I would think by 2183, based on some current satellite sizes, a GPS
constellation which would offer decent coverage to most of the planet for a
period of months to a year could be
deployed using semi-disposable satellites that
are about the size of a small desk with their antennae arrays folded (or
motorcycle). You'd probably need between 24 and 70 of them. I'd expect a ship
with an experienced crew and shuttles to lay these could have these up and
running within 2-7 days. This requires localized
space superiority to do practically. Because you can also use the tactic of
deploying 700 even smaller satellites and therefore can stand losing a fair
number before service is significantly degraded (this is something that has
been considered in several areas of satellite service), it is possible to
construct (in theory) a cheap network with high redudancy.
If a major invasion was planned, as soon as effective local space supremacy
was achieved a modified freighter (fleet auxilliary) would deploy multiple
cargo shuttles each carrying 5 ot 6 of these sattelites and I'd imagine they
could be
placed fairly rapidly (say 1 every 4-6 hours).
With the smaller satellites, you'd deploy more of them faster as you don't
need to move as far
between deployments. With good auto-
deployment systems, this should also be a fast process.
Now, GPS will only tell you where on the globe you are. To add all the terrain
mapping, etc may require some larger satellites to be in place, but I'd assume
most Core, Inner and even significant outer colonies would be surface mapped
to 1m or less accuracy. I'd assume smaller outer colonies, outposts and
whatnot would often have only the mapping done by survey ships and extra
information about the
landing/settlement sites, so their would be
more work to be done if one wanted to use terrain data in outlying areas
(giving the locals a region to retreat to that the enemy wouldn't have good
data about).
But, that's all IMU.:)
T.
On Sun, 12 May 2002 18:01:09 -0400, "Thomas Barclay" <kaladorn@magma.ca>
wrote:
> I would think by 2183, based on some current
I would think that by 2183 it would be possible to put together a sufficiently
sensitive and accurate device to let you know your precise location that GPS
wouldn't be necessary. It would have to be able to detect its motion in all
three directions, not emit a signal that could be detected by sensing gear,
and be small enough to carry in the palm of a hand. While such a device would
be difficult to build now, I suspect it won't in 180 years, making the
satellite based GPS unnecessary.
On the other hand, if you are doing extensive operations on a planet you'd
probably need some sort of communications network in orbit, at which case
TomB's idea of a GPS network would be accurate.
I'm sure I'm labouring under a few incorrect impressions, so someone around
here who is in the know can clear things up:
1) Has not GPS (civilian side) been given up to some sort of open system? (If
so, wouldn't futzing up parts of it be problematic?)
2) Can differential GPS (multi-receiver) defeat or
significantly attenuate the futzing up signal? (That is, can't differential
GPS be used in such a way as to amerliorate the effects of signal uncertainty
introduction)? If so, the only receivers that will be seriously futzed by the
fuzz that can be inserted (fuzz substituting for any real technical
understanding....) would be
the non-differential single receiver GPSes,
correct? (And yes, these are the more common variety IIRC)
3. If the US (or anyone) were to fuzz up a signal coming from someplace and
this caused some manner of disaster (air crash, ship to run aground and sink,
etc), wouldn't that be a very bad thing? (Yes, I know secondary navigation
methods are meant to verify positions, but people ARE becoming GPS dependent).
I realize when weighed against a large scale offensive, these risks are
minimal, however I can see someone attempting some form of litigation... (Land
of the Free, Home of the Lawyer)
Thanks for any clarification or any correction.
Tomb.
Thomas Barclay schrieb:
> 2) Can differential GPS (multi-receiver) defeat or
I am not sure about differential GPS being used to correct distorted signals.
My guess is that it's possible.
The differential GPS schemes I am aware of all require a fixed reference point
or terrestrial GPS sender of known location. This implies limited range
(covering say, a city, port or airport). Thus it is not too relevant for
military operations, though it could be useful in street fighting. Taking out
differential GPS antennas might be as relevant an aim as other communication
devices.
