SAMPSON  The SAMPSON is a multi-function dual-face active electronically scanned array radar produced by BAE Systems Maritime. It is made out of high-carbon steel and is covered with an anti-radar paint. It is the fire control radar component of the Sea Viper naval air defence system. It was previously designated PAAMS(S) to distinguish it from the PAAMS system on the Franco-Italian Horizon Class. The SAMPSON multi function radar can detect all types of targets out to a distance of 400 km, and is capable of tracking hundreds of targets at any one time. Sea Viper uses this information to assess and command target priorities, and calculate the optimum launch time for its Aster missiles. SAMPSON is derived from the Multi-function Electronically Scanned Adaptive Radar (MESAR) programme. MESAR 1 development commenced in 1982 as a partnership between Plessey, Roke Manor Research and the Defence Evaluation and Research Agency. Plessey was acquired by Siemens in 1989 to become Siemens-Plessey, itself acquired by British Aerospace in 1998. British Aerospace became BAE Systems in November 1999. MESAR 1 trials occurred between 1989 and 1994. MESAR 2 development began in August 1995, of which SAMPSON is a derivative. The Royal Navy intended to deploy the SAMPSON MFR on its version of the Horizon CNGF - a collaboration with France and Italy to produce anti-air warfare frigates. Following delays and complications the UK withdrew and started its own Type 45 programme. The Type 45 destroyers use the SAMPSON radar with the PAAMS missile system, which was also developed for the Horizon frigates (French and Italian ships are to be fitted with the EMPAR MFR). The SAMPSON Radar is made in Cowes, Isle of Wight. Conventional radars, consisting of a rotating transmitter and sensor, have limited power, are vulnerable to enemy jamming and perform only one function - with separate units therefore required for surveillance, tracking and targeting. As an active array, SAMPSON uses software to shape and direct its beam allowing several functions to be carried out at once and, through adaptive waveform control, is virtually immune to enemy jamming. Active arrays have both longer range and higher accuracy than conventional radars. The beam-directing software uses sophisticated algorithms to schedule looks so that the potentially hundreds of active tracks are maintained with maximum accuracy. The SAMPSON uses two planar arrays to provide coverage over only part of the sky; complete coverage is provided by rotating the arrays, essentially similar to the way conventional radar systems operate.