Abstract: Calibrating an antenna includes receiving a signal sent from a reference located within a region. The signal has a polarization within an expected polarization range. Polarization value sets are established in accordance with the expected polarization range. Polarization ratios are generated from the plurality of polarization value sets. A minimum polarization ratio variance for the plurality of polarization ratios is established. A polarization value set corresponding to the minimum polarization ratio variance is identified. A calibration correction is determined in accordance with the identified polarization value set.

Abstract: An apparatus for and method of employing synthetic aperture radar (SAR) images to automatically classify a target comprising emitting and collecting SAR signals at a plurality of squint angles, forming a plurality of SAR images of the target from the collected signals, the plurality of SAR images substantially having tilt angle diversity, automatically classifying the target from each of the plurality of SAR images, and generating a most probable target classification from the classifications of the plurality of SAR images.

Abstract: The present invention relates to a method and system using dynamic beam forming for wireless communication signals in a wireless network. Base stations and/or UEs are provided with antenna systems having a range of beam forming selections. Relative base station and UE locations are one type of criteria used to make beam forming decisions.

Abstract: A radar detection process includes computing a derivative of an FFT output signal to detect an object within a specified detection zone. In one embodiment, a zero crossing in the second derivative of the FFT output signal indicates the presence of an object. The range of the object is determined as a function of the frequency at which the zero crossing occurs. Also described is a detection table containing indicators of the presence or absence of an object within a respective radar beam and processing cycle. At least two such indicators are combined in order to detect the presence of an object within the detection zone and with changing range gates in each of the antenna beams the coverage of the detection zone can be varied.

Abstract: Estimating an antenna pointing error includes receiving a signal sent from a reference located within a region. A polarization ratio is evaluated over the region. A minimum polarization ratio variance for the polarization ratio is established. A location corresponding to the minimum polarization ratio variance is identified. An antenna pointing error is estimated from the identified location.

Abstract: A method for main beam alignment verification includes providing data pertaining to one or more patterns associated with an antenna, measuring power levels of a signal acquired by the antenna, and comparing the measured power levels with the data to determine whether a direction of the signal is incident upon a main beam of the antenna.

Abstract: A radar mount direction alignment device to be used for aligning the transmit/receive direction of a radar device 2D mounted on a member on which a radar device is to be mounted, such as a vehicle 1. The radar mount direction alignment device has receiving sections b9, b10 for receiving a signal emitted from the radar device 2D, and transmission sections a9, a10 for transmitting a signal to the radar device 2D. The radar mount direction alignment device has the function of emitting, toward the radar device 2D, a signal which, upon receipt of a signal output from the radar device 2D, behaves as if having been received at and reflected from a position farther from the radar device 2D than a distance between the radar device 2D and the radar mount direction alignment device.

Abstract: An antenna assembly for use with a level measurement device for measuring the level of a material held in a container is provided. The antenna assembly includes an upper section for coupling to the level measurement device, and an antenna for transmitting energy pulses emitted by the level measurement device and receiving energy pulses reflected by the material in the container. A transducer module is disposed between the upper section and the antenna. A controller is operably connected to the transducer module, the transducer module being responsive to control signals of the controller for activating the transducer module such that the transducer module, when activated by the controller, vibrates the antenna to dislodge or remove material adhering to the antenna.

Abstract: In the on-vehicle radar apparatus of the present invention, the vertical scanning width of the radar beam is narrowed, before the horizontal scanning, thereby avoiding unnecessary data processing and improving the data processing efficiently. Further, the S/N ratio of the target detection signal is increased, thereby stabilizing the distance detection and its accuracy. The vertical scanning antenna is a single travelling wave excitation antenna (TWEA) constructed by a plurality of antenna elements. At the same time, the horizontal scanning antenna is a multi-channel antenna wherein a plurality of TWEAs is assigned to a plurality of horizontal directions. The horizontal scanning angle is arbitrarily widened by increasing the number of TWEAs.

