ARMS-D-Request@XX.LCS.MIT.EDU (Moderator) (11/11/86)
Arms-Discussion Digest Tuesday, November 11, 1986 12:06AM
Volume 7, Issue 56 (possible repeat, mailer screwup)
Today's Topics:
portable anti-tank weapons
Yet more on SDI (Star Wars flawed #7-of-10)
Re: Meteorite as A-explosion
Re: Unequivocal confirmation of detonation
SDI
New Isotope Enrichment Technique Discovered
Launch on warning / nuclear victory metrics
24 hour endurance for bombers
Re: Launch on warning / nuclear victory metrics
Friend-foe identification (from RISKS)
----------------------------------------------------------------------
Date: Mon, 10 Nov 1986 17:11 EST
From: LIN@XX.LCS.MIT.EDU
Subject: portable anti-tank weapons
From: drogers%farg.umich.csnet at umix.cc.umich.edu (David Rogers)
On the slightly dull topic of portable anti-tank weapons, does anyone
know about the (I believe) Swedish anti-tank weapon scheduled to
replace the LAW, the standard American light anti-tank weapon?
The Swedish weapon in the running is the AT-4, which is regarded as an
"interim" weapon until the Army can come up with its new tank killer.
Cost = $675 per unit. However, the AT-4 is classified as a light
anti-armor weapon, not an anti-tank weapon. As currently configured,
it can penetrate 450 mm of armor, enough for killing modern tanks on
the side and rear, but not from the front. AT-4 is not a guided
weapon.
------------------------------
Date: Monday, 3 November 1986 08:06-EST
From: Jane Hesketh <jane%aiva.edinburgh.ac.uk at Cs.Ucl.AC.UK>
To: ARMS-D
Re: Star Wars flawed #7-of-10
Why SDI's perceptual subsystem will be unsuitable
Introduction
This report summarizes the problems with threat perception
and tracking that will contribute to SDI being unable to
meet its reliability and cost effectiveness requirements.
The problem considered is the detection, recognition and
estimation of motion parameters for 1000 fixed, land-based
missiles. The three key topics discussed are:
o+ the performance of sensors in a difficult and hostile
environment,
o+ the effectiveness of algorithms for object detection,
identification and tracking and
o+ the engineering requirements for constructing the
perceptual subsystem.
Sensors
Problems with event detection and tracking start at the
sensors. The most likely sensors lie in three classes.
They are the direct passive sensors, like optical and
thermal imagers, the direct active sensors, like radar, and
the indirect active sensors, like over-the-horizon or
synthetic aperture radar.
All three sensor classes are vulnerable to three main
types of data degradation: overload, interference and
noise. Overload occurs when a significantly "brighter" than
expected source appears and causes sensor destruction or
target masking. Interference arises from deliberate or
coincident electromagnetic radiation and causes target
masking, non-existent targets and mis-located targets.
Noise is omnipresent and unavoidable and also causes these
three effects. Different sensors are not equally sensitive
to these problems, but all are affected to some extent. The
high amplification needed for operation over long distances
is likely to increase the difficulties. Advancing
technology may reduce the impact of the problems, but cannot
eliminate them. Therefore, all sensors will be vulnerable
to effects that lead to functional failures.
Given the deployment scenario, it is certain that there
will be many causes of data degradation, including:
o+ a dense background star field (for look-up sensors)
with occasional moving objects (such as meteors and
satellites), which need to be examined and ignored
(containing perhaps one million objects depending on
sensitivity and area examined per sensor),
o+ rich background terrestrial texture and clouds (for
look-down sensors),
o+ solar disturbances,
o+ solar and lunar brightness,
o+ likely electromagnetic disturbances (such as nuclear
detonation pulses, terrestrial magnetic field
distortions and solar flares), and
o+ explosions caused by target destruction.
These are largely-natural phenomena that cause existing
sensors considerable problems. Active counter-measures can
also be easily designed to overload, confuse or interfere
with most sensors. Therefore, there are many uncontrollable
natural and man-made sources of data degradation.
