Abstract: Systems, devices, and methods for an aircraft autopilot guidance control system for guiding an aircraft having a body, the system comprising: a processor configured to determine if a yaw angle difference and a pitch angle difference meet corresponding angle thresholds; a skid-to-turn module configured to generate a skid-to-turn signal if the corresponding angle thresholds are met; a bank-to-turn module configured to generate a bank-to-turn signal having a lower bandwidth than the generated skid-to-turn signal; a rudder integrator module configured to add a rudder integrator feedback signal to the bank-to-turn signal, where the rudder integrator feedback signal is proportional to a rudder integrator; and a filter module configured to filter the generated bank-to-turn signal, wherein the filter module comprises a low-pass filter configured by a set of gains to pass the bank-to-turn signal if a side force on the body meets a side force threshold.

Abstract: A powered projectile having a nose portion, a body portion, a tail portion, and a central axis. In various embodiments a collar is rotatably mounted to a control support portion with a plurality of aerodynamic surfaces thereon for despinning the collar. An alternator configured as an axial flux machine with a stator arranged can be axially adjacent to one or more rotors, the stator including a plurality of windings and the one or more rotors each including a plurality of permanent magnets arranged about the face of the respective one or more rotor. In various embodiments the projectile includes an assembly of projectile control circuitry. In one or more embodiments, upon relative motion of the rotor with respect to the stator, magnetic flux from the magnets interacts with the windings of the stator and passes through an air gap between the one or more rotors and stator.

Abstract: A closed, self-contained ballistic apogee detection module for use in a projectile, such as a rocket, mortar round, or artillery round, fuses data from multiple built-in sensors, such as an accelerometer, a magnetometer, and a gyroscope, and processes the data using a microprocessor through a custom quaternion extended Kalman filter to provide accurate state and orientation information about the projectile so as to accurately predict apogee. The module outputs a signal indicating apogee detection or prediction which they projectile uses to initiate fuze arming, targeting control, airbody transformation, maneuvering, flow effector deployment or activation, payload exposure or deployment, and/or other mission activity. Because the system and method of the invention does not rely on external environmental data to detect apogee, it need not use a pressure sensor and can be completely sealed in and closed without requiring access to air from outside the projectile for barometric readings.

Abstract: An aero wind power generation apparatus includes: a drone unit including drone wings configured to make the aero wind power generation apparatus move and hover and a sensor unit configured to detect information for controlling the aero wind power generation apparatus; a buoyancy generation unit connected to the drone unit and including a side cover configured to open or close and a balloon provided inside the side cover, wherein the buoyancy generation unit is configured to enable injection of gas into or release of the gas from the balloon; and a power generation unit connected to the buoyancy generation unit and including a rotating unit with a plurality of blades, a blade control unit of adjusting the state of the blades, and a motor unit of converting kinetic energy transferred from the rotating unit into electrical energy.

Abstract: Launching an aeronautical system can comprise applying force or energy to the system in connection with accelerating the system. Responsive to the force or energy, an element of the system can move along a defined path within the system. The system can comprise a drive that converts motion along the defined path into rotational motion. The drive can rotate a mass within the system, which can be supported by a gas bearing. The rotating mass can comprise the moving element, a different system element, or the entire system. The rotating mass can produce angular momentum and can support gyroscopic stabilization of the aeronautical system. Rotational energy can be selectively imparted to and transferred between system elements in connection with stabilization management. System elements can moderate the system's response to impulsive stimuli associated with rotation and acceleration. A gas bearing can support an external surface of the system during launch.

Abstract: A guided projectile including a precision guidance munition assembly utilizes at least one maneuver envelope to optimally control movement of at least one canard to steer the guided projectile during flight. The maneuver envelopes optimize movements of the at least one canard that effectuate movement in either the range direction or the cross-range direction, or both. The maneuver envelope enables optimal timing such that maneuvering in one direction does not come at the expense of maneuver authority in the other direction.

Abstract: According to a first aspect of the invention, there is provided an object for moving through a fluid, the object comprising: an outer housing, arranged to be exposed to a hydrostatic pressure exerted by the fluid; a strain gauge, arranged to obtain an indication of the hydrostatic pressure, wherein a first part of the strain gauge is arranged to be in contact with the outer housing, such that the strain gauge is arranged to obtain an indication of the hydrostatic pressure by obtaining an indication of the strain on the housing.