> 3. If the US (or anyone) were to fuzz up a
Interesting thought. Certainly the GPS distortion cannot be aimed to be
limited to, say, Iraq. Other countries in the area might be affected
(including allies such as Israel or Turkey), as well as international air
traffic in the region. Air traffic disruption (even without accidents) might
be enough to have the airlines calling for help from the government.
Greetings Karl Heinz
> Thomas Barclay wrote:
I'm not sure what you mean by "open system". The GPS system's always been
pretty open, at least the civilian side.
> 2) Can differential GPS (multi-receiver) defeat or
Yes. However, both the mobile and stationary receivers have to have one or
more satellites in common. The correction is on a
satellite-by-satellite basis, so the more you have in common the better.
> If so, the only
Yes.
> 3. If the US (or anyone) were to fuzz up a
I wouldn't be surprised if the legislation that funds the GPS system --
and pays for the civilian side -- doesn't exclude the government from
damages. The government's funny that way...
> I'm not sure what you mean by "open system". The GPS system's always
When first out, the errors in position using civilian GPS could be quite
large, particularly in terms of elevation, all due to the futzing of the
signal by the military. Now, even the standard receivers are much better, as
the military have relaxed the rules somewhat.
> 2) Can differential GPS (multi-receiver) defeat or significantly
Which is almost a given, as the fixed reference point changes with locality
anyway.
As for usage of GPS, when my father in law to be can plot a course for the
yacht using his computer, and the thing can steer itself through the channels
in the Port of Miami and down to the Keys, or across to the Bahamas relying on
the laptop and the boat's differential GPS system (two receivers and a
reference station in South Florida), then the system can no longer be futzed
up too badly.
For a really basic description of GPS:
http://www.garmin.com/aboutGPS/
Currently civilian GPS is about the same accuracy as military GPS (about 3m)
but when SA (Selective Availability) was active the accuracy for civilians was
100's of m to 1.5 km. The military turned off SA a few years ago.
The military reserves the right to add SA whenever they wish as GPS is a
military system which they happen to allow civilians to use. As it is a US
military system it makes our European Allies a bit nervous and they are
setting up their own GPS satellite network.
Differential GPS depends on known land sites to send out GPS signals -
effectively becoming another GPS satellite, however they are limited by radio
range to be effective. Such locations would be known or easily discovered and
could be knocked out in a war, since they have to transmit to be effective.
Who says military research doesn't have civilian applications?:)
--Binhan
> -----Original Message-----
> John Sowerby wrote:
As I understand it, they simply quit adding the intentional noise. Now you're
stuck with just natural noise.
> As for usage of GPS, when my father in law to be can plot a course for
> the yacht using his computer, and the thing can steer itself through
Well, not without warning, at least. They can also add noise only in
certain areas -- so they could mess up civilian GPS over the Middle East
and leave the Bahamas alone.
> B Lin wrote:
> Differential GPS depends on known land sites to send out GPS signals -
Actually, before SA was turned off, there were a few sites that made
differential GPS information available through the Internet. Not very useful
unless you had a satellite or two in common with one of those sites, but...
> 1) Has not GPS (civilian side) been given up to
In the last year of Bill Clinton's administration, he finally authorised the
de-activation of the "dither factor" - random mathematical errors that
were
purposefully generated to throw a margin of error into the GPS network -
military GPS units with the correct on board tables could filter these out,
precision units (Airlines mainly) had different tables to give a greater
accuracy and standard civilian units had no correction - all this did
was
make sure that a non-US friendly user couldn't get firing solutions
based on GPS, nut could still get general use.
> 2) Can differential GPS (multi-receiver) defeat or
Differential refers to both multi-reciever (rare outside university
work)
and units that refer back to surface based beacons for higher accuracy -
they have a limited range and are still in use in some areas - coverage
was mainly restricted to areas where coverage was vital (airports) or no other
nav data was available (remote straits and passages). This system gave a finer
solution to both precision units and civilian units but no significant
improvement to military units. Additionally the system is affected heavily
by weather and the recievers' surrounding terrain - particularly
canyons.