The failures resulting from this sensory data degradation
are:
o+ type 1: masking or loss of targets,
o+ type 2: generation of false (non-existent) targets, and
o+ type 3: erroneous estimation of the spatial or temporal
position of the target.
Given the requirements of the SDI task, all three result in
catastrophic failures, the first and third from nuclear
destruction in wartime and the second from triggering
warlike activity and hence mutual destruction in peacetime.
A well-known result from detection theory shows that the
probability of the type 1 failure can be effectively
minimized to zero only at the expense of significantly
increasing the likelihood of the second failure. The type 2
failure implies a massive increase in cost to deploy against
all spurious as well as real targets (including decoys). It
would be reasonable to provide for detecting ten times as
many false targets as the real target quantity (1000
objects). A more serious problem is falsely initiating a
attack-launched condition. Given that the probability of
this failure must be traded off against the type one
failure, we can conclude that a false alarm must eventually
occur. The type 3 failure, mis-location, can be corrected
for when arising from random errors by averaging, provided
enough time exists and object motion is well-behaved, both
of which are unlikely in the battlefield scenario.
Systematic errors must be presumed deliberate (for example,
stealth technology or active counter-measures) and hence are
largely unpredictable. Diagnosis and correction (presuming
knowledge of the possible obstructions) requires other
equally vulnerable sensing and interpretation processes.
Hence, the likely types of sensor failures will make SDI
grow multiplicatively as the number of targets and still not
be 100% reliable.
Many of these phenomena occur even in carefully
controlled laboratory settings, so an uncontrollable and
unpredictable battle environment is likely to cause
significantly more failures.
Data interpretation
The four interpretation problems are launch detection,
object location, object identification and object tracking.
Launch detection obviously requires 100% safety, but
this cannot occur because of sensor limitations. Existing
strategic alert systems are famous for their failures and
new systems will require decisions ten times faster, as well
as being largely automated. Repeated analysis over the
allowed minute or two will reduce, but cannot eliminate the
possibility of false alarms and missed events, either of
which is likely to initiate cycles of automatic activity
leading to nuclear destruction.
Object location depends on isolating a target from
uninteresting background and accurate calculation of object
positions. The first problem can probably only be
practically solved using object motion. Doppler sensing
requires using highly vulnerable radar sensors. Discrete
difference detection requires massive computation per sensor
plus some delay between images and is known to be
unreliable. Continuous difference, or streak detection from
a (slightly) moving sensor also requires massive
computation, hardware not yet well developed and new
interpretation techniques. In all cases, the computed
results are often marginal and subject to misinterpretation,
even by humans.
Position estimation requires complete data from a single
sensor or integrating data from multiple sensors. Single
sensor solutions, like radar, provide unique estimates and
may have the desired accuracy, but are vulnerable to
interference.
Multiple sensor solutions require pairing partial
information from separate sensors, which is known to be hard
even in more restricted domains. Existing stereo algorithms
have easier constraints, yet still produce erroneous
results. Multiple nearby launches from integrated sites,
nearby MIRV vehicles or decoys virtually guarantee erroneous
pairings resulting in mis-located targets. Therefore, it is
highly likely that some targets will not be detected and
others will be mis-located. Multiple sensor systems also
require high-speed, secure and 100% reliable communication
links, otherwise information from groups of sensors cannot
be integrated.
With sufficient counter-measures, object identification
is unnecessary. Cost-effectiveness arguments, however, make
it likely that some form of identification is necessary to
discriminate between real targets, decoys and launch
clutter. Destroying a missile will radically increase the
number of debris objects following the same trajectory and
will thus require greater resources to eliminate these from
consideration.
Pattern recognition methods are notoriously unreliable
for identification unless the target features are
unambiguous and highly discriminating. The features likely
to be used here probably will not meet these criteria.
Model-based artificial intelligence methods are advanced
enough to discriminate only if the target shapes are
significantly different and a large enough high-quality
image can be obtained. Debris is unlikely to look like a
target, but decoys certainly will. Another unsolved problem
is how to recognize a motion-blurred object. Radar
identification techniques depend on highly impoverished and
ambiguous data, so their abilities are limited, particularly
at long distances and with similar objects. In any case, we
may assume unanticipated decoys, camouflage and stealth
technology will be applied, reducing the odds of correct
identifications. Hence, visual theory and engineering are
not sufficiently advanced yet to guarantee object
identification. However, some of the scientific principles
behind reliable object identification in this scenario might
possibly be developed over the funding period, with
considerable expense and several fortuitous breakthroughs.
