Engineering services

Underwater electromagnetic signature modelling

Ultra Electronics, EMS has over 10 years experience and validation of the Finite Element Modelling and Analysis Package (FEMAP) software suite with ranged ships and submarines. The modelling techniques and optimisation algorithms assure accuracy, efficiency, speed and confidence in assessing a ship or submarine's underwater electromagnetic signature.

FEMAP software and modelling services can also be used to assess the ship and submarine on-board equipment contribution to underwater electromagnetic (UWEM) signature and evaluate design changes for minimization of signature from the equipment.

UWEM fields emitted by a ship or submarine:

  • Permanent static magnetic fields
  • Induced static magnetic fields
  • Alternating magnetic fields
  • Static electric fields
  • Corrosion related magnetic fields
  • Alternating electric fields
  • Alternating CRM fields
  • Stray electromagnetic fields

Factors contributing to underwater electromagnetic signature:

  • Construction material of the ship, equipment installed on the ship, mission modules
  • Location and placement of equipment on the ship
  • Pitch and roll of the ship during operating conditions and missions
  • The corrosion rate of the ship structure, tanks, propellers, waterjets, bow thrusters, sonar domes and other immersed systems
  • Rotating shaft systems for the propellers, waterjets and bow thrusters
  • Electrical power and signal system wiring for the ship, ship equipment and mission modules
  • On-board electromagnetic radiation of electronic systems

FEMAP software

EMS is able to model total UWEM signature and design a complete suite of countermeasure systems via computational methods, using a combination of commercially available software modules (FEM, BEM and graphing/computation) and an in-house optimization and ship/sub specific suite of software called FEMAP.

FEMAP software and modeling techniques have been validated in both the USA and UK against both signatures of physical scale models of vessels and actual ship signatures. EMS has successfully designed, delivered and calibrated several USN, NATO and allied nation ship classes using FEMAP.