(19)

(11)

EP 2 076 841 A2

(12)

(88) Date of publication A3: 25.09.2008 (43) Date of publication: 08.07.2009 Bulletin 2009/28 (21) Application number: 07853676.0 (22) Date of filing: 28.09.2007

(51) International Patent Classification (IPC):  G06F 15/16(2006.01) (86) International application number: PCT/US2007/079892 (87) International publication number: WO 2008/042774 (10.04.2008 Gazette 2008/15)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR (30) Priority: 29.09.2006 US 848122 P 27.09.2007 US 863062 27.09.2007 US 863081 27.09.2007 US 863103 27.09.2007 US 863121 (71) Applicant: ION Geophysical Corporation Houston, TX 77042-2839 (US)	(72) Inventors: ELDER, Alfred, Keith Richmond, TX 77459 (US) EPERJESI, Richard Stafford, TX 77477 (US) (74) Representative: Jeffrey, Philip Michael  Frank B. Dehn & Co. St Bride's House 10 Salisbury Square London EC4Y 8JD London EC4Y 8JD (GB)