Object tracking from platforms with known motion is more
advanced. Multiple objects with slightly varying
trajectories periodically observed can be tracked and their
motion parameters estimated. One major difficulty is
initiating the tracking through determining which early
object observations are related. While objects will have
largely vertical motion at launch, it is also certain that
there will be many real and decoy targets moving in similar
trajectories launched from nearby locations. This greatly
increases the chances of mis-pairing observations, and hence
mis-estimating trajectories. A second unsolved problem is
tracking objects that manoeuvre maliciously to defeat
detection or interception. Hence, tracking may be feasible,
but there are several difficult and unsolved problems whose
potential solutions cannot be fully tested before operation.
Engineering
This section raises several engineering problems on top of
the scientific problems raised above.
To reliably detect and track an estimated 1000 true
targets, something like 10,000 sensor systems will be
needed, assuming all are appropriately located, operate
effectively and are not `jammed'. High quality data will be
needed, producing an estimated 100 million pixels (or pieces
of data) per second (TV produces about 10 million). Several
researchers have estimated satisfactory image analysis
requires about 10,000 computer operations per pixel
(although 100,000 is closer to my experience). Hence, the
computational requirements are conservatively 10 to the
power of 16 operations per second. This is totally beyond
the capability of the entire world's computer processing.
Assuming new technologies and specialized processors provide
one thousand million operations per second, this still
implies 10 million as yet undeveloped and undoubtedly
expensive processors will be needed (and possibly 100 times
as many).
This cost of such processing power is likely to be from
100 thousand million pounds to 1 million million pounds.
Given limited military budgets, no complete solution is
affordable.
There is no scientific or engineering experience in
utilizing and controlling much more than 100 independent
processor groups, let alone the 10,000 (minimum) required
here. Knowledge is also lacking in how to detect failure
and dynamically re-allocate resources as units are
destroyed. This self-monitoring and reporting must proceed
in peace-time, which will disclose much intelligence
information and make the system more vulnerable to counter-
measures.
Additionally, because the activity is distributed and
several spatially separated observations are needed to
ensure reliable position location, it will be necessary to
have a secure, jamproof, reliable and high bandwidth
communication pathway. Given likely electromagnetic and
counter-measure disturbances, as well as physical
destruction of units, the satisfaction of these
communication requirements seems unlikely.
Given that each sensor group is largely autonomous, and
will do only a single analysis, it will be difficult, if not
impossible to ensure that all targets are being tracked.
Finally, the 10,000 sensor groups will probably need to
be based in at least 100 highly stable geosynchronous orbits
over the launching areas. This seems politically unlikely.
Even assuming SDI were scientifically feasible,
engineering analysis shows that even the perceptual analysis
subsystem of SDI will be one thousand times larger, more
complicated and more expensive than any perceptual system
created to date.
Conclusions
The main conclusions from above are:
o+ The data received by the sensors will never be perfect,
all sensor types are vulnerable to this, and thus must
occasionally produce erroneous results.
o+ Current visual theory cannot guarantee 100% reliable
detection, identification or motion parameter
estimation.
o+ Engineering expertise is insufficient to construct a
perceptual system likely to be 1000 times more complex
than previously constructed.
This analysis was carried out only for 1000 fixed land-based
missiles. This is the easiest and most vulnerable of the
strategic missile delivery systems. There are also mobile
land and submarine-based missiles or air and sea launched
cruise missiles. Since each of these can be launched from
largely unpredictable locations and may follow more
difficult-to-track flight paths, the resource requirements
are likely to be at least 10 times greater, and the
technical problems considerably more difficult. World-wide
observation also implies any airborne object will be a
potential target, ensuring false alarms and possible
destruction of civilian vehicles. The conclusion is that
the other missile basing methods will decrease the
certainity of interception and will increase the peace-time
risk to civilians.
