Abstract: A computer-implemented method of navigating a vertical take-off and landing (“VTOL”) vehicle near a landing zone, may comprise receiving data related to a first radar signal reflected from at least one corner reflector; determining whether the received data is consistent with a predefined target landing zone; upon determining that the received data is consistent with the predefined target landing zone, determining a location of the VTOL vehicle relative to the predefined target landing zone, using a second radar signal reflected from at least one corner reflector; and determining whether the location of the VTOL vehicle is consistent with a predefined landing position.

Abstract: Many in the space weather community consider our understanding of the buoyancy of the thermosphere and its effects on the orbits of satellites in Low Earth Orbit (LEO) to be insufficient during short time frames. Disclosed herein is an approach for making on-demand thermosphere buoyancy measurements using a deployable low mass retroreflector with CubeSat-like dimensions. A CubeSat storing many retroreflectors can dispense one or more of these passive satellites according to a predetermined schedule or on-command, in response to an observed space weather phenomenon like a coronal mass ejection. With measurements of the orbit decay from these passive satellites, a better understanding of the relationship between space weather and orbital decay can be established with relatively low cost.

Abstract: A corner reflector includes annular balloons, which, when gas is supplied to the inside, annularly expand, and radio wave reflective films each developed to a plane by the expansion of the annular balloons. The three annular balloons are provided so as to be orthogonal to each other in the expansion. A constraint fabric wound around each annular balloon is provided. The constraint fabric includes an inner peripheral side fabric portion located on the side of a virtual central axis of the annular balloon and extending in the annular direction around the virtual central axis, and an outer peripheral side fabric portion located on the side opposite to the virtual central axis and extending in the annular direction. The elongation degree of the outer peripheral side fabric portion in the annular direction is higher than the elongation degree of the inner peripheral side fabric portion in the annular direction.

Abstract: Disclosed herein are polarization and frequency reconfigurable origami-folded antennas and methods for making the same. An origami-folded antenna can include at least one ground plane that can include a dielectric stratum and a conductive stratum that is at least partially disposed on the conductive stratum. The origami-folded antenna can further include at least two helical sections that can include a dielectric sheet and a conductive sheet. The origami-folded antenna can be expanded to an expanded state and compressed to a compressed state along a center axis, and the antenna can have a greater length along the center axis when in the expanded state than when in the compressed state.

Abstract: Chaff is provided for deployment from an aerial platform for retro-reflecting electromagnetic radiation projected to the platform. The chaff includes a plurality of retro-reflecting particles, with each particle being a retro-reflector. The plurality forms a cloud having aerial buoyancy. The particles can be a corner reflector with adjacent sides substantially perpendicular to one another, and in particular a trihedral corner reflector. Alternatively, the particles can be lens reflectors, such as a cat's eye. In addition, chaff is provided for deployment from an aerial platform for retro-reflecting electromagnetic radiation projected to the platform. The chaff includes a plurality of retro-reflecting particles and a substrate. Each particle of the plurality is a retro-reflector. The substrate attaches the plurality of particles.

Abstract: An inflatable RADAR signal device that is capable of rising above the surface of the water when deployed and that reflects RADAR emissions. The signal device is a self-contained, small, independent system that can withstand being present in a maritime environment, including being submerged in the water and/or being located on a vessel in the water, for an extended amount of time. The device includes a housing that houses one or more deflated balloons that are constructed of a material that, when inflated, rise above the level of the water and that reflect RADAR emissions. The device includes at least one gas cylinder for inflating the balloon(s), and a mechanism to trigger release of the balloon(s) from the housing including a mechanism to trigger release of the gas from the gas cylinder(s) to inflate the balloon(s).

Abstract: An influence system including open cell structures with one or more fractal reflective or resonating structures, wherein the fractal reflective or resonating structures are adapted to produce an emitted reflective or resonance signal that approximately matches a target electromagnetic signal reflection or resonance profile comprising a plurality of electromagnetic signal characteristics, said plurality of electromagnetic signal characteristics, a tow yoke coupled to one end of said blanket comprising a floatation chamber section, a tow cable adapted to tow said tow yoke and blanket, said tow cable comprising a low electromagnetic observable material or having a radar absorptive material coating.

