(19)

(11)

EP 3 894 780 A1

(12)

(43) Date of publication: 20.10.2021 Bulletin 2021/42 (21) Application number: 19816381.8 (22) Date of filing: 25.11.2019

(51) International Patent Classification (IPC):  F42B 35/00(2006.01) G01L 5/14(2006.01) (52) Cooperative Patent Classification (CPC): F42B 35/00; G01L 5/14 (86) International application number: PCT/GB2019/000161 (87) International publication number: WO 2020/120925 (18.06.2020 Gazette 2020/25)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 11.12.2018 GB 201820139 (71) Applicant: The Secretary of State for Defence Salisbury, Wiltshire SP4 0JQ (GB)	(72) Inventor: COOKE, Samuel Brendan Dixon Salisbury, Wiltshire SP4 0JQ (GB) (74) Representative: Farnsworth, Alastair Graham  DIPR Formalities Section Poplar 2nr. 2214 MOD Abbey Wood (South) Bristol BS34 8JH Bristol BS34 8JH (GB)