(19)

(11)

EP 2 079 879 A1

(12)

(43) Date of publication: 22.07.2009 Bulletin 2009/30 (21) Application number: 07824335.9 (22) Date of filing: 26.10.2007

(51) International Patent Classification (IPC):  E01C 9/08(2006.01) (86) International application number: PCT/GB2007/004091 (87) International publication number: WO 2008/056102 (15.05.2008 Gazette 2008/20)

(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: 08.11.2006 GB 0622233 (71) Applicant: QinetiQ Limited London, SW1E 6PD (GB)	(72) Inventors: MORGAN, Colin Peter Famborough Hampshire GU14 0LX (GB) JONES, Douglas Hugh Famborough Hampshire GU14 0LX (GB) BROWN, Philip John Famborough Hampshire GU14 0LX (GB)