Hello Peter,
not a dumb question at all. While gravity gradiometers require essentially no free air
or Bouguer slab correction, the terrain correction is very important and an accurate
topographic model is required. My PhD thesis (Airborne Gravity Gradiometry, University
of Western Australia, 1994) briefly mentions the topic giving rough estimates of the
requirement. A paper by Chen and Macnae (Explor. Geophys., 1997, p21-25) looks at a
particular example and there are older references in Geophys. (eg Chinnery, 196? and
Hammer 19??).
I can tell you that the BHP system deals with this problem very well!
cheers
Mark
===================================================================
Dr Mark Dransfield ph. +61-3 9609 4478
BHP Minerals Technology fax +61-3 9609 4489
Discovery Technologies
Level 17, 114 William Street, Melbourne
GPO Box 86A, Melbourne, VIC, 3001
AUSTRALIA [EMAIL PROTECTED]
===================================================================
-----Original Message-----
From: Peter Walker [mailto:[EMAIL PROTECTED]]
Sent: Friday, 19 May 2000 23:28
To: [EMAIL PROTECTED]
Subject: Re: [SEGMIN]: BHP's Airborne Gravity Gradiometer System
Hi Ken
Perhaps this is a dumb question, but since a gradiomenter
is essentially a shallow penetrating instrument (compared
with the field), and since the largest effect has to be the
contrast at the air-earth interface, won't the gradiomenter
be inordinately sensitive to topography? Ie: to tease geologic
signal from the data, will it not be necessary to have a very
accurate topographic model?
Peter
----- Original Message -----
From: "Ken Witherly" <[EMAIL PROTECTED]>
To: "Segmin@Lists. Geosoft. Com" <[EMAIL PROTECTED]>
Sent: Thursday, May 18, 2000 7:37 PM
Subject: [SEGMIN]: BHP's Airborne Gravity Gradiometer System
> BHP announced yesterday that their airborne gravity gradiometer system is
> flying. The attached JPEG is from a local (Melbourne) newspaper. The url
> leads to the full talk (lots of other BHP bumf), there are some additional
> images showing data from Ekati and Western Australia. Enjoy.
>
> Ken Witherly
>
> http://www.bhp.com.au/financials/brief/default.htm
>
>
> Condor Consulting, Inc.
> St. 206, 4860 Robb Street
> Wheat Ridge CO 80033
> Tel: 303-423-8475
> Fax: 303-423-9729
> www.condorconsult.com
>
>
>
> _______________________________________________________
> List archive: http://www.mail-archive.com/[email protected]
>
>
>
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