space Geography

Roger replied to me:

> "Orbital inclination" is the term you're after here.

TomB: Yes. I wasn't sure what that inclination was relative too so I
avoided the term.

> Inclination of orbital plane relative to the ecliptic, which is what
you
> described in 2), isn't the same thing as eccentricity.

TomB: I meant eccentric in the sense of 'not conforming to the common
way'
versus mathematically eccentric orbits. Sort of how you might describe
an
eccentric Englishman. :0)

> But all the planets' planes are within 7 degrees of Earth's orbit, and
> all except Mercury within about 3.5 degrees. To a first approximation,
> the smaller the body, the more inclined its orbit is likely to be -
> Pluto's at 17 degrees, Pallas at 34, Eris at 44.

TomB: That gives me a reasonably idea for Earth's system. What I'm sort
of
wondering is if this sort of data is readily available from an online
catalog
of any sort. (By readily, I also mean 'without mind bending math tools
to
apply to the data').

> >Would that sort of approach help? Does background clutter matter?
>
> With realistic sensors, yes, but to a limited extent - remembering how
> sparse real-life asteroid fields are, unless you're willing to bury
your
> ship in a comet and wait for several years, it _is_ going to be
spotted.

TomB: I'm not talking about hiding behind planets or comets, although
those
sorts of things are valid. I'm talking about using background radiation
from
the systems of your galaxy and perhaps from bodies in your system to
make
it harder to pick you out.

TomB: Further assumptions:
1) FTL is Hyper
2) FTL system entry is 100D or some other lengthy distance away at
minimum
3) FTL exit can be detected reliably close in, less reliable further out
4) FTL exit can preserve speed, but exit vector direction can be chosen
5) Any stealth approach would preclude much braking until you had gotten
as
close as needed, therefore zero-zero intercepts with a body are not
required.
You want near distance passes at reasonable speeds for engagement. Or
for
recce with no engagement and a drift out.
6) Hull camouflage that can replicate the pattern of what is behind you
in
some or all spectra is feasible but perhaps subtly off perfect
7) Heat signature can be masked if not thrusting or firing but only
for a limited
time (hours, days, maybe a week max)

TomB: In assessing what a ship can pick out vs. the background, there
would
be questions of:
a) sensor transducer capability
b) sensor array capability (assume you are not just using one sensor)
c) sensor system data synthesis capacity
d) rate the system can scan a volume of space (may not be all that fast)
e) computer processing power backing up the sensors
f) how detection changes if the crew are not on alert (are they running
the
full deep scan or not)
g) ship's own desire to remain hidden or not

TomB: How fast would you have to come in ballistic to close from 100D
without detection if your hull stealth and thermal masking only lasted
several
days? Is it a practical speed? Does a masked hull stand a chance of not
being picked up by a sweep by a typical sensor array? Lots of
assumptions
to make, but important to understand if you want to understand how a
conflict
would play out. What is and is not possible will govern strategy and
tactics.

--
Only solitary men know the full joys of friendship. Others have their
family; but to a solitary and an exile, his friends are everything.
-- Willa Cather (1873 - 1947)Solitudinem fecerunt, pacem appelunt
-- Publius Cornelius Tacitus (from the book Agricola, attributed to a
speech from Calgacus)