SAMPSON

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.[2][3] 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.[2] MESAR 2 development began in August 1995, of which SAMPSON is a derivative.[4]

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.

The mainmast of HMS Daring showing the SAMPSON multi-function AESA radar

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.[5]

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. This is in contrast to the US AN/SPY-1 system (as used on the Ticonderoga class cruiser and Arleigh Burke class destroyer) or the Dutch APAR system (as used on the Royal Netherlands Navy's De Zeven Provinciën class frigates, the German Navy's Sachsen class frigates, and the Royal Danish Navy's Ivar Huitfeldt class frigates), which use multiple arrays fixed in place to provide continuous coverage of the entire sky.

Whilst this may seem to be a disadvantage, the SAMPSON radar rotates at 30 revolutions per minute, with two back-to-back arrays, meaning no part of the sky lacks coverage for more than one half second on average - the precise time varies as the beams can also be swept back and forth electronically. In addition, the use of a smaller number of arrays allows the system to be much lighter, allowing placement of the arrays at the top of a prominent mast rather than on the side of the superstructure as in the Dutch or US ships. Placing any radar emitter at higher altitude extends the horizon distance, improving performance against low level or sea-skimming targets; SAMPSON is at approximately double the height above the waterline than the arrays of its Dutch or US equivalents. Although precise details of the SAMPSON's performance in this regard are unlikely to enter the public domain, such factors may mitigate the disadvantages of fewer arrays.

Some tasks are difficult to combine, for example (long range) volume search takes a lot of radar resources, leaving little room for other tasks such as targeting. Combining volume search with other tasks also results either in slow search rates or in low overall quality per task. Driving parameters in radar performance is time-on-target or observation time per beam. This is why the Royal Navy selected the S1850M Long Range Radar to complement Sampson on the Type 45 destroyers. It is also a reason why the NATO Anti-Air Warfare System study (NAAWS) defined the preferred AAW system as consisting of a complementary Volume Search Radar and MFR. This gives the added advantage that the two systems can use two different radar frequencies; one being a good choice for long range search, the other a good choice for an MFR (as physics makes both tasks difficult to combine).[3]

The first Type 45, HMS Daring was launched on February 1, 2006. The ship was fitted with SAMPSON and S1850M radars in 2007. She underwent trials before being commissioned 23 July 2009.

• Phased array
• Active electronically scanned array
• Active phased array radar
• AN/SPY-3
• AN/SPY-6
• EL/M-2248 MF-STAR
• OPS-24
• OPS-50
• Selex RAT-31DL
• Selex RAN-40L
• Type 346 Radar

• BAE Sampson Radar