Hence, SDI will be a neither technically perfect, nor cost-
effective complete shield against massive nuclear attack. It
will also be an imperfect implementation of a partial
defence of military targets.
------------------------------
Subject: Re: Meteorite as A-explosion
Reply-To: unisoft!jef@ucbvax.Berkeley.EDU
Date: Mon, 10 Nov 86 13:55:45 PST
From: Jef Poskanzer <unisoft!charming!jef@ucbvax.Berkeley.EDU>
In Arms-D V7 #53, Steve Walton writes:
>There is only a small chance that a meteorite would hit in the middle
>of a major city; it is much more likely to land in the ocean. No
>radiation, of course, which I think is why Larry asks about anti-matter
>meteorites.
But if a plain old normal matter meteorite did happen to land in a city,
it would be indistinguishable from a nuke until hours or days later, when
reliable reports on the lack of fallout came in. And even a normal matter
meteorite, if it was large enough, would give off some prompt ionizing
radiation. X-rays from the plasma. That wouldn't result in any fallout,
but it might trigger X-ray-detecting satellites such as the Vela series.
That could cause some fingers to stray towards some buttons.
>Besides, the conversion of 1 gram of anti-matter (a cube less than
>1 cm on a side) to energy would produce 9 x 10^20 ergs of energy,
>which is probably enough to split the earth in two.
If you want to get into science fiction, at least get the physics
right. A gram of antimatter would produce 18 x 10^20 ergs, because
an equal mass of normal matter would also be converted to energy.
18e20 ergs is about 40 kilotons, hardly enough to split the earth
in two. For that, you would need about 2.25e39 ergs.
>Such a particle would also produce a long trail of annhilations on
>its way in to the Solar System, due to collisions with the atoms in
>the solar wind, the density of which is about 10 atoms per cubic
>centimeter near the earth and more than 1 per cc even at Jupiter.
>The resulting trail would be easily visible.
I doubt it.
Jef Poskanzer, UniSoft Systems, Berkeley
unisoft!jef@ucbvax.Berkeley.EDU
...ucbvax!unisoft!jef
(415)644-1230
------------------------------
Subject: Re: Unequivocal confirmation of detonation
Date: Mon, 10 Nov 86 15:27:48 -0800
From: Tim Shimeall <tim@ICSD.UCI.EDU>
>From: LIN@XX.LCS.MIT.EDU
> From: "NGSTL1::SHERZER%ti-eg.csnet" at RELAY.CS.NET>
> You misunderstand what I said. The tankers cannot keep THEMSELVES (not
> to mention the bombers) in the air for 24 hours. This means that NONE
> of the bomber force would survive.
>But they could. There is no intrinsic reason that a tanker cannot
>itself be refueled in the air.
Oh come on! That leaves us with:
Tankers to fuel tankers (good until T+12h)
Tankers (good until T+24)
Bombers (good until T+36 or so)
All of which must use the same launching facilities for the brief
period (10 minutes? 15?) between the detection of the attack and the
destruction of the facility.
It seems to me that this is impractical, to say the least. Also,
how quickly can we fuel these tankers? As I recall, aircraft fuel
tanks are subject to condensation, which makes problems.
Tim
------------------------------
Date: Monday, 10 November 1986 18:05-EST
From: cfccs at HAWAII-EMH
To: ARMS-D
Re: SDI
I guess the blast for Hawaii was aimed at me. I'm sorry that I've
given you the idea that I don't pay attention. Let me assure you that
I do. The difference is that I don't believe everything that comes in
print as Gospel.
I do know that nearly everyone agrees that we will not be ready for
any demonstrations (using gigabucks?) for at least 5 years, maybe
more. So in 5 years, lets all get together again and argue about
something real rather than hypothetica
The arguements against SDI seem to want the funding cut. They want a
nice slow progress that will assure no quantum jumps in technology.
One that will leave plenty of money for the projects they can't seem
to get funds for. Not that cuttig SDI finding would do that, but it's
a good place to let out frustratthe frustrations. If you aren't
against SDI R&D (notice the D stands for developme), what are you
arguing about? If your real concern is that money will be wasted on
elaborate shows of outdated technology, then argue that!