Abstract: A remotely deployable, unmanned, inflatable satellite antenna is provided with shock absorbing supports inside a body of the antenna. The shock absorbing supports operatively connect the satellite receiver to the body interior surface and support the satellite receiver inside the body interior while allowing limited movement of the satellite receiver relative to the body interior surface in response to a shock force exerted on the body exterior surface when the antenna is deployed by air drop and impacts with the ground.

Abstract: An antenna includes a dielectric sheet and a conductive film. The dielectric sheet is folded into a plurality of fold segments and is configured to be compressed into a compressed state and to be expanded into an expanded state. The conductive film is disposed on a portion of the dielectric sheet. The conductive film has a pattern that defines a current path from the bottom of the dielectric sheet to the top of the dielectric sheet. The pattern is configured so that the each of the plurality of fold segments includes a portion of the pattern and so that the portion of the pattern on each fold segment is substantially non-juxtaposed with respect to the portion of the pattern on each adjacent fold segment when the dielectric sheet is fully compressed into the compressed state.

Abstract: A corner reflector includes: annular hollow balloons having flexibility and airtightness, and when gas is supplied therein, the annular hollow balloons expand with pressure of the gas to be an annular shape; and a radio wave reflection film having an outer edge part that is attached to the annular hollow balloons so that expansion of the annular hollow balloons makes the radio wave reflection film unfold over a plane of the annular shape. The three of the annular hollow balloons are provided so as to be mutually orthogonal after expansion. Binding members are attached to outer faces of the annular hollow balloons, the binding members being for preventing expansion of the annular hollow balloons beyond their limit volume.

Abstract: A corner reflector includes: a radio wave reflection film having three reflection faces that are mutually orthogonal, and an unfolding device which unfolds the radio wave reflection film three-dimensionally. The corner reflector further includes: a canopy that unfolds concurrently with unfolding of the radio wave reflection film, and the canopy is connected to the unfolding device so as to partially overlie the radio wave reflection film.

Abstract: A self-supporting, readily erectable and transportable mast that includes a pneumatically inflatable elongate tubular member useful for providing structural support when raising various types of equipment above the ground. Included in the tubular member are woven or interwoven textile reinforcing strands arranged in one or more layers that may be laid at various angles useful for reinforcing and strengthening the tubular member when raised.

Abstract: A ship having identifiable radar hot spots along its length is protected against radar homing missile attack by a floating decoy, which may be towed. The decoy has a plurality of radar return signal generators spaced along its length, with the amplitudes and spacing of the generators emulating the amplitudes and spacing of the hot spots. The homing missile is seduced away from the ship and toward the decoy.

Abstract: A corner reflector includes: annular hollow balloons having flexibility and airtightness, and when gas is supplied therein, the annular hollow balloons expand with pressure of the gas to be an annular shape; and a radio wave reflection film having an outer edge part that is attached to the annular hollow balloons so that expansion of the annular hollow balloons makes the radio wave reflection film unfold over a plane of the annular shape. The three of the annular hollow balloons are provided so as to be mutually orthogonal after expansion. Binding members are attached to outer faces of the annular hollow balloons, the binding members being for preventing expansion of the annular hollow balloons beyond their limit volume.

Abstract: A corner reflector includes: a radio wave reflection film having three reflection faces that are mutually orthogonal, and an unfolding device which unfolds the radio wave reflection film three-dimensionally. The corner reflector further includes: a canopy that unfolds concurrently with unfolding of the radio wave reflection film, and the canopy is connected to the unfolding device so as to partially overlie the radio wave reflection film.

Abstract: The present invention relates to a decoy for deceiving Doppler radar systems. The decoy comprises a corner reflector, where at least one of the surfaces (1) is arranged to be able to obtain a varying reflectivity for radar radiation with a modulation frequency, which in the reflected radiation causes Doppler sidebands of an extent that is usual for the radar application.

Abstract: A modular RCS (Radar Cross Section) and IR (Infra-Red) signal generation device includes: a plastic bag which is normally stored in a folded state, and inflated when gas is introduced into the bag as desired; a radar reflector received in the plastic bag, the radar reflector being configured in a multi-hedral reflector structure having a reflection characteristic similar to that of a naval vessel to be protected; hot air tubes formed through the plastic bag, hot air being capable of generating IR signals by flowing through the hot air tubes; and connection patches positioned on one of the surfaces of the plastic bag at the points where the ends of the hot air tubes intersect with the surfaces, respectively, the connection patches being adapted to be attached to those of adjacent modular RCS and IR signal generation devices, respectively, so as to interconnect the hot air tubes with those of the adjacent modular RCS and IR signal generation devices.

