> Some esteemed lister wrote:
A simple, and modern, example is GPS. Something (relatively) far away, and
used every day to predict where on earth (and near Solar system as well!) you
are. I personally have used a GPS unit to determine where I'm going, where
I've been, and where the hell I am right now.
[Tomb] Assuming that the US is not
invoking the special protocol it has in place to introduce errors (either
localized or system wide) in the location information.
[Tomb] Re: space nav - why is locating
yourself either/or? You'd use visual, other-
spectra, pulsars, etc. all to locate your
position - whichever you could locate
nearest and sufficiently distinctly to uniquely place yourself. Probably which
method was easier or faster would depend on a number of factors and no one
factor would be determinist. You'd have multiple methods to locate yourself
and you'd use stellar objects which had fairly unique signatures where
feasible.
Here's an interesting follow up: How long do we think it would take for a
starship to fix position: a) In deep space b) In a known planetary system c)
In an unknown planetary system (but near a star that probably is cataloged
somewhere)
[Tomb] Regarding the roughness of space
transit, the presence of human colony ships or military ships or merchant
ships tells us nothing about the short term post jump effects. It merely says
that any long term jump stresses can be avoided by 6 hour layovers or are
sufficiently slow as to be acceptable (maybe increased risk of neurological
disease, etc). For all we know, jump is terribly rough, but the humans
compensate with drugs, regenerative
technology, or some kind of mini-stasis
field. You could be violently ill for an hour after jump. Who knows? As long
as it doesn't have seriously and rapidly onsetting deleterious effects that
are persistent, the kind of universe described in the game could exist. It
could also be that if you push your jump intervals, the effects accumulate
(think tough ride for couriers or mercy missions).
My thinking was 6 hours was the "low stress option" which would allow you to
jump continously for a fairly long time. Faster cycling would lead to
accumulated jump stresses. And that military crews had methods to cope with
this better than civilian crews and part of the selection process involved
resilience to this phenomena. The way I envisioned it, military crews could
push for up to four jumps a day, but most civilian ships would be happy with
2. To make reasonable (but
still non-instant) travel times around the
universe of GZG as depicted by Nyrath the Indispensable, Stellar Cartographer
to the GZGverse, I think I set the maximum jump at 7.7 ly. I made military
systems more capable than civilian ones, and travel in cold sleep safer. (This
justifies colony
ships, fish-stick marines, and lifeboaters
going to cold sleep)
I actually wrote some campaign rules for
this, but they're temporarily off-web thanks
to an ISP server dying in a most ugly fashion.
If there is interest, I can get the HTML page with my take on things back up
again fairly quickly.
[Tomb] One last thought: Deathworld was
written after Harrison visited Oz. He toned it down a bit for the novel.
> Some esteemed lister wrote:
A simple, and modern, example is GPS. Something (relatively) far away, and
used every day to predict where on earth (and near Solar system as well!) you
are. I personally have used a GPS unit to determine where I'm going, where
I've been, and where the hell I am right now.
[Tomb] Assuming that the US is not
invoking the special protocol it has in place to introduce errors (either
localized or system wide) in the location information.
[Tomb] Re: space nav - why is locating
yourself either/or? You'd use visual, other-
spectra, pulsars, etc. all to locate your
position - whichever you could locate
nearest and sufficiently distinctly to uniquely place yourself. Probably which
method was easier or faster would depend on a number of factors and no one
factor would be determinist. You'd have multiple methods to locate yourself
and you'd use stellar objects which had fairly unique signatures where
feasible.
Here's an interesting follow up: How long do we think it would take for a
starship to fix position: a) In deep space b) In a known planetary system c)
In an unknown planetary system (but near a star that probably is cataloged
somewhere)
[Tomb] Regarding the roughness of space
transit, the presence of human colony ships or military ships or merchant
ships tells us nothing about the short term post jump effects. It merely says
that any long term jump stresses can be avoided by 6 hour layovers or are
sufficiently slow as to be acceptable (maybe increased risk of neurological
disease, etc). For all we know, jump is terribly rough, but the humans
compensate with drugs, regenerative
technology, or some kind of mini-stasis
field. You could be violently ill for an hour after jump. Who knows? As long
as it doesn't have seriously and rapidly onsetting deleterious effects that
are persistent, the kind of universe described in the game could exist. It
could also be that if you push your jump intervals, the effects accumulate
(think tough ride for couriers or mercy missions).
My thinking was 6 hours was the "low stress option" which would allow you to
jump continously for a fairly long time. Faster cycling would lead to
accumulated jump stresses. And that military crews had methods to cope with
this better than civilian crews and part of the selection process involved
resilience to this phenomena. The way I envisioned it, military crews could
push for up to four jumps a day, but most civilian ships would be happy with
2. To make reasonable (but
still non-instant) travel times around the
universe of GZG as depicted by Nyrath the Indispensable, Stellar Cartographer
to the GZGverse, I think I set the maximum jump at 7.7 ly. I made military
systems more capable than civilian ones, and travel in cold sleep safer. (This
justifies colony
ships, fish-stick marines, and lifeboaters
going to cold sleep)
I actually wrote some campaign rules for
this, but they're temporarily off-web thanks
to an ISP server dying in a most ugly fashion.
