(19)

(11)

EP 0 438 562 A1

(12)

(43) Date of publication: 31.07.1991 Bulletin 1991/31 (21) Application number: 90911960.0 (22) Date of filing: 15.08.1990

(51) International Patent Classification (IPC):  G01S 15/ 89( . ) G10K 11/ 34( . ) (86) International application number: PCT/GB1990/001291 (87) International publication number: WO 1991/002989 (07.03.1991 Gazette 1991/06)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 15.08.1989 GB 19890018577 (71) Applicant: SEA SCAN TECHNOLOGY LTD: Gwent NP2 4EF (GB)	(72) Inventor: PHILLIPS, Peter, Stanley Abergavenny Gwent (GB) (74) Representative: Gibson, Stewart Harry, et al  URQUHART-DYKES & LORD, Three Trinity Court, 21-27 Newport Road Cardiff CF2 1AA Cardiff CF2 1AA (GB)