Abstract: A chaff element for interfering with radar signals. The chaff element has a dielectric substrate and a pair of elongate electrically conductive elements, having a total length of approximately one-half wavelength of the radar signals or otherwise tuned to the radar signals, disposed on the dielectric substrate. A switch is arranged to electrically couple the pair of elongate elements together in response to a control signal generated by an oscillator circuit and a battery. The chaff element can be used in a method of providing a countermeasure against radar signals. A plurality of chaff elements can be deployed in an airspace above a radar unit emitting a radar signal and interfere with the radar signal by opening and closing the switches of the chaff elements while deployed in said airspace above the radar unit.

Abstract: A high frequency signal calibration target deployable in outer space includes an expandable and electrically conductive symmetric structure. The structure may mechanically expand from a stowed configuration to a deployed configuration. Scatter of high frequency signal off of a substantially symmetric signal calibration target may be measured to accurately calibrate systems using high frequency signals.

Abstract: A buoyant target comprises an inflatable structure with a drogue chute attached to the periphery of the bottom of the inflatable structure. The drogue chute is an open flexible structure with a bottom end weighted with ballast to deploy it, and with ports through its side to permit water to flow into and out of it. A radar reflector device is attached inside the inflatable structure. The radar reflector device comprises a plurality of mutually orthogonal radar reflective surfaces having central reflection vectors pointed at predetermined directions.

Abstract: The present invention relates to a decoy for deceiving radar systems, especially Doppler radar systems. The decoy comprises a corner reflector, where at least one of the surfaces (1) is arranged to be able to obtain a varying reflectivity for radar radiation, especially with a modulation frequency which in the reflected radiation causes Doppler sidebands of an extent that is usual for the radar application.

Abstract: A submarine warfare radar training system 10 includes an underwater vehicle 15 towing a float device 40 and a radar reflective target 45. The radar reflective target 45 is configured as a hollow tube-shaped element 50 having circular open leading and trailing open circular end to allow water to flow through the target as it is towed. The target 45 includes a positive buoyancy material layer 60 and is horizontally oriented during towing. The float device 40 is configured to support the radar reflective target 45 open leading end above the water surface 30 as the float device 40 and radar reflective target 45 are towed along the water surface to deliver air into the hollow cross-section. The radar reflective target 45 has an adjustable RCS which can be increased or decreased by lengthening or shortening the radar reflective target.

Abstract: A radar reflector which can be deployed from an aircraft and is intended to fly freely after deployment, and which includes multiple reflector surfaces that are essentially plane in an operative state and which issue in pairs in opposite directions from an essentially plane base plane. The radar reflector before deployment can be stored compactly, packed up into the minimum possible volume. This facility for packing the radar reflector up has been achieved in that its reflecting main surfaces have each been divided up by means of specially aligned buckled folds into a plurality of parts which can be folded in towards one another when the reflector is to be folded up.

Abstract: A phased array balloon antenna having an inner membrane coupled to an outer membrane and a phased array antenna connected to an inner membrane. The phased array antenna transmits an energy towards a reflective film on the outer membrane, reflecting the energy outwards and illuminating an area smaller than that illuminated by the phased array alone.

Abstract: The present invention involves an inflatable antenna system including an inflatable antenna and a mounting plate. The inflatable antenna includes an inflatable cone or cylinder and a plurality of conductors integrated therein. The mounting plate can be incorporated into a protective enclosure that holds and protects the inflatable antenna during transport, supports it during use, and provides a means for mounting it to a mast. The mounting plate serves as a mounting surface for the inflatable antenna, a radio frequency (RF) connector, an air intake valve, and an impedance matching network. Selected surfaces of the protective enclosure can be coated with conductive materials. An air intake valve allows for inflation and deflation of the inflatable antenna. Inflatable support members can be used in conjunction with a stabilizing portion comprised of a vertical member and attached weight, to allow the inflatable antenna system to be deployed in water.