Abstract: A processing unit includes a direction decision unit and a guide information generation unit. The direction decision unit decides a direction in which a person who behaves without a sense of sight walks. The guide information generation unit generates guide information for the person who behaves without the sense of sight to walk in the decided direction. The present technology is applicable, for example, to a smartphone or the like used by the person who behaves without the sense of sight.

Abstract: A technique of managing communications among multiple modules of a munition includes receiving, by a first module of the munition, a first set of messages from a second module of the munition. The first set of messages is received in a first protocol used for communicating among the modules of the munition over a computer network. The technique further includes translating, by an interface assembly of the first module, the first set of messages in the first protocol into a second set of messages in a second protocol. The second protocol is a native protocol of the first module and is different from the first protocol. The technique still further includes providing the second set of messages from the interface module to an operational component of the first module, the operational component then responding to the second set of messages for performing a function of the munition.

Abstract: A tethered aircraft or balloon carrying a communications base station for rapid deployment in emergency situations. Electrical power is delivered from a generator on the ground using a pulsed electrical supply system in which each power pulse is delivered over a cable and acknowledged, and pulses only continue to be delivered whilst such acknowledgements are received by the ground station. This reduces the risks associated with delivering electrical power over an aerial tether, and avoids the need for an earth (ground) connection, reducing the risk from lightning.

Abstract: A drone may receive power from mobile base station equipment via an air-to-ground power feed during flight, which allows the drone to remain in flight for longer periods of time than relying on battery power alone. The air-to-ground power feed may be included in a tether that includes multiple air-to-ground power feeds or communication feeds. In some cases, the drone is powered by an on-board power system during takeoff and landing sequences to avoid damage to the tether or the drone and/or signal interference within the tether. In some cases, the drone may follow flight patterns during takeoff and landing sequences to avoid damage to the tether or the drone and/or signal interference within the tether.

Abstract: The communication apparatus (1100) configured to be installed in a first aircraft (1b) comprises a controller (1110) and a transmitter (1106). The controller (1110) is configured to acquire resource information and determine a communication condition based on the resource information, the resource information being related to a second aircraft (1a) different from the first aircraft (1b) or to a radio altimeter installed in the second aircraft (1a). The transmitter (1106) is configured to transmit transmission data to one other communication apparatus installed in the first aircraft (1b), according to the communication condition.

Abstract: An aero vehicle with a dual mode propulsion system that can operate in a first mode below a ramjet speed and a second mode at a ramjet speed. The first mode is operated using a compressor driven by an electric motor supplied with electrical power from a power pack. When the vehicle has reached a speed where the ramjet engine can operate, the power pack is dropped from the vehicle to decrease the weight of the vehicle.

Abstract: A system for finding up in a projectile flight relative to earth. The system having a transmitter which transmits polarized reference signals to a guidance sub-system on the projectile. The guidance sub-system includes a magnetometer and polarized and non-polarized receivers. Measurements from the magnetometer are used to determine a general up direction. The polarized and non-polarized receivers are arranged such that, during rotation of the projectile, reference signals received by the polarized receiver modulate whereas reference signals received by the non-polarized receivers are unaffected. A ratio of the strengths of the signals received by the polarized and non-polarized receivers determines alignment of a vertical axis. From the general up direction and alignment of the vertical axis, a precise up direction of the projectile in flight relative to the earth can be determined.

Abstract: An optical tracking system may comprise a reference marker unit stationarily disposed relative to a patient, a shape measurement unit configured to measure the three-dimensional shape of a specified part of the patient corresponding to a three-dimensional image, a tracking sensor unit configured to sense the reference marker unit and the shape measurement unit, and a processing unit. The processing unit may acquire a coordinate transformation relationship between the reference marker unit and the tracking sensor unit and a coordinate transformation relationship between the shape measurement unit and the tracking sensor unit based on a sensing result of the tracking sensor unit, acquire a coordinate transformation relationship between the specified part of the patient and the shape measurement unit based on a measurement result of the shape measurement unit, and define a coordinate system of the patient relative to the reference marker unit from the acquired coordinate transformation relationships.

Abstract: The system and method for EO/IR and RF sensor fusion and tracking using a dual extended Kalman filter (EKF) system provides a dynamic mixing scheme leveraging the strength of each individual sensor to adaptively combine both sensors' measurements and dynamically mix them based on the actual relative geometries between the sensors and objects of interest. In some cases the objects are adversarial targets and other times they are assets.

