From: iw@all.net
Subject: IW Mailing List iw/960126
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Date: Thu, 25 Jan 1996 19:08:49 -0700 (MST)
From: Istvan 
Subject: Re: Info Corps

Dan Meyer, general counsel, The Strategy Group 
 writes:

> Some empirical observations about the current debate over 'info corps'
> and 'info warfare' in general.  First, let's understand that the 'net'
> is only the latest in a series of 'carriage' media: rude tracks, plank
> roads, toll roads, canals and railroads, and aeroplanes--ignore these as
> mere transportation.  "Carriage" means just that; and all carried
> information. 

I'll beg to differ with Dan's final statement here.  Those systems did not
carry information as such ... at least not within the paradigm of
Information Theory that I'm used to dealing with.  They carried "data". 

Data hopefully is separated from Information within these list
discussions. Otherwise we will be prone to grievous misunderstandings as
to both the capabilities and requirements, when we're discussing IW.  (I'm
not sure if "information" ever was defined on the list??)

[Moderator's Note: Two definitions of information were provided (I
think).  Certainty, or more precisely the elimination of uncertainty,
ala Shannon's syntactic information theory circa 1948 is the one more
commonly used.  The other was "symbolic representations in the most
general sense", which is related to Bar-Hillel and Carnap's paper on
semantic definitions of information (in the early 1950s I think).]

... 
Take as an example, the CNN feed of President Clinton boarding his plane a
week or two ago to go to Bosnia.  Data or information?  Many would
consider the CNN feed to be information, when in point of fact it was
simply data.  To anyone who was even moderately observant, and looked at
the footage as a data stream, it was clear that the footage was false.
(The President has a gait which is alternate to that of the man who was
shown climbing the stairs to Air Force One.)

[Moderator's Note: This seems to be a claim the Clinton did not go and
that the whole thing was just a disinformation campaign.  Was anyone on
the list in Bosnia so we can definitively refute this?]

...
Information is ultimately what is derived from all of the data streams
which feed into available processing capabilities.  The "carriage" that
Dan refers to is what carries "data".  It does not, and will not _ever_
carry information, because information is ultimately something which is
_derived_ from a data flow. 

[Moderator's Note: Sounds like Shannon's theory - there are a-priori
probabilities and a-posteriori probabilities derived from a-priori
probabilities mixed with new signals.  The difference in probabilities
is the information content of the signals.]

...
To glean any useful information, you'd have to know other data pieces. 
...
Without knowing answers to these questions, you're pretty much flying in
the dark with your data. 

...
For an improvement, someone truly needs a relevant information flow.  It
almost necessitates, that one has to enter the theatre in some form. 
Otherwise, one simply runs the risk of "information overload" -- which is
more accurately described as a "data" overload, rather than an information
overload. 

> Point is, once the net is up, its security has two components: one for
> the warriors, and the other for the lawyers.  Warriors maintain, in a
> passive sense, system borders.  Law, and it's insurance/investment
> surrogates, insure internal integrity.  Those seeking extra rich rewards
> invest over the net; and invest in bringing new assets into the web. 
> Ensuring the internal integrity means just that; you allow for just
> enough insecurity to match risk and reward, and then you insure the
> remainder. 

...
And the risk/reward equation in this new information space, that Dan
references is such that the potential risks and liabilities are infinite
and catastrophic.  Not even Lloyd's will insure that form of risk.  They 
specifically exclude war zones.

> Which means, in a very real sense, the warriors will hinder the rewards
> of the new carriage system if they roam the internal security system. 

The answer then is a "police" oversight, and then a "warrior" oversight. 
Each should function in parallel and should complement the other.  Not 
only co-operatively, but competitively.

Checks and balances provide the rhythm which creates a long term system 
of stability.  It's like a pendulum.  Nothing really new.
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Date: Fri, 26 Jan 1996 17:17:43 -0500
From: cobbjw@ornl.gov (John W. Cobb)
Subject: Re: IW Mailing List iw/960125 - satellite imaging resolution

>[Moderator's Note: This seems highly unlikely.  What is the theoretical
>basis for believing that you cannot get resolution down to twice the
>wavelength of the light being measured? There is also no reason to limit
>ourselves to visible light.]

The theoretical basis is called diffraction limited optics.  The
resolution depends not only on the wavelength of light, but on the
distance and the size of the collector (space antenna).  Smaller
wavelength or larger collectors or shorter distances all lead to higher
resolution.  The theoretical diffraction limit is almost always the
limiting factor for satelite observations (at least to my knowledge)
except for obscuring cloud problems. 

Another limit is turbulent atmospheric motion.  This is what causes
stars to twinkle.  Well from a satellites view, it also causes
streetlights to twinkle and dance about a bit.  This is the reason that
the Hubble ST gets such good resolution.  For telescopes the collectors
(main mirrors) are huge so the limit is actually twinkle and not
diffraction. 

Now both of these problems can be skirted with some very ingenious
techniques. 

For turbulence, one can use phase conjugation.  Here a laser is sent
through the atmosphere and reflected back.  Then an interfereometer is
used to measure the relative phase lag and this essentially maps the
current turbulence.  The light is fast enough to map out the turbulence
and adjust the mirrors before the character of the turbulence changes. 
So active control can be used to compensate for twinkle --- a realy neat
idea huh? In fact some land-based phase conjugation telescopes have been
used to obtain some amazing pictures, almost rivalling Hubble. 

For diffraction limitation, synthetic apertures can be used.  The idea
here is that the collector may only be of a given size, but it is moving
through space.  Therefore it samples a much larger region than just the
collector area.  However, it is not in all of the positions at once, so
precise timing must be used in order that many snapshots taken at short
intervals can have their data integrated consistently.  In this way the
"effective" collector area becomes larger and hence the resolution
smaller.  The trick is that one must have an excellent timer.  I don't
think one exists currently for light frequencies, but lower frequency
radio-waves can use this technique to great advantage.  Ever hear about
SAR - synthetic aperture RADAR?
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To: cobbjw@ornl.gov (John W. Cobb)
Date: Fri, 26 Jan 1996 17:35:31 -0500 (EST)

> Re: satellite imaging resolution
...

Excellent contribution - but what is the bootom line?
	Can we see golf balls?
	Can we see hair follicles?

Perhaps some theoretical limits would be useful for the crowd to get a
sense of where theory limits us:

Consider	- a very clear night over the desert
		- looking into LA during an inversion

Also, how about time lapse - by taking and correlating multiple images,
don't we get far better resolution? Can GPS and an atomic clock be used
to get very good time and location references?
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