Abstract: A large aperture lightweight antenna uses an inflatable spherical surface deployed within a lighter than air platform. Beam steering is accomplished by moving the RF feedpoint(s) with respect to the reflector. The antenna can use an inflatable collapsible transreflector.

Abstract: An antenna directivity enhancer to enhance the directivity of an antenna is disclosed. The enhancer has a 3-dimensional structure in a predefined 3-dimensional shape when operating to enhance the directivity of an antenna. The 3-dimensional structure can be flexibly collapsible into 2-dimensional flat surfaces, with at least two of the surfaces not required to have any space between them when the structure is collapsed. The direction where the directivity is enhanced can be changed as desired. The enhancer can include just one reflecting surface, or at least two reflecting surfaces. In yet another embodiment, the enhancer includes a curved surface when the enhancer is in its predefined 3-dimensional shape.

Abstract: An inflatable, multifunction, multipurpose, parabolic reflector apparatus 10 having a plurality of manufactured parabolic mirrors 14, 16 made from a pressure-deformable reflective covering of an inflatable ring 12 for focusing electromagnetic energy from radio frequency radiation (RF) through the ultraviolet radiation (UV) and solar energy for (1) heating and cooking, for (2) electrical power generation, for (3) enhancing the transmission and reception of radio signals, for (4) enhancing vision in low-light environments, and for (5) projection of optical signals or images. The device also has non-electromagnetic uses, such as the collection of water. A first main embodiment utilizes two reflective membranes. A second main embodiment utilizes a reflective membrane and a transparent membrane. Portability is enhanced by complete collapsing of the inflatable device.

Abstract: The present invention provides an electromagnetic reflector comprising a deployable support frame carrying at least one sheet element designed to form a reflective surface when in the deployed state, wherein the support frame comprises a band that is suitable for being packaged in a folded state and that is suitable for returning to a deployed state in the absence of external constraint, the band being in the form of three rings that are orthogonal in pairs, and the reflector further comprising eight generally triangular panels of sheet material.

Abstract: Radar reflective rescue and safety devices comprise radar permeable coverings around a plurality of reflectors. The radar reflective material may be incorporated into inflatable life vests or foam filled life vests. Additionally, inflatable life rafts with radar reflective cells are able to help personnel lost at sea to be found by radar. The radar reflective cells may also be incorporated into an inflatable cylindrical tube as radar cross-section enhancer separate from other flotation devices. The reflectors are flexible metallic material that forms reflective cavities once the shell is inflated. The reflective cavities may appear as flat surfaces, tilted surfaces, corner reflectors or some combination thereof depending upon the orientation of the cavities to an incident radar wave.

Abstract: A Radar Counter Measure System (RCMS) and method for operating a decoy as a Radar Counter Measure (RCM) against incoming airborne threats, wherein the RCMS consists of an airborne vehicle (6) carrying a payload (8) launched from a platform (2) by a launcher (4). The payload contains one or more decoys. Each decoy includes a folded corner reflector construction (CRC) (14) which is released at a predetermined point on the vehicle's trajectory. The vehicle is launched by a gun (26), a mortar (20), a rocket (32) or another airborne device. Once released, the decoy is deployed and self-erected to become effective as a RCM. The self-erection mechanism (12) is mechanical, pneumatic, pyrotechnic or aerodynamic. The payload (8) may hold various kinds of counter measure devices.

Abstract: The present invention relates to a device forming an electromagnetic reflector comprising a deployable support frame (100) carrying at least one cloth element (200) designed, in the deployed state, to form a reflective surface, the device being characterized by the fact that the deployable support frame (100) comprises at least one deployable arm (120) that is telescopic.

Abstract: There is provided a radar reflector apparatus that is mounted in a lifeboat or a small rescue boat or in a floating buoy used for salvage or search practice, or is used by itself independently, to serve as a radar wave reflector of a search radar. The radar reflector apparatus has a simple structure, and is folded when not in use, and when used, is unfolded automatically when dropped by a marine vessel or aircraft or the like.

