Abstract: A system and method for highly selective intrusion detection using a sparse array of ultra wideband (UWB) radars. Two or more UWB radars are arranged in a sparse array around an area to be protected. Each UWB radar transmits ultra wideband pulses that illuminate the area to be protected. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the area to be protected. This image is used to detect motion in a highly selective manner and to track moving objects within the protected area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.

Abstract: A system and method for controlling a radar antenna are provided. The method includes generating a first single beam antenna pattern, generating a second single beam antenna pattern and transmitting the first and second single beam antenna patterns. The method further includes using phase detection to determine angular information for a detected object based on a phase difference of received signals.

Abstract: A radar device separates directions of a plurality of targets, obtained from combinations of antenna beams, with a high accuracy. The radar device includes: a direction calculating unit for calculating a primary direction, which is the direction of a target, from a combination of characterizing quantities calculated by a signal detector from the reception waves of at least two beams that partially overlap, among the beams radiated in the plurality of directions; and a direction integrating unit for, when a plurality of primary directions calculated by the direction calculating unit is present, calculating an integrated direction, which is the true target direction, from an area in which distribution of the plurality of primary directions is a predetermined density or greater, based on the primary directions belonging to the area.

Abstract: The present invention relates to a method and an apparatus for determining whether a moving entity is moving in a predetermined direction. A moving entity being equipped with positioning means receives data from a sender comprising information about a position of a point of interest and a position of a reference point. Based on the received data, a first position of the moving entity at a first point in time, and a second position of the moving entity at a second point in time, it is determined whether the moving entity is moving in the predetermined direction. Preferably, angular information is utilized to verify whether the moving entity is moving in the predetermined direction.

Abstract: A method for radar target detection and angle estimation in the presence of jamming includes the steps of receiving a signal from a radar array having elements arranged in rows and columns; performing deterministic row-based beamforming on the received signal to obtain row sum azimuth beams; performing deterministic column-based beamforming on the received signal to obtain column sum elevation beams; performing one-dimensional maximum likelihood estimation on the row sum azimuth beams to obtain an estimated target elevation angle and an adaptive array sum azimuth beam; performing one-dimensional maximum likelihood estimation on the column sum elevation beams to obtain an estimated target azimuth angle and an adaptive array sum elevation beam; and performing target detection based on the adaptive array sum azimuth beam and the adaptive array sum elevation beam.

Abstract: The present inventive concept for bistatic or monostatic radar utilization discloses a method and a system for unambiguous angle resolution of a sparse wide-band array antenna by utilizing an ultra wide-band signal, generally a wide-band noise signal which may be continuous bandwidth limited white or colored noise. The noise signal is typically generated and radiated by a transmitting antenna covering the entire reception range of a receiving sparse antenna array. An echo signal is received by the sparse receiving array containing n antenna elements, which are generally positioned with separation distances of several wavelengths without creating strong grating lobes due to the type of generated transmit signal.

Abstract: An object is to implement transmission by an appropriate transmission method according to a type of information even in application of directional beam transmission.

Abstract: A vehicle-installed direction detection apparatus is controlled in accordance with the vehicle speed, to detect respective directions of one or more target objects by selectively applying high-resolution detection processing or low-resolution detection processing to received signals obtained from the elements of an array antenna of a radar apparatus, with the selection being determined in accordance with whether the speed attains a predetermined threshold value. The high-resolution detection processing is based on correlation between the received signals, utilizing an null scan type of algorithm such as MUSIC, while the low-resolution detection processing is based for example on digital beam forming.

Abstract: A wireless access point and method of deploying is disclosed including a radio component for wirelessly communicating with at least one mobile client and a connection from the access point to a network. A directional orientation component is provided for obtaining the directional orientation of the access point with respect to a predetermined coordinate system. The predetermined coordinate system can be a local coordinate system of a predetermined bounded area or with respect to the directional vectors relative to Earth's coordinate system.

Abstract: There is described an apparatus which monitors the orientation of or the rotational movement of a substantially spherical body. The apparatus comprises a substantially spherical body with at least one resonant circuit fixed thereto. A transmit aerial generates an alternating magnetic field in the region of space including the spherical body which induces an electric signal in the or each resonant circuit, and a receive aerial receives an induced sense signal generated in response to said induced electric signal in the or each resonant circuit. The electromagnetic coupling between the transmit aerial and the receive aerial via the or each resonant circuit varies in accordance with the orientation of the spherical body so that the induced sense signal in the receive aerial varies in accordance with the orientation of the spherical body.

