At 07:58 PM 4/29/00 -0700, you wrote:
>George,
>   There was a horribly written article about an incredibly interesting
>subject a few years back in Scientific American.  Even though the article did
>not belong in the magazine, you might be interested in reading it.  It was
>about a gravity gradiometer that had been designed to help submarines "see"
>the topography on the ocean floor and avoid collision with sea mounts.  They
>needed a passive method to see the ocean floor so that they would not be
>detected.  Supposedly this thing worked great (too bad all the data they
>collected is classified).  Anyways, the company that made it was allowed to
>contract its use out to some geophysical concerns, such as finding oil and
>natural gas resevoirs.  The company takes a huge amount of money, throws this
>thing in a boat and drives around for a while.  They take the data, reduce
it,
>and then sell portions of it for commercial use.  Nobody is allowed to buy
>one of these instruments, or use one for themselves.  This is the reason it
>did not belong in the magazine: it was really an ad for the company.  The
>exact technology is still classified, so it is like a magical black box.
>
....snip...
>
John,
	Thanks for the interesting information. I have always thought that the
measurment and understanding of gravity gradients was fascinating, I will
try to find the Scientific American article.
George
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