The Horizon arrangement divided responsibilities between a Paris-based Principal Anti-Air Missile System office and a London-based ship project office. Britain contributed funding to the missile system and shared construction work with France and Italy, but the partners could not settle on one principal radar. France and Italy chose the passive electronically scanned EMPAR, while Britain selected the active electronically scanned SAMPSON. Both receive a positive assessment, with SAMPSON judged slightly better for extending the protective bubble over a fleet. The later move toward active arrays supports that preference. The compromise retained common missiles alongside different principal radars.
Chapter · 25:52-28:03
PAMS cooperation split over SAMPSON and EMPAR radar fits
Britain joins Horizon and PAMS but chooses the active-array SAMPSON radar while France and Italy retain EMPAR, preserving common missiles without a common sensor fit.