Abstract: An inflatable antenna has a plurality of inflatable tori including a first toroidal member and a second toroidal member arranged one radially inward of the other. A front membrane having a reflective coating is attached to the plurality of tori to form a front reflective surface. A rear membrane is attached to the plurality of tori and provides a rear support surface. The inflatable reflector is lightweight and compact and can be easily inflated to a desired shape.

Abstract: The present invention relates to a device forming an electromagnetic reflector comprising a deployable support frame (100) carrying at least one cloth element (200) designed, in the deployed state, to form a reflective surface, the device being characterized by the fact that the deployable support frame (100) comprises at least one deployable arm (120) that is telescopic.

Abstract: The present invention provides an electromagnetic reflector comprising a deployable support frame carrying at least one sheet element designed to form a reflective surface when in the deployed state, wherein the support frame comprises a band that is suitable for being packaged in a folded state and that is suitable for returning to a deployed state in the absence of external constraint, the band being in the form of three rings that are orthogonal in pairs, and the reflector further comprising eight generally triangular panels of sheet material.

Abstract: A polyhedral-shaped inflatable structure having substantially continuous inner and outer flexible surfaces is inflatable with air or gas so that a radar reflector, comprising a plurality of conterminous corner reflectors, is thereby positioned within the inflatable structure to reflect radar waves. The corner reflectors are preferably made of metallized reflective plastic film attached to a plurality of support filaments. Support members attached to the support filaments are pivotally disposed adjacent to the inner flexible surface to position the radar reflector within the inflatable structure. Removable fasteners are disposed adjacent to the outer flexible surface and concentrically proximate to the support members to thereby fasten the radar reflector to the inflatable structure without puncturing the inner and outer flexible surfaces.

Abstract: A radar detectable balloon includes an inflatable envelope with several planar radar-reflecting surfaces. Prior to inflation, the balloon may be collapsed into a compact flat configuration. When inflated, the radar reflective planar faces arranged in such a way that the largest angle formed by every line of sight and a normal to at least one planar face is less than 45°.

Abstract: An emergency passive radar locating device for use by missing persons or craft to enhance their survivability in a search and rescue operation. The emergency passive radar locating device comprises an array of eight radar corner reflectors. Each corner reflector of the emergency passive radar locating device has three radar signal reflective surfaces which are mutually perpendicular. When fully inflated the emergency passive radar locating device is spherical in shape with three mutually perpendicular toroidal flotation rings.

Abstract: A detection system for small water craft, such as a kayak. Radar reflective material is incorporated in the surface of the kayak or other water craft, and also is incorporated in surface areas of water craft accessories, such as cushion, life vest or paddle. When the smaller water craft is in the vicinity of a larger aircraft which may be radar equipped so that there is danger of a collision or where the water craft is in a position where it would want detection as part of a rescue effort or the like, the water craft is oriented so that the radar reflective surface would reflect radar back to the sending source, thus better enabling detection. Also, the paddle or other water craft accessory could be positioned so as to reflect the radar waves. Further, the paddle or other accessory could be oriented to reflect the radar waves back to the source, or do so intermittently, in the event that the radar system is programmed to ignore a constant reflective signal.

Abstract: This invention is directed to a apparatus that includes an inflatable antenna reflector assembly for generating electromagnetic plane waves. The apparatus can be used in a variety of applications in which plane waves are beneficial, such as in a compact range to simulate the long-range behavior of a radar system to test a target for its radar signature. The inflatable reflector assembly of the apparatus includes a base, an arched frame mounted to the base, and an envelope-like cover that fits over the frame. The cover's front side is transmissive to electromagnetic waves, and its rear side is reflective to such waves. The apparatus can include a point source antenna feed, in which case the cover's reflective portion is made to be parabolic, or the antenna feed can be a line source, in which case the cover's reflective portion is spherical. The base can be rested directly on the floor or ground for support.

Abstract: Three reflector plates comprising: a lateral reflector plate having two half plates each opposingly placed across a rotation supporting shaft introduced therebetween, a longitudinal reflector plate having two half plates each opposingly placed across the rotation supporting shaft therebetween, and a bottom reflector plate placed at the central portion of the rotation supporting shaft, wherein these three reflector plates are brought into mutual orthogonal intersection at their diameters, and the rotation supporting shaft is provided with an inclination supporting hole with an inclination of a "detection design angle", thereby enabling to maintain the detection design angle when in use and enabling to easily assemble into the shape for use even in case of emergency, and further enabling the reflector plates to be stacked flat one upon another and stored free from bulkiness when not in use.