Abstract: Iterative methods for direction of arrival estimation of a signal at a receiver with a plurality of spatially separated sensor elements are described. A quantized estimate of the angle of arrival is obtained from a compressive sensing solution of a set of equations. The estimate is refined in a subsequent iteration by a computed error based a quantized estimate of the direction of arrival in relation to quantization points offset from the quantization points for the first quantized estimate of the angle of arrival. The iterations converge on an estimated direction of arrival.

Abstract: A method, computer program product, and customized image processing system provide aided target recognition (AiTR) using manifold transfer substance learning (MTSL). The method includes receiving image data. The method includes performing manifold learning technique comprising diffusion mapping on the received image data to transform the received image data. The method includes applying a transfer subspace learning technique comprising Transfer Fishers Linear Discriminative Analysis (TrFLDA) to the transformed data to recognize an object within the image data.

Abstract: Techniques are provided for determination of a guided-munition orientation during flight based on lateral acceleration, velocity, and turn rate of the guided-munition. A methodology implementing the techniques, according to an embodiment, includes obtaining a lateral acceleration vector measurement and a velocity of the guided-munition, and calculating a ratio of the two, to generate an estimated lateral turn vector of the guided-munition. The method also includes integrating the estimated lateral turn vector, over a period of time associated with flight of the guided-munition, to generate a first type of predicted attitude change. The method further includes obtaining and integrating a lateral turn rate vector measurement of the guided-munition, over the period of time associated with flight of the guided-munition, to generate a second type of predicted attitude change.

Abstract: A method for determining a direction of a spin axis of a rotating apparatus which includes an XYZ-magnetic field sensor. The method includes determining a global direction of a magnetic field; rotating the rotating apparatus around the spin axis, measuring at least one magnetic field value as a function of time with the XYZ-magnetic field sensor when the rotating apparatus is rotating about the spin axis, computing a magnetic field component of the magnetic field in a direction of a local body co-ordinate of the spin axis of the rotating apparatus from the measured at least one magnetic field value and determining a direction of the spin axis using the computed magnetic field component of the magnetic field and the determined global direction of the magnetic field.

Abstract: The present invention is directed to a bendable projectile having a forebody unit, a rearbody unit and an articulating joint unit connecting the two units. The articulating joint unit is composed of a spherical shape body, a receiving socket and a sphere-gear assembly. The spherical shape body is fitted into the receiving socket whereby movement of the spherical shape body about the receiving socket is permitted without release of the spherical shape body from the socket. Movement of the spherical shape body inside the receiving socket is effectuated by the sphere gear assembly. The sphere-gear assembly engages the concentric grooves along the surface of the spherical shape body or the concave surface of the receiving socket. Such sphere-gear assembly is comprised of electric board, powersource, powertrain, guidance control system and gears having teeth and grooves that complement the plurality of concentric grooves on the spherical shape body.

Abstract: A Lidar system is provided. The Lidar system may comprise: a plurality of light sources configured to emit a plurality of light beams, the plurality of light sources are mounted to a first mounting apparatus comprising a cooling feature; a plurality of optical fiber elements, and each of the plurality of light sources is optically coupled to an input end of one or more optical fiber elements from the plurality of optical fiber elements; and a second mounting apparatus comprising at least one mounting unit coupled to an emitting end of the plurality of optical fiber elements, and the at least one mounting unit is configured to control an output direction of the plurality of light beams individually, and a distribution pattern of the plurality of light beams emitted from the emitting end of the plurality of optical fiber elements.

Abstract: Described is a computer-implemented method of additive manufacturing of a three-dimensional part. The method includes obtaining a surface representation of a 3D part in a 3D scene, the surface representation being enclosed inside a bounding volume, discretizing the scene into voxels, forming an unsigned distance field by storing a minimal distance value to the surface representation of the part for each voxel, determining one or more voxels located outside the bounding volume, the one or more voxels located outside the bounding volume being associated with a label, propagating by flood filling the label until a stopping condition is met, which is reaching a gradient inversion of the distance field, inverting the sign of the distance value of all unlabeled voxels so as to obtain a signed distance field, computing an iso-surface of the part at iso-value zero based on the signed distance field, and additive manufacturing the part.