Abstract: The disclosed system and method for determining direction-of-arrival generally includes an antenna element and a processor. The antenna element may configured to generate a signal in response to an electromagnetic wave. The processor may be process the signal to determine the direction-of-arrival of the electromagnetic wave. Further, the direction-of-arrival may be determined based on an estimate of the direction-of-arrival of at least one of the electric field and the magnetic field of the electromagnetic wave.

Abstract: A method and apparatus is operative for multiple target detection in a radar system which employs a radar waveform of two or more frequency diverse subpulses. The apparatus adds coherent processing of the subpulse echo signals to determine the presence of multiple scattering centers within the radar resolution cell. The subpulses are coherently combined and one can then estimate the number of scattering centers by forming a sample covariance matrix between the subpulse frequency channels and then performing an Eigenvalue decomposition. The resulting Eigenvalues represent the signal strengths of the scattering centers when the associated Eigenvectors correspond to the optimal subpulse weights associated with that signal. A single strong Eigenvalue indicates a single target while two or more strong Eigenvalues or those Eigenvalues larger than the noise related Eigenvalues or a threshold, indicates the presence of multiple targets.

Abstract: A vehicle-installed direction detection apparatus is controlled in accordance with the vehicle speed, to detect respective directions of one or more target objects by selectively applying high-resolution detection processing or low-resolution detection processing to received signals obtained from the elements of an array antenna of a radar apparatus, with the selection being determined in accordance with whether the speed attains a predetermined threshold value. The high-resolution detection processing is based on correlation between the received signals, utilizing an null scan type of algorithm such as MUSIC, while the low-resolution detection processing is based for example on digital beam forming.

Abstract: The frequency modulation radar device includes a transmitting unit (5), M receiving units for receiving a reflected signal as M channels, a mixing unit (7) for mixing the transmitting signal with the M received signals to obtain beat signals for the M channels, a frequency analyzing unit (9) for analyzing the beat signals for the M channels in frequency, and a calculating unit (1) for calculating a distance to a target object and an orientation angle based on frequency analysis results. The calculating unit (1) calculates a noise level from the frequency analysis result, extracts a peak signal of a subject target object in each of the channels based on the calculated noise level to generate a covariance matrix, discriminates between a signal eigenvalue and a noise eigenvalue among M eigenvalues of the covariance matrix, and estimates the number of incident signals based on the number of signal eigenvalues.

Abstract: An array antenna includes a first end portion that has a first plurality of antennas arranged with a spacing d therebetween and a second end portion that has a second plurality of antennas arranged with the spacing d therebetween. In the array antenna, a spacing between respective antennas in both the first and second end portions and are closest to a central portion is set to 2d, which is a value obtained from multiplying 2, which is the number of the antennas constituting each of both end portions, by the spacing d for both end portions. The antennas in the antenna array are continuously selected as a transmitting antenna by switching, and continuously emit transmission signals. The antennas in the antenna array are also successively selected as a receiving antenna by switching. In this way, by switching between transmission and reception of the antennas of the antenna array, nine reception channels CH1 through CH9 that are arranged with a uniform phase difference therebetween are obtained.

Abstract: A method to compensate for radar platform angular motion may include measuring or estimating any radar platform angular motion. The method may also include substantially decoupling each array subsection response of a plurality of array subsection responses from any radar platform angular motion by applying continuous time varying phase adjustments to each individual array subsection response, prior to forming composite array Sum and monopulse Delta beam responses The time varying phase adjustments may be determined in response to any radar platform angular motion measured or estimated.

Abstract: An apparatus for providing stabilization during a tracking operation may include a processing element configured to define an inertial pointing vector relative to a point of interest, receive tracking information related to the point of interest, and determine compensation of the inertial pointing vector based on the received tracking information and motion of a platform conducting the tracking operation.

Abstract: An apparatus for measuring at least one of unintentional and intentional electromagnetic emissions for at least one of enabling electromagnetic location of predetermined electronic equipment giving off such at least one of such unintentional and intentional electromagnetic emissions, tagging such predetermined electronic equipment and tracking such predetermined electronic equipment and various combination thereof. The apparatus comprises an emitter mechanism for providing an amplified electromagnetic energy which at least one of amplifies and changes a frequency content of the at least one of such unintentional and intentional electromagnetic emissions signature of a targeted electronic device by using an applied electromagnetic field generated by the emitter mechanism. There is a receiver for receiving the at least one of such unintentional and intentional electromagnetic emissions signature of such targeted electronic device.