Abstract: A radar system derives a correction for an actual boresight (311) of a radar monopulse antenna mounted on a moving platform from ? data and ? data generated with respect to an a priori known, calibrated boresight (309). The monopulse antenna (602) is coupled to a ground position measuring system (616) while acquiring data. The radar receiver acquires a ? and ? synthetic aperture map of the same radar scattering location with respect to the calibrated boresight. ? SAR data and the ? SAR data are motion compensated using the position and velocity supplied by the ground positioning system. A computer forms a ratio of the aligned ? pixels to the aligned ? pixels for each of a plurality of aligned ? pixels located near the calibrated boresight. The correction for the location of the actual boresight of the monopulse antenna is computed by an analysis of the ratio of aligned ? pixels and corresponding aligned ? pixels over the radar scattering location.

Abstract: A method for adjusting a detection axis of an object detection system, wherein a disk-shaped adjusting member is fixed to a reference plane on an outer face of a casing, wherein the rotational position of the adjusting member is adjusted. The adjusting member has first and second base surfaces, between which a wedge shape is formed. Rotating the adjusting member finely adjusts the angle of the second base surface relative to the reference plane of the casing thereby resulting in the direction of the second base surface coinciding with the direction of an object detection axis of a radar mechanism part fixed within the casing. The direction of the object detection axis can be adjusted in the horizontal direction by placing a level on the second base surface of the adjusting member and adjusting the mounting angle of the casing so the level indicates a horizontal direction.

Abstract: A radar device mounted to a vehicle includes a camera for obtaining images including the road surface in front of or behind the vehicle on which it is mounted, a sensor having for obtaining at least positional information on a target object of detection such as another vehicle in front or behind and a control unit for correcting the direction of the center axis of the sensor based on the image obtained by the camera. The control unit detects a line segment along a lane in which the vehicle is traveling, detects a vector indicative of the direction on a road-fixed coordinate system of the obtained line segment, and controls correction of horizontal and vertical directions of the center axis of the sensor so as to coincide with the direction of the detected vector.

Abstract: A radar apparatus comprises a signal transmitter device that transmits a signal, a scanner that two-dimensionally scans a target object using the signal transmitted from the signal transmitter device by engaging in longitudinal oscillation and lateral oscillation, a signal receiver device that receives a reflection signal of a signal transmitted via the scanner and a control device that controls a longitudinal oscillation signal and a lateral oscillation signal used to oscillate the scanner longitudinally and laterally in correspondence to the length of time over which a scanning observation is performed through a two-dimensional scan.

Abstract: A radar detection process includes computing a derivative of an FFT output signal to detect an object within a specified detection zone. In one embodiment, a zero crossing in the second derivative of the FFT output signal indicates the presence of an object. The range of the object is determined as a function of the frequency at which the zero crossing occurs. Also described is a detection table containing indicators of the presence or absence of an object within a respective radar beam and processing cycle. At least two such indicators are combined in order to detect the presence of an object within the detection zone and with changing range gates in each of the antenna beams the coverage of the detection zone can be varied.

Abstract: A radar system mounted in a reference vehicle can detect a distance and orientation of a preceding vehicle to thereby compute a relative position of a width center of the preceding vehicle. A curving radius of the reference vehicle is then detected for computing a relative rotation angle between a direction from the reference vehicle and a longitudinal direction of the preceding vehicle. Relationship between a relative rotation angle and a lateral bias of the relative position of the width center is previously prepared in a map. The computed relative rotation angle is applied on the map, so that the corresponding lateral bias is obtained to correct the computed relative position of the width center of the preceding vehicle. Thus, the width center of the preceding vehicle moving in an adjacent lane can be accurately estimated.

Abstract: Stableness in detecting the distance to a preceding vehicle by calculating the distance to the preceding vehicle using reflected waves of a radar beam scanned at a scanning angle that is adjusted based on lane markers extracted from a road image obtained by a camera.

Abstract: To realize a monopulse radar system wherein the velocity of a mobile body, distance between an obstacle and the mobile body and relative velocity can be detected and simultaneously, the direction of the obstacle can be detected, in a monopulse radar system wherein an azimuth is detected depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, an array antenna composed of plural antenna elements is used for each transmitting antenna and each receiving antenna, at least one of the transmitting antenna and the receiving antenna is provided with an antenna switch for switching an antenna beam shape to a short angle/long distance or a wide angle/short distance and a switch control device that controls the switching of the antenna switch is provided.