Abstract: An imaging apparatus 20 includes an image sensor 22 and a controller 33. The image sensor 22 is configured to capture a rear area behind a vehicle 50 and generate a first video image. The controller 33 is configured to synthesize a guide wall image 80 that indicates a predicted path of the vehicle in a display region of the first video image.

Abstract: A component-based system and method is provided for generating and processing multi-dimensional gridded mesoscale meteorological projections. In embodiments, the system includes four integrated processes for data storage, retrieval, manipulation, communication, processing, and end user application tasks. Two or more components may interface for performing tasks. A data component stores, retrieves, and manipulates data utilizing functions under conditions of variable internet and non-internet connectivity. A communications component transmits and receives data to/from the data component for manipulation by the processing component. The processing component includes an artificial intelligence machine learning component and logic for manipulating the data to generate gridded mesoscale meteorological projections arrayed spatially and temporally.

Abstract: An apparatus includes a capsule configured to be launched or carried towards an unmanned aerial vehicle (UAV). The apparatus also includes a directed energy device within or carried by the capsule. The directed energy device includes a first inductor configured to generate an inductive magnetic field that is able to inductively couple into one or more electronics of the UAV in order to disable or destabilize the UAV. The capsule can be configured to be launched towards the UAV and can include a loiter mechanism (such as a rotor, umbrella, or parachute) configured to maintain a position of the capsule or to slow a descent of the capsule after launch. The capsule can also be configured to be carried towards the UAV by a different UAV, and the apparatus can further include a tether coupling the capsule to the different UAV.

Abstract: A projectile including a body having a tip and a tail, the body also having an internal cavity. There is at least one plume aperture connected to the internal cavity, the plume aperture being positioned proximate to the tip of the body.

Abstract: A computer-implemented analysis method is provided for determining range of a ballistic missile for inclusion into a retaliatory targeting system. The method includes receiving and initializing input variables of the missile; calculating constants from the missile; determining completion of boost interval calculations; determining burnout parameters: velocity, flight path angle, and ground range at completion of boost interval for multiple stages; calculating orbital range from the burnout constraints; determining reentry intervals from which to calculate velocity and reentry range; summing boost, orbital, and reentry range values upon interval completion; and summing boost, orbital, and reentry times upon interval completion.

Abstract: For evaluating navigation information based on line-of-sight measurements, a method measures a line-of-sight measurement with an imager. The method further calculates an information metric based on the line-of-sight measurement. The information metric is a function of imager pixel measurement noise and a relative position vector for an imager frame aligned with a focal plane frame for the imager. The method evaluates navigation information using the information metric.

Abstract: Accessories may be mounted using a quick-detachable multi-purpose accessory mounting platform. The platform may include one or more clamps to receive an object, such as a firearm. The platform also may include at least one recessed mounting pad, at least one rear shelf, and other surfaces to provide different mounting points for accessories.

Abstract: Disclosed is an energy beam interceptor that includes an interceptor vehicle of either a missile or a lighter than air vehicle that carries an energy beam generator with a minimum power output of approximately 500 W, a high density power supply that power the energy beam generator, an energy beam targeting apparatus that directs emissions from the energy beam generator and an energy beam targeting controller that targets emissions from the energy beam generator with the energy beam targeting apparatus.

Abstract: The present invention discloses a GNSS-INS vehicle attitude determination method based on a single antenna, including the steps as below: mounting a GNSS antenna at a centroid and in the center of the vehicle, and mounting the IMU measuring unit of the MEMS sensor on the steering shaft of the vehicle; obtaining the position and velocity information of the vehicle by means of the GNSS antenna, obtaining the heading angular speed information of the vehicle by means of the IMU measuring unit; calculating the attitude angle of the vehicle by means of the combination with accelerometer and gyroscope; calculating the heading angle of the vehicle based on the position, velocity, and heading angular speed of the vehicle. The method combines the advantages of the short-term high precision of the IMU gyroscope and the long-term high stability of the GNSS single antenna, so as to avoid the divergence phenomenon.

Abstract: A spatially-distributed architecture (SDA) of antennas transmits respective uniquely coded signals. A first receiver having a known position in a coordinate system defined by the SDA receives reflected versions of the uniquely coded signals. A first processor receives the reflected versions of the uniquely coded signals and identifies a position of a non-cooperative object in the coordinate system. A platform with a platform receiver receives non-reflected versions of the uniquely coded signals. The platform determines a position of the platform in the coordinate system. In an example, the platform uses a self-determined position and a position of the non-cooperative object communicated from the SDA to navigate or guide the platform relative to the non-cooperative object. In another example, the platform uses a self-determined position and information from an alternative signal source in a second coordinate system to guide the platform. Guidance solutions may be generated in either coordinate system.