Abstract: A radar apparatus can improve detection performance of a target, obtain high resolution without changing antenna construction, and suppress calculation load. A target detection unit, which calculates a distance, a relative speed, or a direction of the target based on frequency analysis results for a plurality of channels, includes a channel to channel integration unit that integrates, for each of the same frequencies, beat frequency spectra for the plurality of channels in the form of frequency analysis results for beat signals obtained for each of a plurality of receiving antennas, and a direction calculation unit that calculates the direction of the target from the beat frequency spectra for the plurality of channels.

Abstract: A signal incoming direction estimation apparatus is constructed so as to comprise a sensor array having plural sensors and the impedance of each of the sensors being set to a predetermined value, respectively, and a variable impedance adjustment means having a variable impedance, being selectively connected to any one of the sensors of the sensor array, and controlling the current distribution of each of the above-mentioned sensors. Due to this, it becomes possible for the signal incoming direction estimation apparatus to carry out a beam scan only by manipulating at least one impedance without simultaneously manipulating all of the sensor impedances and thereby a high-speed beam scan (directional control) becomes possible.

Abstract: A sampled beat signal is cut out into two or more short time data in a time direction concerning each antenna component. From a frequency spectrum of the short time data, an interference element frequency of an interference wave is detected. From the interference element frequency of the interference wave, two or more candidates of the frequency before aliasing of the interference wave are produced, and phase correction is executed on each candidate. Digital Beamforming is executed on the corrected frequency so as to extract maximum peaks of the power of an azimuth direction, and the frequency candidate showing the maximum peak power is selected and the arrival azimuth of the interference element is estimated. A filter for suppressing the interference element is applied on the short time data from the estimated arrival azimuth of the interference element so as to suppress the interference element.

Abstract: A radar apparatus includes a receiving means that receives a reflected signal, a beat signal generation means that generates beat signals based on the reflected signal, a correlation matrix generation means that calculates correlation matrices based on the beat signals, a storing means that stores previous correlation matrices, an addition means that calculates addition correlation matrices by adding the correlation matrices to the previous correlation matrices, a detection means that detects a frequency component satisfying a predetermined condition by using the beat signals, an extraction means that extracts an extraction matrix corresponding to the detected frequency from the addition correlation matrices, and a direction calculation means that calculates a direction of the object with respect to the radar apparatus based on the extraction matrix.

Abstract: In an in-vehicle mount radar device which has a reception antenna array containing plural reception antennas and two transmission antennas and in which a transmission pulse is time-divisionally and alternately transmitted from each of the two transmission antennas, a reception pulse based on the transmission pulse reflected from a target is received by each of the reception antennas, and at least angle information concerning the target is calculated by using reception data obtained by each reception antenna, the reception antenna array is constructed by arranging the plural reception antennas so that the reception antennas are spaced from one another at an interval d, each of the two transmission antennas is disposed so as to be spaced from the reception antenna located at each of both the end portions of the reception antenna array at an interval D, and the interval D is set to any value larger than the interval d.

Abstract: An boundary monitoring apparatus comprising an object detection device arranged to transmit a signal into a detection region and to detect an object in said detection region upon receipt of a reflected signal from said object; means for defining a boundary in said detection region; means for determining a path of said object in the detection region; means for performing an evaluation of the determined path of the object with respect to the boundary; and means for causing an alarm event depending on the evaluation.

Abstract: A radar apparatus is provided which includes a plurality of antennas arranged at unequally spaced intervals in a single row, the plurality of antennas configured to transmit a radio wave as transmitting antennas during continued multiple periods, and receive a reflected radio wave as receiving antennas during the continued multiple periods. A plurality of transceivers are included for transmitting a radio wave from the transmitting antennas and receiving received signals from the receiving antennas, said received signals representing the reflected wave received at the receiving antennas. A signal processing unit is included for selecting a transceiver which transmits a radio wave during each of the continue multiple periods, selecting transceivers which receive the received signals from the receiving antennas during each of the continued multiple periods, and perform digital beam forming with a first receiving signal channel group and a second receiving signal channel group.