Abstract: Inflatable radar reflectors comprising three mutually orthogonal radar reflective planes incorporated within the structure thereof can take the form of a teardrop, a cylindrical drogue or a set of three intersecting discs. A preferred embodiment includes three inflatable hollow toruses of flexible material which mutually intersect in a manner such that their planes are mutually orthogonal and each intersection provides a passage for air to pass between the intersecting sections thereof, inflation means for filling the three toruses simulataneously and collapsible circular panels of radar-reflective material covering each torus so that they form mutually orthogonal radar reflective planes. The preferred embodiment can be encased in a radar permeable balloon.

Abstract: An improved omnidirectional radar retroreflector and marine personal locator incorporating same. One embodiment of the radar retroreflector includes first and second collapsible radar reflective disc portions biased in a substantially perpendicular open position with a plurality of radar reflecting web sections extending substantially perpendicularly therebetween creating eight sets of three mutually-perpendicular radar reflective surfaces forming an omnidirectional radar retroreflector. In a collapsed position, the first and second disc portions bend around a common axis of intersection in a non-destructive manner folding the web sections.

Abstract: A system and method for providing interactive multimedia services to subscriber premises utilizing wireless distribution within the subscriber premise. The service is provided via a communications link delivering to the subscriber premises broad band digital information including video and audio from a plurality of information providers and control signals in a multiplexed form. This multiplexed signal is then separated and processed on premise and distributed in a two-way fashion using frequency hopping code division multiple access (CDMA) spread spectrum using radio frequency signals preferably at UHF. Upstream control signals from the user installation are communicated from the individual user terminals in the same wireless manner.

Abstract: An apparatus and method for providing small size, high gain corner reflection of radio frequency signals for use in military and commercial applications. Conventional corner reflector practice is combined with electronic amplifying reflection devices such as the superregenerative amplifier to provide an array of antennas and amplifiers spread over each planar surface of a corner reflector. The specific antenna used may be selected from a plurality of various antenna types depending on the application. As in a conventional corner reflector, the amplified signal is reflected at the same angle and in the opposite direction of the incident signal.

Abstract: Distress signal kits comprise a parafoil for carrying aloft various emergency or distress signals such as radar reflective materials, lights, flares, distress flags or smoke signals. Preferably the parafoil itself is colored International orange and contains a U.S. Coast Guard-approved distress signal (BLACK SQUARE AND CIRCLE) on both top and bottom surfaces. The parafoil can be used to raise a spinnaker sail attached to a vessel or swimmer. The spinnaker can also carry radar reflective components and/or distress flags, and can be fitted for other survival uses.

Abstract: A method for stowing a unitary flexible antenna reflector 10 in a confining envelope and deploying the reflector from the envelope. In a most general sense, the invention includes the steps of: a) applying a deforming force to diametrically opposed positions 16 and 18 near an edge of the reflector 10 to place the reflector in a deformed state; b) maintaining the reflector 10 in the deformed state until deployment; and c) releasing the reflector 10 from the deformed state. In a specific embodiment, the step of maintaining the reflector 10 in a deformed state includes the step of attaching a restraining element between the diametrically opposed positions on the edge of the reflector which is released on deployment.

Abstract: Distress signal kits comprise a parafoil for carrying aloft various emergency or distress signals such as radar reflective materials, lights, flares, distress flags or smoke signals. Preferably the parafoil itself is colored International orange and contains a U.S. Coast Guard-approved distress signal (BLACK SQUARE AND CIRCLE) on both top and bottom surfaces. The parafoil can be used to raise a spinnaker sail attached to a vessel or swimmer. The spinnaker can also carry radar reflective components and/or distress flags, and can be fitted for other survival uses.

Abstract: A coating composition for the attenuation of the reflection electromagnetic radiation and particularly electromagnetic radiation have a wavelength of greater than 800 nm including the near infrared is described. The composition comprises a chromophore capable of absorbing up to about 95% of the electromagnetic radiation having a wavelength greater than 800 nm. Optionally, the composition may comprise microbeads that serve the purpose of also scattering the electromagnetic radiation.