At least then you would have a case!
CFCCS @ HAWAII-EMH
------------------------------
Date: Mon, 10 Nov 86 18:02 EDT
From: "Paul F. Dietz" <DIETZ%slb-test.csnet@RELAY.CS.NET>
Subject: New Isotope Enrichment Technique Discovered
A new techniquw for isotope separation has been developed by Gerald R.
Stevenson and colleagues at Illinois State U. The technique depends
on differences in electron affinity of molecules containing different
isotopes. (Nature, Oct. 9)
In their experiment, the researchers dissolved nitrobenzene in liquid
ammonia. Metallic potassium was added, forming potassium ions and
free electrons. The electrons preferentially bound to nitrobenzene
molecules containing nitrogen-15. The nitrobenzene anions could
then be separated chemically and converted back to neutral molecules.
The process can enrich nitrogen-15 from 0.37% to 99% in 16 passes.
Similar effects were found with molecules in which deuterium replaces
hydrogen-1 and in molecules in which heavy isotopes of carbon occur.
Stevenson says that to separate the isotopes of an element an organic
molecule containing that element must be found that will accept an
electron, but the rest is relatively straightforward.
The implications for proliferation are serious. A cheap process
for making heavy water will make it easier to manufacture
plutonium from unenriched uranium. Uranium enrichment might
become less expensive. The technique might apply to plutonium,
making it possible to separate out nearly pure Pu-239 from
commercial reactor waste.
------------------------------
Date: Mon, 10 Nov 86 18:43:42 PST
From: Clifford Johnson <GA.CJJ@forsythe.stanford.edu>
Subject: Launch on warning / nuclear victory metrics
> From: dm@bfly-vax.bbn.com
> The Russians have announced that, in the face of deployment of
> SDI, they'll have to go to a launch-on-warning policy.
Where can I find this annoucment? (N.B. Since the U.S. called
their bluff on the same threat re Pershings, it doesn't count for
much -- LOW is suicidal, and, as argued below, I think it always
unconscionable, besides being perfectly well avoidable.)
LIN> The whole point is deterrence, which if it holds saves the day.
LIN> If it fails, the day is lost, by whatever metric of "victory"
LIN> you choose.
I agree with your sense entirely, but...
The department of defense is implementing metrics that define
"victory" after a nuclear exchange, for example in terms of the
difference in number of remaining warheads after the exchange.
That's also how their war games like Big Stick work.
While we debate what our nuclear forces could do after riding out an
initial salvo, the DOD has real-time models that maintain reports,
for example, on the "Price of Going Second," which represents the
"price, measured as a percentage change in the ratio of
intercontinental weapons, of going second in a nuclear exchange
rather than first... It should be evaluated by a subroutine taking
into account the nature of the missile arsenals, accuracies,
reliabilities, and vulnerabilities." If this price exceeds a
threshhold, then a higher-alert LOW could be triggered; and if
there were also a strategic warning, it could trigger a preemption
recommendation. The quote is from an RSAC -- Rand Strategy
Assessment Center -- description. I'm told RSAC is "coming online"
within the DOD by year-end. Anyone know any details about the
implementation?
LIN> I do believe that the U.S. should maintain an LOW option, for
LIN> the reason that it is a hedge against breakthroughs in ASW.
Even without a single sub, I think LOW unconscionable on more than
one ground. We agree that in a high-alert operation, LOW is very
dangerous, and you agree that once we have the kind of sized launch
implied by a LOW, there's no victory. would add that a one-sided
accidental LOW could per se cause nuclear winter.) So, you would
risk everything for fear we'd get nuked out? I don't see how any
circumstances whatsoever could justify the creation, by us, of the
possibility that due to our fault humanity could be extinguished by
mistake. Besides, we don't just have subs. as backup, there's nukes
all over the world now. The point is, pragmatism is pulling us over
the brink of doom, and it would be strengthening to rise above all
dependence on LOW.
