US NAVY Stealth Technology (Geometry and Water Curtain Technology)

The Sea Shadow, Stealthy Ship Testbed Geometry Advantage - -Sea Shadow, sporting 45º angle Face Its purpose is to explore a variety of new technologies for surface ships, including ship control, structures, automation for reduced manning, seakeeping and signature control . ted, Radar Reflecting/Absorbing, Hull

USS Zumwalt (DD-21) - DD(X) Class Stealthy Multimission Destroyer, -----

Partial List of Anti-Ship Cruise Missiles (ASCM) USA AGM-84 Harpoon / Harpoon Block II France Exocet AM39 / SM39 / MM40 / BC40 AS 15 TT India/Russia Brahmos (PJ10) Russia SS-N-27 Klub SS-N-25 Switchblade SS-N-22 Sunburn SS-N-19 Shipwreck China C-701 Germany AS.34 Kormoran 1/2 EU Polyphem Norway Penguin NSM Britain Sea Skua Sweden RBS 15 Mk3 Italy Otomat Mk2 Israel Gabriel III .

The Adaptive Water Curtain Technology (AWCT) is intended to deflect and scatter enemy radar waves thus reducing the ship’s radar cross section (RCS). It consists of highly conductive sea water sprayed in a fashion that effectively creates an angled radar reflective curtain around the ship To reduce the ship’s remaining RCS, the water curtain can be "modulated" such that the returns appear as "Sea Clutter." This could be done by determining the surrounding Sea State--either locally, or from satellite Sea State data, i.e., deriving the Sea Clutter Spectrum; and applying the appropriate coefficients to the modulating process for optimum mimicry This technology can reduce a surface ship's vulerability to Radar cross-section (RCS), Infrared signature (IR), and Visual signature reduction. . -Water Curtain Modulation- Nozzle Control for 'Sea State' Mimicry To reduce the ship’s remaining RCS, the water curtain can be "modulated" such that the returns appear as "Sea Clutter." This is done by determining the surrounding Sea State--either locally, or from satellite Sea State data, i.e., deriving the Sea Clutter Spectrum and applying the appropriate coefficients to the modulating process for optimum mimicry Active Water Curtain Technology AWCT The Adaptive Water Curtain Technology (AWCT) is intended to deflect and scatter enemy radar waves thus reducing the ship’s radar cross section (RCS). It consists of highly conductive sea water sprayed in a fashion that effectively creates an angled radar reflective curtain around the ship. Water, especially sea water, is highly electrically conductive and if the water droplets are compact enough, RADAR waves will be reflected just as if the surface were metal. Also, streams of sea water will absorb as well scatter radar energy. The system is adaptive, that is, it monitors each ‘water stream landing zone,’ and by adjusting the appropriate nozzle/monitor/pump combination (including azimuth, elevation, water pressure, spread, modulation, pulsing, etc.), compensates for wind speed and direction - loading Active Windowing, Rapid Modulation of Pump Nozzles- Creating Dynamic Openings in the Water Curtain Useful when synchronized with Radar and other Sensors. - Radar Evasion by Shaped Water Curtain- ----------Full Water Curtain----------------------------Stepped/Folded (Fresnel lens) Arleigh Burke DDG-51 using some Shaped Water Curtains- Active Water Curtain Technology- Array of Powerful Water Pump outlets creating Water Curtain Illustration of Sea Clutter overlaid by Detection Threshold- Targets Detected above the Clutter Linear Nozzle Array- -Omnidirectional Nozzle Array- . Linear Nozzle Array Array shown with one section in up, or operational, position. The external "central feeder pipe" is an indication of the "add on" nature of the AWCT. . End View Diagram Array shown with one section in up, or operational, position. ===============+++======+++===========