Abstract: A radar detection process includes computing a derivative of an FFT output signal to detect an object within a specified detection zone. In one embodiment, a zero crossing in the second derivative of the FFT output signal indicates the presence of an object. The range of the object is determined as a function of the frequency at which the zero crossing occurs. Also described is a detection table containing indicators of the presence or absence of an object within a respective radar beam and processing cycle. At least two such indicators are combined in order to detect the presence of an object within the detection zone and with changing range gates in each of the antenna beams the coverage of the detection zone can be varied.

Abstract: A PC card with a retractable antenna for use in interfacing between a communications device and a wireless network includes an interface card portion and an antenna portion, the interface card portion having a first end, and an opposite second end, the first end having an electrical interface compatible with the communications device, the second end having an opening for slidably receiving the antenna portion, the interface card portion being dimensioned to be inserted into the PC card slot of the communications device, the antenna portion being in electrical communication with the interface card portion and dimensioned to fit inside the interface card portion, the antenna portion being accessible through the opening in the interface card portion by a user, the antenna portion being configured to extend out of the cavity and retract into the cavity of the interface card portion such that when the antenna portion is retracted into the cavity the antenna portion is substantially contained inside the interface c

Abstract: Stableness in detecting the distance to a preceding vehicle by calculating the distance to the preceding vehicle using reflected waves of a radar beam scanned at a scanning angle that is adjusted based on lane markers extracted from a road image obtained by a camera.

Abstract: The present invention is directed to a system and method for Doppler track correlation for debris tracking in PCL radar applications. The disclosed embodiments describe the systems and methods used in the detection of debris pieces and the association of the Doppler signals from the debris pieces across multiple illumination channels. The present invention also provides computation of debris state vectors and the projection of trajectories to determine debris impact points.

Abstract: A pulse radar system capable of mapping multiple targets essentially simultaneously using a single radar antenna. By alternately transmitting radar pulses toward multiple targets positioned at different angles relative to the antenna and alternately receiving return signals from the multiple targets as the radar antenna is switched between multiple beam positions, a time-interleaved radar operation is achieved which enables multiples targets to be mapped, and thus tracked, at the same time. A different radio frequency is preferably employed for each target so as to avoid interference and ambiguous returns. Using the teachings of the present invention, between two and twenty radar maps, and possibly more, can be generated simultaneously in approximately the same amount of time required to map a single target using conventional systems of the prior art.

Abstract: A system and method for detecting a radar target of interest in the presence of radar jamming interference include a sub-array beamformer, a sum and difference beamformer, a weight calculator, a composite beamformer, and a monopulse ratio calculator. A plurality of sub-arrays is formed from antenna array element data. Respective sum and difference beams are formed for each of the plurality of sub-arrays. A single weight is formulated from the sum and difference beams, respectively. Composite sum beams are formed in accordance with the sum weights and the sum beams, and composite difference beams are formed in accordance with the difference weights and the difference beams. Composite beams are formed such that at least one null of each of the composite beams is steered toward an interference and a boresight gain of each of the composite beams is maintained.

Abstract: A pulse radar system capable of mapping multiple targets essentially simultaneously using a single radar antenna. By alternately transmitting radar pulses toward multiple targets positioned at different angles relative to the antenna and alternately receiving return signals from the multiple targets as the radar antenna is switched between multiple beam positions, a time-interleaved radar operation is achieved which enables multiples targets to be mapped, and thus tracked, at the same time. A different radio frequency is preferably employed for each target so as to avoid interference and ambiguous returns. Using the teachings of the present invention, between two and twenty radar maps, and possibly more, can be generated simultaneously in approximately the same amount of time required to map a single target using conventional systems of the prior art.

Abstract: A method for adjusting a detection axis of an object detection system, wherein a disk-shaped adjusting member is fixed to a reference plane on an outer face of a casing, wherein the rotational position of the adjusting member is adjusted. The adjusting member has first and second base surfaces, between which a wedge shape is formed. Rotating the adjusting member finely adjusts the angle of the second base surface relative to the reference plane of the casing, thereby resulting in the direction of the second base surface coinciding with the direction of an object detection axis of a radar mechanism part fixed within the casing. The direction of the object detection axis can be adjusted in the horizontal direction by placing a level on the second base surface of the adjusting member and adjusting the mounting angle of the casing so the level indicates a horizontal direction.

