Mechanical-based modulation of electromagnetic (EM) fields has been studied for some time. EM modulation occurs naturally in the form of a Bragg-line high frequency scattering response from ocean surfaces. Attempts to engineer a similar response have resulted in studies involving the motion of helicopter blades and wind turbine blades to control EM radiation properties. Other attempts have focused on the detection of Doppler velocity shifts in the ultrasound and acoustic regimes, rather than on engineering a surface with a controllable response.
Additionally, the intersection between ocean dynamics and seagoing ships has an incredibly rich history ranging from early seagoing studies of the 1890s to computer animation to wave pools. Described herein is a complementary approach through the implementation of a dynamic, mechanized surface, with one embodiment representing a time-resolved, fully-developed sea. Gerstner theory, or trochoid wave theory, describes wave motion with water particles moving along circular orbits. The dynamics of the circular orbits are mapped to linearly actuated motion using a correction factor for the ocean height and velocity at a given point in time and space. The ocean is implemented as a two-dimensional trochoid surface and controlled using a dense array of microprocessors, sensors and actuator systems. Actuation is achieved through slide potentiometers. Time-resolved wave motion on this mechanized surface is demonstrated for sinusoidal and trochoid waves. The positions of wave heights and velocity are measured using time-of-arrival sensors. The feasibility of using a mechanized ocean surface is evaluated for heave experiments in ship design.
Reference in the specification to “one embodiment” or to “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment. The appearances of the phrases “in one embodiment”, “in some embodiments”, and “in other embodiments” in various places in the specification are not necessarily all referring to the same embodiment or the same set of embodiments.
Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or.
Additionally, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the invention. This detailed description should be read to include one or at least one and the singular also includes the plural unless it is obviously meant otherwise.
Graphs 110 and 120 first develop a physical environment. The numerical representation of a physical environment considers the size of the fluid region and the number of representative sample points. The fluid region is taken to be either a single line of fluid particles (2-D case seen in graph 120) or a grid (3-D case seen in graph 110). In either case, the region is planar with no depth at rest. Thus, the models in
The number of sample points is chosen so as to sufficiently describe a wave propagating through the fluid region. The models in
The models in
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This application is a nonprovisional application claiming priority to U.S. Patent Application Ser. No. 62/693,058, filed on Jul. 2, 2018, entitled “System and Method For Adaptable Electromagnetic Doppler Surface,” the entire content of which is fully incorporated by reference herein.
The System and Method for Adaptable Electromagnetic Doppler Surface is assigned to the United States Government and is available for licensing for commercial purposes. Licensing and technical inquiries may be directed to the Office of Research and Technical Applications, Space and Naval Warfare Systems Center, Pacific, Code 72120, San Diego, Calif., 92152; voice (619) 553-5118; email ssc_pac_T2@navy.mil. Reference Navy Case Number 104009.