Xref: utzoo sci.space:4380 sci.crypt:775
Path: utzoo!linus!gatech!bbn!lawrence
From: lawrence@bbn.COM (Gabriel Lawrence)
Newsgroups: sci.space,sci.crypt
Subject: Re: satellites
Keywords: Diffraction Limit, Interferometry
Message-ID: <6309@ccv.bbn.COM>
Date: 25 Jan 88 23:31:50 GMT
References: <873@uop.edu> <2166@umd5.umd.edu> <4910@well.UUCP> <1952@netsys.UUCP> <7169@apple.UUCP> <1705@faline.bellcore.com> <1179@basser.oz>
Reply-To: lawrence@ccv.bbn.com (Gabriel Lawrence)
Organization: Bolt, Baranek and Newman Inc., Cambridge MA
Lines: 20


Knowing precious little about optical diffraction limits or advanced uses
of interferometry, you can take what I have to say as having little technical
merit.  I do know that according to a Natl. Public Radio report I heard
last month, Congress has just 'officially' lifted the ban on the 10 meter
satellite optical imaging restriction due to American industrial lobbyists
complaining about unfair international competition.  It has been widely known
that satellites giving much greater resolution have been available outside
of the U.S. for quite awhile.  I believe the new commercial standard is
somewhere in the 3 meter range.  To the best of my recollection, the 
commentator mentioned that while the 10 meter range was sufficient to  
view the individual cars located in the parking lot of the Pentagon, the new
range allowed you to see the contents of the cars through the windows.
This would seem to me to easily make the case for a _commercial_ satellite
being able to spot an individual held hostage if the location of the 
prison/barracks and his physical characteristics was a known quantity.  The
same commentator also acknowledged that military spy satellites were, in all
likelihood, quite a bit more powerful/accurate/higher in resolution than the
best commercial satellites so I'll let you informed usenetter's draw your
own conclusions...