Abstract: A radar detection process includes computing a derivative of an FFT output signal to detect an object within a specified detection zone. In one embodiment, a zero crossing in the second derivative of the FFT output signal indicates the presence of an object. The range of the object is determined as a function of the frequency at which the zero crossing occurs. Also described is a detection table containing indicators of the presence or absence of an object within a respective radar beam and processing cycle. At least two such indicators are combined in order to detect the presence of an object within the detection zone and with changing range gates in each of the antenna beams the coverage of the detection zone can be varied.

Abstract: Correlating observations of objects in the sky to determine an orbit includes identifying an initially identified object, determining if the initially identified object will be identifiable again, and identifying a subsequently identified object. A determination is then made by comparing characteristics of the initially identified object with the subsequently identified object. If the object correlate to one another a path or orbit of the object can be determined using the characteristics of the initially identified object and the subsequently identified object.

Abstract: An antenna control system is connected to an antenna in order to control the position of the antenna. The system includes a motor connected to the antenna for adjusting the position or vertical tilt angle of the antenna. A driver is provided for operating the motor. A sensor is also provided to detect the position of the antenna. In addition, an antenna controller is connected to an antenna memory, the driver, and the sensor, for reading the detected position of the antenna and for controlling the driver to adjust the antenna's position. A main controller is connected to the antenna controller for sending commands to and reading data from the antenna controller. In this manner, the main controller can interface with any number of antennas at a base station and control the position or down-tilt of each antenna. According to one embodiment of the control system, a user interface is also provided for entering commands to and reading data from the main controller.

Abstract: An airborne radar antenna system for detecting a target in a volume includes a tethered aerostat and an antenna that is supported above ground by the aerostat. The aerostat-based antenna is used for transmitting and receiving a radar beam into the volume to detect the target. Additionally, the system includes a ground-based transmitter that generates a beacon signal which monitors the antenna configuration at the aerostat. A computer then evaluates the beacon signal to create an error signal which is used to maintain a predetermined configuration for the antenna. The system also includes mechanisms for orienting the radar beam along preselected beam paths between the antenna and the volume.

Abstract: A radar system and technique provide the capability to detect a target of interest and maintain the detection in the presence of multiple mainlobe and sidelobe jamming interference. The system and technique utilize digital beamforming to form sub-arrays for canceling jamming interference. Jamming is adaptively suppressed in the sub-arrays prior to using conventional deterministic methods to form the sum, &Sgr;, and difference, &Dgr;, beams for monopulse processing. The system and technique provide the ability to detect a target of interest, provide an undistorted monopulse ratio, m, and maintain target angle estimation, in the presence of multiple mainlobe and multiple sidelobe jammers.

Abstract: An airborne radar antenna system for detecting a target in a volume includes a tethered aerostat and an antenna that is supported above ground by the aerostat. The aerostat-based antenna is used for transmitting and receiving a radar beam into the volume to detect the target. Additionally, the system includes a ground-based transmitter that generates a beacon signal which monitors the antenna configuration at the aerostat. A computer then evaluates the beacon signal to create an error signal which is used to maintain a predetermined configuration for the antenna. The system also includes mechanisms for orienting the radar beam along preselected beam paths between the antenna and the volume.

Abstract: An imaging system and method. The invention provides an intra-pulse repetition interval (PRI) agile beam technique for enhanced resolution that can be used at aspect angles near the velocity vector of a host vehicle. It is particularly useful at small scan angles where beam sharpening array times become large. At these scan angles, the bandwidth of the clutter is narrower than at higher scan angles and allows large PRIs without degradation from Doppler ambiguities. In accordance with the present teachings, sequential illumination is performed within a PRI to multiple beam locations using an agile beam. The interleaving of beams reduces map formation times compared to conventional techniques using sequential arrays. The inventive system is adapted for use with an electronically scanned (e.g., synthetic aperture array radar) antenna.