To: ARMS-D@XX.LCS.MIT.EDU
------------------------------
Date: Mon, 10 Nov 1986 22:26 EST
From: LIN@XX.LCS.MIT.EDU
Subject: 24 hour endurance for bombers
> From: "NGSTL1::SHERZER%ti-eg.csnet" at RELAY.CS.NET>
> You misunderstand what I said. The tankers cannot keep THEMSELVES (not
> to mention the bombers) in the air for 24 hours. This means that NONE
> of the bomber force would survive.
>From: LIN@XX.LCS.MIT.EDU
>But they could. There is no intrinsic reason that a tanker cannot
>itself be refueled in the air.
From: Tim Shimeall <tim at ICSD.UCI.EDU>
Oh come on! That leaves us with:
Tankers to fuel tankers (good until T+12h)
Tankers (good until T+24)
Bombers (good until T+36 or so)
All of which must use the same launching facilities for the brief
period (10 minutes? 15?) between the detection of the attack and the
destruction of the facility.
It seems to me that this is impractical, to say the least.
Are you saying that if we wished to spend the money, we could not
maintain an airborne alert? If you concede this, then it seems my
suggestion is technically feasible; expensive, perhaps, but feasible.
------------------------------
Date: Mon 10 Nov 86 22:41:46-EST
From: Herb Lin <LIN@XX.LCS.MIT.EDU>
Subject: Re: Launch on warning / nuclear victory metrics
From: Clifford Johnson <GA.CJJ@forsythe.stanford.edu>
> From: dm@bfly-vax.bbn.com
> The Russians have announced that, in the face of deployment of
> SDI, they'll have to go to a launch-on-warning policy.
Where can I find this annoucment? (N.B. Since the U.S. called
their bluff on the same threat re Pershings, it doesn't count for
much -- LOW is suicidal..
How would you know if they have or have not gone to an LOW policy?
They may exercise that option, but that doesn't mean they have
implemented LOW as a matter of policy.
LIN> I do believe that the U.S. should maintain an LOW option, for
LIN> the reason that it is a hedge against breakthroughs in ASW.
Even without a single sub, I think LOW unconscionable on more than
one ground.... So, you would
risk everything for fear we'd get nuked out? I don't see how any
circumstances whatsoever could justify the creation, by us, of the
possibility that due to our fault humanity could be extinguished by
mistake.
I suppose I would risk everything for fear that we'd get nuked out.
Look, that is the problem with nukes in the first place. If you
believe in deterrence, it means that that you have to be willing to
promise that you will do something irrational *if* deterrence fails
and war breaks out. Without the fear of nuclear war breaking out,
one-sided nuclear attack becomes a more realistic possibility. Given
that I accept deterrence as a sad necessity of the nuclear age, it's
not much farther for me to accept the idea of "risking everything",
since that is what I am doing already.
------------------------------
Date: Sunday, 9 November 1986 11:41-EST
From: hplabs!pyramid!utzoo!henry at ucbvax.Berkeley.EDU
To: arms-d, risks@CSL.SRI.COM
Re: Friend-foe identification (from RISKS)
In the course of catching up on Flight International (the British
analog to Aviation Leak), I ran across an interesting item in the 7
June 1986 issue. The UK Ministry of Defence officially admitted that
a British helicopter, shot down in the Falklands War with all four
aboard killed, was downed by a Sea Dart missile from a British
destroyer. On 6 June 1982, HMS Cardiff reported shooting down an
Argentine helicopter flying in darkness toward Port Stanley. It was
actually a British Army Gazelle on a resupply flight between Darwin
and Mount Pleasant. The lack of Argentine wreckage and the
coincidence of timing were noticed, but a forensic investigation was
unable to establish a firm connection. Forensic tests in the last
year or so have pretty much settled the question. MoD apparently
won't discuss how the misidentification occurred.
(This sort of thing is far more common in combat than most people
think. In WW2 there was a standing joke about how antiaircraft
gunners decided whether an aircraft was friendly or hostile:
approaching = hostile, receding = friendly.)
Henry Spencer @ U of Toronto Zoology
{allegra,ihnp4,decvax,pyramid}!utzoo!henry
------------------------------
End of Arms-Discussion Digest
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