> 3. If the US (or anyone) were to fuzz up a
The impact of such a move would theoretically mean quite a lot of property
damage, lots of lives lost and many, many law suits - you are very
correct
in the view that we are becoming GPS dependant - I sell and maintain GPS
units in Australia and even our taxis are co-ordinated by GPS.
> I am not sure about differential GPS being used to correct distorted
Correct - sort of, the DGPS setup did give additional information (if
you
have the beacon adaptor) to civilian and precision units - US friendly
forces gain little if any benefit.
> The differential GPS schemes I am aware of all require a fixed
Spot on!
> > 3. If the US (or anyone) were to fuzz up a
> Interesting thought. Certainly the GPS distortion cannot be aimed to
Too true - World court at the least - US Supreme court more likely
G'day,
> Interesting thought. Certainly the GPS distortion cannot be
Unless they have to land in one of those areas, you get redirected WAY around
the area (out of harms way and GPS problem area I'd say). 4 hours
flight time was added on the UK-Australia route during the Gulf War and
3 hours during the Russian coup.
Cheers
> Currently civilian GPS is about the same accuracy as military GPS
Garmin/GME would like you to think so - the average accuracy is about 5
m in
real life with a civilian unit - both precision and military units have
greater accuracy levels and even then the qualityu of the unit plays a big
part.
> The military reserves the right to add SA whenever they wish as GPS is
EGNOS - European Geostationary Navigation Overlay Service - it will not
replace GPS, just augment the existing service for civilian and precision
units and then help in the event of the return of SA. The US already has a
similar system called WAAS. (EGNOS should be operational by the end of 2003).
> Differential GPS depends on known land sites to send out GPS signals -
HARMS will do the job nicely.
http://www.millenniumsend.com/?page=resources§ion=resources
Has an essay on GPS. Might answer some questions and is written for
roleplayers so very little tech talk.
[quoted original message omitted]
A very interesting article about the EU system and the issues the Pentagon has
with it.
http://www.wired.com/wired/archive/10.08/airwar.html
> On Wed, 4 Sep 2002, Ryan M Gill wrote:
> A very interesting article about the EU system and the issues the
Or inversely, the problem the EU has with Pentagon policy....
Cheers,
> At 6:58 PM +0200 9/4/02, Derk Groeneveld wrote:
Well, in to paraphrase John Ringo, "there's always the whining European
faction". Still, the latter is a given when the former is ever related to
something involving foreign policy.
> A very interesting article about the EU system and the issues the
> faction". Still, the latter is a given when the former is ever related
Problem is that in this case, the EU version of GPS is going to be a much
needed product. Let's face it, the GPS satellites will fail at some time, and
having a second system up there will provide a much needed safety net when
that does happen.
I am staggered that the US has got so blase about international standards that
it appears that the Military ride roughshod over standards of bandwidth, and
that their signals will 'slop over' (wired's own term) into the frequencies
given by the International Radio Frequency panel.
> --- Derk Groeneveld <derk@cistron.nl> wrote:
Or, the simple fact that undoubtedly the systems will be sold to parties that
should NEVER have access to precision information like that. Like Iraq, Iran,
or some of the other places of "enlightenment" in the world. Giving potential
enemies a leg up is a traditional thing for some of the European nations to
do.
> At 2:32 PM -0400 9/4/02, John Sowerby wrote:
Not that the spare GPS birds in orbit will provide spares for a failed sat.
> I am staggered that the US has got so blase about international
Not that France has much to say with 802.11b occupying one of their prime
military frequencies. Anyone can locally jam French Military Coms with an
iBook and Airport Card.
> On Wed, 4 Sep 2002, John Hamill wrote:
> Or, the simple fact that undoubtedly the systems will
*snort* *chortle*
Who supplied the Taliban before they became enemy? Who supplied Iran befor
they became enemy? Who supplied Iraq when they were the enemy of Iran?