Abstract: A radar apparatus is provided in which an antenna axis and vehicle axis can agree with each other even when the antenna face is covered with a cover. In an assembling process of the radar apparatus composed of a chassis, an antenna incorporated in the chassis and a cover attached to the chassis to cover the antenna, a correlative positional relation between an antenna axis of the antenna incorporated into the chassis and one portion of the chassis or bracket is detected, and the thus detected data is inscribed on a seal and the seal is stuck to the chassis or the data is stored in an internal memory, and the chassis into which the antenna is incorporated is covered with the cover, so that the radar apparatus is manufactured. When this radar apparatus is attached to a vehicle, the antenna axis can be adjusted parallel to the vehicle axis by utilizing data of a correlative positional relation between the antenna and one portion of the chassis or bracket.

Abstract: A radar system includes a detection-control circuit for transmitting and receiving the beam of a millimeter-wave signal for detecting a relative position and a relative speed to a target, and a scanning unit for scanning the direction of the beam over a predetermined range. The state of the scanning unit can be switched between a resting state wherein scanning is stopped and the beam is directed towards the center of the scanning range while the detection-control circuit continues detection control, and a scanning state wherein the direction of the beam is scanned over a predetermined range.

Abstract: A weather radar display system displays a beam indicator indicative of a radar beam. The beam indicator represents width of the radar beam as a function of range (distance from the radar beam source). The beam indicator allows a pilot to easily discern accuracy of detected weather conditions based on the beam width.

Abstract: The relative altitude of the center of a radar beam in relation to the aircraft's altitude at a plurality of distance ranges from the radar source is computed. A plurality of range rings representing the distance ranges are displayed. The computed relative altitude is displayed adjacent to each range ring displayed.

Abstract: A system and method for suppressing ground clutter in avionics weather radars which includes automatically making multiple scans, closely spaced in time and space, and comparing the returning signals to known ground return signals over known tilt angle variations.

Abstract: A method and system for pointing and stabilizing a device that needs to be pointed and stabilized with a desired direction, are disclosed, wherein current attitude measurement and attitude rate measurement of the device measured by an attitude producer, which includes an inertial measurement unit, and the desired direction information measured by a target coordinates producer are processed by a pointing controller to compute rotation commands to an actuator. An actuator rotates and stabilizes the device at the desired direction according to the rotation commands in the presence of disturbances and parametric uncertainties to account for the undesired vibration due to disturbances. A visual and voice device provide an operator with visualization and voice indication of the pointing and stabilization procedure of the device.

Abstract: A PC card with a retractable antenna for use in interfacing between a communications device and a wireless network includes an interface card portion and an antenna portion, the interface card portion having a first end, and an opposite second end, the first end having an electrical interface compatible with the communications device, the second end having an opening for slidably receiving the antenna portion, the interface card portion being dimensioned to be inserted into the PC card slot of the communications device, the antenna portion being in electrical communication with the interface card portion and dimensioned to fit inside the interface card portion, the antenna portion being accessible through the opening in the interface card portion by a user, the antenna portion being configured to extend out of the cavity and retract into the cavity of the interface card portion such that when the antenna portion is retracted into the cavity the antenna portion is substantially contained inside the interface c

Abstract: A method and system for pointing and stabilizing a device that needs to be pointed and stabilized with a desired direction, are disclosed, wherein current attitude measurement and attitude rate measurement of the device measured by an attitude producer, which includes an inertial measurement unit, and the desired direction information measured by a target coordinates producer are processed by a pointing controller to compute rotation commands to an actuator. An actuator rotates and stabilizes the device at the desired direction according to the rotation commands in the presence of disturbances and parametric uncertainties to account for the undesired vibration due to disturbances. A visual and voice device provide an operator with visualization and voice indication of the pointing and stabilization procedure of the device.

Abstract: An AC power source applies power to a primary coil that is provided in a fixed part. An AC current flowing through the primary coil induces electromotive force in a secondary coil that is provided in a movable part. The AC electromotive force induced in the secondary coil is converted by an AC/DC converter into DC power, which is input to a drive control section.

Abstract: The invention describes a device and a method for increasing the angular resolution in a radar system looking in the direction of motion and laterally thereto, wherein the doppler frequency shift of the transmitted signal is evaluated in order to increase the angular resolution. For this purpose, a plurality of adjacent, narrow regions are sampled sequentially by means of pencil-beam antenna characteristics during movement of the antennas. Relative to the total area, this is equivalent to illumination with a broad-beam antenna characteristic. The results from the simulation of this broad-beam illumination are combined with the results of the pencil-beam sampling processes in order to achieve an increase of the angular resolution of the antenna array.