If there is interest, I can get the HTML page with my take on things back up
again fairly quickly.
[Tomb] One last thought: Deathworld was
written after Harrison visited Oz. He toned it down a bit for the novel.
> [Tomb] Assuming that the US is not
Snip - bearing in mind that the "Dither Factor" was lifted in march 2000
-
most current civilian GPS units were able to defeat the protocols by
"positional averaging" and to a more limited method - DGPS beacons -
couldn't space nav assume similar "advances" by suitably motivated people?
[quoted original message omitted]
Tom,
Normally I let this veiled US bashing pass. The US can induce errors into the
GPS system due to the fact that the US conceived built and launched it. Is it
useful to the rest of the world? The US hopes so. Can anyone use it? Of
course. During a conflict if it is determined that a foe is using GPS data for
accurate targeting will the US decrease the
un-encrypted accuracy. Most assuredly.
As for the spoofing of GPS. It is based on a time error that will cause system
wide accuracy to decrease to approx 100m accuracy.
Magic
> --- Thomas Barclay <kaladorn@magma.ca> wrote:
> > Snip - bearing in mind that the "Dither Factor" was lifted in march
Am I
> talking about pulsars or GPS? I could see spaceships using pulsars as
Actually, the parenthetical statement is not correct. Otherwise, yeah, pulsars
will very likely be the primary means starships use to positionally locate
themselves between jumps.
Mmmmm Touch of American paranoia possibly. As far as I know the only
non-Americans who use GPS guided smart weapons are us Redcoats - and we
have the encryption key. Time to launch the NAC! John
> Normally I let this veiled US bashing pass. During a conflict if
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
It may be but I will stand up for my Country.
Magic
> --- John Lambshead <pjdl@nhm.ac.uk> wrote:
During peacetime the "spoofing" is kept to a minimum, so civilian GPS systems
enjoy a useful amount of accuracy. If America finds itself facing a foe where
our own GPS satellites may be used against us, the encryption key will change
(shared with allies of course) and the increase in spoofing will make it so
that a civilian GPS guides you to Antarctica before it guides you to that
perfect camping spot you marked
the co-ordinates for last year.
That part of the design was referred to as paranoia. My response to that is
that it's paranoia until someone exploits it. If you fail to have the paranoia
and someone exploits it, then it's called naivety. Nations can't afford
naivety.
--Flak
> On Fri, 2002-02-22 at 08:34, Robert Makowsky wrote:
Esteemed? Heh... Not the last time I checked.:)
Since the US is going to a new system, GPS should remain relatively stable
from now on out... At least for my use, since I don't generally go camping
when we're at war...
Space Nav... It's not either/or in general. Any system would and could
be used, IF it was effective.
Using stars, unfortunately, is not effective in all types of use. If you
already know where you're going to be, and you know the constellations as they
would appear to you, then using the "brightness" of nearby stars can work. But
you MUST appear where you predicted yourself to be. Otherwise, things won't
look right, and with 10s of 1000's of possible stars you could be looking at,
and could be closer to, without anything to uniquely point to, you're lost.
Navigation depends on unique and known points to reference yourself to.
Pulsar's give us both. They don't move relative to you, they are uniquely
identifiable, quick and easy to find (if you know what you're looking for),
and with plenty of them, you're accuracy for determining where you're at is
near perfect.
So to answer your questions: A) Either system would work, with stars carring
the caveat IF you know where you were going, plotted what stars you would
expect and what constellations you were looking for, and you actually get
close enough to the predicted point. Pulsars work no matter what, given you
don't leave the area they've projected thier radio waves at.... (Effectively
this galaxy, and possibly neighboring galaxies, but doubtful to much further
out.) B) Obviously either, if you actually make it there. Best possible
navigation aid here is system bound, something like a SPS (solar positioning
system), but even a GPS works system wide, IF the planetary diameter is wide
enough for the signals to have a discernable space between them (thus not
looking like a single point) at the distance you're at to them. Of course, you
can just point yourself at the signal and travel towards it until you can
differentiate signals. C) The answer A applies here as well...
Rand.
P.S. answers to last email are forthcoming, I promise.:)
> Thomas Barclay wrote:
> Some esteemed lister wrote:
> On Fri, 22 Feb 2002, Robert Makowsky wrote:
What's gotten into people today? Lots more bitching on the list that usual.
Slow down, people...
How is what TomB said 'veiled US bashing'? The US runs the GPS sat network;
anyone who's used GPS knows that the US can, if it feels the need, degrade the
accuracy of that system. Pointing this out counts as US bashing?
(Now, what happened to your Olympic women's hockey team last night -
*that* was US bashing in grand style, and in front of a Yank audience to boot!
Go Canada!)
(Here's hoping our men's team repeats the performance this weekend - as
I
write Canada is trashing Belorussia, 7-1 and it's not over yet! Double
hockey gold would be so cool!)
Brian - yh728@victoria.tc.ca -
- http://warbard.iwarp.com/games.html -
> As for the spoofing of GPS. It is based on a time
[quoted original message omitted]
> On Tue, 26 Feb 2002 15:17:50 +1100 Beth.Fulton@csiro.au writes:
I guess timing is everything.
And it *did* work, right?
Gracias,