Abstract: Fluoride-based nanocomposite materials, optical articles made therefrom, and methods of making the fluoride-nanocomposite materials and optical articles. In certain examples, a fluoride-based nanocomposite material includes two or more interspersed fluoride-based nanograin materials with grains having one, two, or three dimensions that are less than 1 micrometer.

Abstract: Methods and systems are provided for aligning an inertial measurement unit (IMU) of a vehicle. In one embodiment, a system includes a sensor device configured to provide sensor data associated with an environment of the vehicle. The system further includes a sensor data processing module configured to process the sensor data to determine a ground plane and a vertical plane in the environment of the vehicle. The system further includes a correction module configured to determine at least one of a pitch and a roll alignment value based on the ground plane and the vertical plane.

Abstract: An apparatus for in-situ testing of a linear actuator configured to exert an actuation force in an actuation direction by movement of a first part of the actuator relative to a second part of the actuator. The apparatus includes a test device, a test actuator and a measurement device. The test device includes a first surface configured to contact the first part of the actuator, and a second surface configured to contact the second part of the actuator. The second surface is moveable relative to the first surface to alter a distance therebetween. The test actuator is configured to exert a test force in a direction opposite to the actuation direction, the test force being to drive movement of the second surface away from the first surface. The measurement device is for detecting a change in the distance between the first surface and the second surface.

Abstract: An optical system configured to counteract vibrations due to a munitions launch includes a cylindrical optical lens stack. The system also includes an accelerometer attached to the lens stack and connected to a control system and power supply. The system further includes a mechanical actuator attached to the lens stack and connected to a control system and power supply. The mechanical actuator is a piezoelectric actuator.

Abstract: An apparatus and method that improves the operation of aerospace planes or rockets having an integrated flute and hat components whereby the flute functions as a hypersonic refrigeration engine and the hat as a flat plate heat exchanger to achieve an isothermal compression of the incipient hypersonic air in front of the nosecone to reduce hypersonic vibrations during flight, these improvements allow for the reduction in temperature during flight operation allowing for improved cooling of the aerospace plane or rocket.

Abstract: Various systems may benefit from the appropriate interworking of subsystems. For example, various avionics systems and method may benefit from the integration of terrain and/or weather avoidance, for example with other detection and avoidance subsystems. A method can include determining, by an avionics system, a hazard condition with respect to an ownship aircraft. The method can also include generating, by the avionics system, a maneuver inhibition based on the determined hazard condition. The method can further include providing the maneuver inhibition to a traffic avoidance or alerting system.

Abstract: Precision ballistic airdrop of packages from an aircraft comprises entering the estimated wind field in the drop zone into a CPU aboard the packages; computing a transition altitude for each of the packages based on the wind field and the order in which each package is released, each package having a predetermined release order; programming the computed transition altitude into each of the packages; releasing each of the packages in the predetermined order; comparing a pressure altitude to the transition altitude in the CPU of each package; jettisoning the drogue chute and deploying the main chute for each of the packages when the pressure altitude is less than or equal to the transition altitude; and descending each of the packages under its main chute, wherein the wind field affects the flight of some of the packages more than others based on the selection of the transition altitude for each package.

Abstract: Various embodiments are disclosed of a device for use on an unmanned aerial vehicle (drone) including two or more gimbals, a gimbal processor, an inertial measurement unit, and a communication connection. The two or more gimbals are pivotally coupled to rotate orthogonally relative to each other. An inner gimbal of the two or more gimbals may support an inner platform for receiving components thereon. An outer gimbal of the two or more gimbals may be pivotally coupled to the drone. The gimbal processor is mounted on the inner platform, wherein the gimbal processor is configured to control pivotal movement of the two or more gimbals. The inertial measurement unit may be fixed relative to the inner platform and coupled to the gimbal processor. The communication connection may be coupled to the gimbal processor and configured to exchange signals with the drone for controlling operations.

