(19)

(11)

EP 0 250 553 A1

(12)

(43) Date of publication: 07.01.1988 Bulletin 1988/01 (21) Application number: 87900509.0 (22) Date of filing: 10.12.1986

(51) International Patent Classification (IPC):  G01S 7/ 40( . ) G01S 7/ 288( . ) (86) International application number: PCT/US1986/002658 (87) International publication number: WO 1987/003967 (02.07.1987 Gazette 1987/14)

(84) Designated Contracting States: BE CH DE FR IT LI NL SE (30) Priority: 17.12.1985 US 19850810034 (71) Applicant: SIGNATRON, INC. Lexington, MA 02173 (US)	(72) Inventor: MAHONEY, Paul, F. Brighton, MA 02135 (US) (74) Representative: SERJEANTS  25 The Crescent King Street Leicester, LE1 6RX Leicester, LE1 6RX (GB)