Abstract: On an element-by-element basis, measure phases between signals at Port A to Port B of the antenna feed network to get a phase measurement angle that corresponds to an angular difference between outgoing radar signals and target echo return signals; apply a least squares fit equation to the angular distance to get a correction phase slope across the array, &dgr;0, and applying a phase slope correction of &dgr; to the phases of the transmitted signal.

Abstract: A method for determining the velocity of features such as wind. The method preferably includes producing sensor signals and projecting the sensor signals sequentially along lines lying on the surface of a cone. The sensor signals may be in the form of lidar, radar or sonar for example. As the sensor signals are transmitted, the signals contact objects and are backscattered. The backscattered sensor signals are received to determine the location of objects as they pass through the transmission path. The speed and direction the object is moving may be calculated using the backscattered data. The data may be plotted in a two dimensional array with a scan angle on one axis and a scan time on the other axis. The prominent curves that appear in the plot may be analyzed to determine the speed and direction the object is traveling.

Abstract: A wideband adaptive digital beamforming technique for maintaining a high range resolution profile of a target in motion in the presence of jamming utilizes a sequence of adaptively calculated narrowband jamming cancellation weights. The adaptive weights are calculated such that the desired frequency dependent gain is maintained toward the target center. These adaptive weights tend to preserve the range profile quality and low range sidelobes. This technique also tends to eliminate signal cancellation problems as well as adaptive weight modulation effects.

Abstract: A PC card with a retractable antenna for use in interfacing between a communications device and a wireless network includes an interface card portion and an antenna portion, the interface card portion having a first end, and an opposite second end, the first end having an electrical interface compatible with the communications device, the second end having an opening for slidably receiving the antenna portion, the interface card portion being dimensioned to be inserted into the PC card slot of the communications device, the antenna portion being in electrical communication with the interface card portion and dimensioned to fit inside the interface card portion, the antenna portion being accessible through the opening in the interface card portion by a user, the antenna portion being configured to extend out of the cavity and retract into the cavity of the interface card portion such that when the antenna portion is retracted into the cavity the antenna portion is substantially contained inside the interface c

Abstract: A system and method for changing the phase relationship of input signals so as to generate a composite signal having the strongest possible signal. One related input vector signal is phase rotated and a phase is selected which yields the smallest value of the output composite signal. The selected phase is rotated 180 degrees. This procedure for that input signal is repeated for each input vector signal. When all inputs have thus been adjusted, the procedure can be repeated until the output composite signal is essentially free of errors.

Abstract: A radar system includes a detection-control circuit for transmitting and receiving the beam of a millimeter-wave signal for detecting a relative position and a relative speed to a target, and a scanning unit for scanning the direction of the beam over a predetermined range. The state of the scanning unit can be switched between a resting state wherein scanning is stopped and the beam is directed towards the center of the scanning range while the detection-control circuit continues detection control, and a scanning state wherein the direction of the beam is scanned over a predetermined range.

Abstract: A method for accurately tracking and communicating with a satellite from a mobile platform, wherein the satellite has an antenna which performs both transmit and receive functions from a single antenna aperture. The method involves using an inertial reference unit (IRU) of the mobile platform to initially acquire the signal from the satellite. A sequential lobing process is then used to more accurately center the antenna aperture relative to the receive beam from the satellite. The antenna is then used to transmit data or other information, and the antenna pointing is maintained by an additional IRU local to the antenna with higher accuracy and lower latency than the IRU of the mobile platform. Periodically, transmissions from the antenna are inhibited and the sequential lobing process is repeated to eliminate for any inertial reference drift error.

Abstract: A method for accurately tracking and communicating with a satellite from a mobile platform, wherein the satellite has an antenna which performs both transmit and receive functions from a single antenna aperture. The method involves using an inertial reference unit (IRU) of the mobile platform to initially acquire the signal from the satellite. A sequential lobing process is then used to more accurately center the antenna aperture relative to the receive beam from the satellite. The antenna is then used to transmit data or other information, and the antenna pointing is maintained by an additional IRU local to the antenna with higher accuracy and lower latency than the IRU of the mobile platform. Periodically, transmissions from the antenna are inhibited and the sequential lobing process is repeated to eliminate for any inertial reference drift error.