Abstract: A safety function module for a vehicle is provided. The safety function module comprises a status determination unit which is configured to determine at least a position of the vehicle. Thereby, the safety function module is configured to be reversibly coupled with a signal interface of the vehicle and is further configured to execute a comparison of the determined position of the vehicle with a predeterminable position range and to transmit an activation signal for a safe state of the vehicle to the signal interface if the position of the vehicle departs from the predeterminable position range. As the safety function module is functionally separated from the remaining components of the vehicle, the extent of possible interdependencies of the safety functions with other components of the vehicle may be reduced or eliminated.

Abstract: An imager device disposed on a moving body captures first image data at a first time and second image data at a second, subsequent time. An inertial measurement unit (IMU) disposed on the moving body senses motion of the moving body between the first time and the second time. The first image data is registered to the second image data based on inertial measurement data corresponding to the sensed motion to produce first registered image data. In response to identifying that image features are common to both the first registered image data and the second image data, the first registered image data is registered to the second image data based on the identified common features to produce output registered image data. In response to determining that no image features are common to both the first registered image data and the second image data, the first registered image data is output.

Abstract: A system and method for controlling a swarm of UAVs that are stored on and released from an airborne platform, fly to and destroy a target, where the UAVs download target information from the airborne platform before being released therefrom, do not communicate with each other or the airborne platform while in flight, and do not depend of the presence of GPS. Each UAV includes a vision sensor that provides image data, a navigation module that receives the image data and causes the UAV to navigate and fly towards the target, and a target destruction module that receives the image data and causes the UAV to destroy the target.

Abstract: A counter-flying object system comprising a sensor array including at least one active sensor configured to detect and track the flying object, and a missile launcher configured to launch an interceptor to intercept the flying object, wherein upon launching of the interceptor, the sensor array is configured to determine the location of the interceptor and send said object and interceptor locations to a control system, the control system being configured to provide mission data to the interceptor based on said object and interceptor locations for guiding the interceptor toward the flying object and activating a fragmentation warhead on or in the vicinity of said flying object when a lethality criteria is met.

Abstract: A drone launch system includes a canister defining an internal cavity, and a drone positioned within the internal cavity in a stowed state. The drone is configured to be ejected from the canister and transition from the stowed state into a deployed state outside of the canister. A method for launching a drone, the method includes positioning the drone in a stowed state in an internal cavity of a canister, ejecting the drone from the canister, and transitioning the drone into a deployed state after the ejecting operation.

Abstract: In some examples, a first entity is configured to request weather data for a region of interest from a second entity. The second entity may transmit the requested weather data to the first entity in response to receiving the request. In some examples, the second entity only transmits the weather data to the first entity only in response to receiving a specific request for the weather data. Conversely, the first entity may only receive the weather data from the second entity in response to transmitting a request for the weather data.

Abstract: A device receives a request for a flight path for a UAV to travel from a location to an anticipated location associated with a mobile device, and determines capability information for the UAV based on component information associated with the UAV. The device receives information associated with a current location, a direction of travel, and a speed of the mobile device, and calculates the flight path from the location to the anticipated location associated with the mobile device based on the capability information and based on the information associated with the current location, the direction of travel, and the speed of the mobile device. The device generates flight path instructions for the flight path, and provides the flight path instructions to the UAV to permit the UAV to travel from the location to the anticipated location associated with the mobile device, based on the flight path instructions.

Abstract: Described embodiments include an electro-shock projectile, a system, and a method. The electro-shock projectile includes a recognition circuit configured to recognize a body portion of a target human authorized for administration of a selected electric shock by electro-shock projectiles. The projectile includes a conductive electrode tip configured to administer the selected electric shock to the recognized body portion of the target human, the electric shock selected to inhibit voluntary movement by the target human. The projectile includes a guidance circuit configured to generate instructions directing the electro-shock projectile along a flight path toward the recognized body portion of the target human. The projectile includes a flight controller configured to operate a directional control surface in response to the generated instructions.

Abstract: Various technologies pertaining to computing angle of arrival of radio signals are described. A system that is configured for computing the angle of arrival of a radio signal includes a cylindrical sheath wrapped around a cylindrical object, where the cylindrical sheath acts as a ground plane. The system further includes a plurality of antennas that are positioned about an exterior surface of the cylindrical sheath, and receivers respectively coupled to the antennas. The receivers output measurements pertaining to the radio signal. A processing circuit receives the measurements and computes the angle of arrival of the radio signal based upon the measurements.