In all cases the US is amongst the list.
Anyway, this doesn't belong on this list, but I could not let this go
unanswered.
Cheers,
> On Thu, 5 Sep 2002, Derk Groeneveld wrote:
> Who supplied Iraq when they were the enemy of Iran?
Hmmm. I may actually have to withdraw that last one as I can't think of actual
equipment that was so supplied by the US. I still feelquite sure of it but
without supporting evidence please ignore it. My response with respect to Iran
and Taliban still stands, though.
Cheers,
> --- Derk Groeneveld <derk@cistron.nl> wrote:
If you mean in the 80's when the Mujahadin were fighting the Soviets, that
would be true. However, the Taliban as they existed were not being supplied by
ther US, on the contrary, their enemies were getting some (very) low level
assistance from the US. The Taliban got much of its money from very
conservative Muslims accross the world, including the Saudi's. Indeed much of
the religious training that "inspired" the Taliban came from Wahib religious
schools, set up by the Saudis. Plus the fact is that ALL of the Taliban's
equipment is either Soviet, European, or
Asian in manufacture,no Ford pickups, M-16's or M2HB
on the streets of Kabul, just your average AK's, Fal's and Toyotas.
> Who supplied Iran befor they became enemy?
That point is given, before the Shah fell, the US supplied him with lots of
weapons and equipment. However, just where did the Ayatollah Khomeni reside in
exile? Where did he plan the coup, organize his backing, and finally overthrow
the Shah? Why, France, of course. Without the tacit acceptance of the French
and others in Europe, he wouldn't have been as much of a problem.
> Who supplied Iraq when they were the enemy of Iran?
As I recall, even during the time that Iraq was fighting with Iran, the vast
majority of the weapons systems used by Iraq were either Soviet or European,
with the Soviet equipment ahead by a wide margin. And as far as supplying
Saddam with "toys" wasn't it a French nuclear plant the the Israeli's bombed?
And I think it was German and French companies who built his chemical plants,
right? And his bunkers, they were built by a German company weren't they? (The
only good part about this was that, being Germans, they kept very good records
of plans and locations of the bunkers, which helped when it was time to take
them out)
> In all cases the US is amongst the list.
On the list but, with the exception of pre-Ayatollah
Iran, not even near the top of the list. It annoys and amuses me that post
WWII Europe plays this game of running around the world, buying and selling
with various shady types, then pointing fingers at either the US or Russia
when things go bad, like they never had anything to do with it.
> Anyway, this doesn't belong on this list, but I
The modern discussion may not, but I imagine the same types of things go on
between ostensible allies like the ESU and FSE, or the NAC and NSL, where the
economic concerns of the one do various snarky things the the foreign policy
of the other. It would be interesting to see how much cooperation there really
exists between erstwhile allies such as the ESU and FSE.
> Cheers,
As always YMMV,
That would be intelligence data and some funds supplied to the Iraqis, not
actual stuff. They then used the data to plan chemical warfare attacks on the
Iranians. Which we knew they would be doing. Which makes us accessories at
best and conspirators at worst.
Saddam wasn't as surprised at Stalin was.
> Derk Groeneveld wrote:
> On Thu, 5 Sep 2002, Derk Groeneveld wrote:
> On Fri, 6 Sep 2002, John Hamill wrote:
> > In all cases the US is amongst the list.
Um. I never claimed europe was innocent. But claiming 'giving weapons to
people who shouldn't have them' is a traditional european thing is jsut rather
hypocritical as america has at least as much of a history of doing so.
In fact, for currwent military exports most european companies stick pretty
much to the US 'allowed export' guidelines. Before even going into ethical
issues there is a very practical reason for this. In the current world
economy, there are international parts in any product; including
american parts. And supplying things to black-listed countries is a very
quick way to make sure you don't get the parts you need, anymore.
Anyway, 'nuff said.
Cheers,