(19)

(11)

EP 2 016 442 A1

(12)

(43) Date of publication: 21.01.2009 Bulletin 2009/04 (21) Application number: 07732525.6 (22) Date of filing: 24.04.2007

(51) International Patent Classification (IPC):  G01S 13/87(2006.01) G01S 13/42(2006.01) (86) International application number: PCT/GB2007/001486 (87) International publication number: WO 2007/122408 (01.11.2007 Gazette 2007/44)

(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 Designated Extension States: AL BA HR MK RS (30) Priority: 25.04.2006 GB 0608165 (71) Applicant: PI Research Limited Cambridge CB4 6WZ (GB)	(72) Inventor: TREHERNE, Ian Michael Oxford OX3 8JS (GB) (74) Representative: Goodman, Simon John Nye  Reddie & Grose 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)