Abstract: A radar signal processor has observation means for outputting a predetermined observation signal from a reflected wave, means for extracting an observation signal component concerning a target from the observation signal, means for computing a sample correlation matrix showing a correlation characteristic between the observation means from the observation signal components, means for estimating power of the reflected wave from the sample correlation matrix, and an array response matrix which is comprised of response vectors of the reflected waves. When estimating the power, an adjacent azimuth array response matrix having only the reflected waves of a predetermined arrival direction which power is to be estimated and the reflected waves of an azimuth adjacent to the reflected wave as elements is determined so as to estimate the power of the reflected wave.

Abstract: The present invention relates to a target tracking method of radar with frequency modulated continuous wave, which transmits a transmitted signal to receive a return wave of the transmitted signal that is used for detecting the target and obtaining the relative distance between the target and the radar. The target tracking method includes transmitting a frequency modulated continuous wave and receiving the reflected wave; getting a reflected wave corresponding to the target by detecting the reflected wave; getting a range gate error by seeking the plurality of the range gates corresponding to the reflected wave; and getting a position and a speed of the target at next time by knowing the position of the target at present time basis of the range gate error. Hence, the relative distance between the radar and the target is got.

Abstract: A transmitting apparatus and a receiving apparatus of a position detecting system execute a program including the steps of transmitting a laser beam; detecting an azimuth ?(Y) at which the laser beam is transmitted; detecting an azimuth ? at which the reflected laser beam is received; calculating a distance L(1) between the transmitting apparatus and a moving body from ?(Y), ? and a distance D between the transmitting apparatus and the receiving apparatus; and calculating a distance L(2) between the receiving apparatus and the moving body.

Abstract: A RADAR system including a set of RADAR apparatuses is disclosed. Each apparatus includes a processor, a pulse unit in signal communication with the processor, a waveform signal generator in signal communication with the pulse unit, and a set of radar antennas in signal communication with the waveform signal generator. The waveform signal generator is capable of generating a waveform signal in response to pulses provided by the pulse unit. The set of antennas is capable of transmitting a burst of microwave energy in response to each waveform signal and to receive a plurality of reflected bursts associated with the transmitted bursts. An acquisition unit is configured to develop and amplify a finite window integral associated with each reflected burst, the acquisition unit in signal communication with the set of antennas and a pre-processor configured to digitize and store information relating to each finite window integral for subsequent processing.

Abstract: An arrival angle estimation system includes a transmitting device and a receiving device and estimates an arrival angle at which frames transmitted by radio from the transmitting device arrive at the receiving device. The transmitting device includes two directional antennas each arranged so that its directivity is tilted at ±? degrees with respect to the front of the transmitting device. The receiving device includes a directional antenna having directivity toward the front of the receiving device. Frames are transmitted alternately from the respective directional antennas of the transmitting device, and received signal strengths of the frames on the receiving device side for the respective transmitting directional antennas are compared with each other to estimate the arrival angle.

Abstract: A target acquisition system. The novel system includes a housing, a first mechanism for obtaining position coordinates of the housing, a second mechanism for measuring a pointing angle from the housing toward a target, and a third mechanism for calculating coordinates of the target using the pointing angle and housing coordinates. The system may also include a fourth mechanism for determining a distance between the housing and the target, and a control circuit for receiving a user signal and in response thereto acquiring the housing coordinates, pointing angle, and distance data. The target coordinates may be calculated from the housing coordinates, pointing angle, and distance data, or from two or more sets of position coordinates and corresponding pointing angle data. The system may also include a transmitter for automatically transmitting the target coordinates to a remote weapons system or network.

Abstract: To obtain a radar system capable of obtaining an appropriate angular precision by calculating an angle error based on distributions of relative speeds and angles of reflecting points, and of obtaining the appropriate angular precision including an axis deviation angle by simultaneously calculating the angle error and the axis deviation angle. A radar system mounted on a movable body is provided with a radar device that calculates relative speeds and azimuth angles of plural reflecting points; an azimuth angle error estimating device that estimates an error of the azimuth angle calculated by the radar device based on the relative speeds and the azimuth angles of the plural reflecting points; and a correcting device that corrects the azimuth angle calculated by the radar device by using the azimuth angle error estimated by the azimuth angle error estimating device.

Abstract: A direction finding system used with an exit having a transmitter at that exit sending a location beam having a direction with respect to a compass direction. A receiver is carried by a person seeking directional guidance to the exit. The receiver receives the beam and determines the direction of the beam with respect to the compass direction. A display indicates the direction in which the person should move to reach the exit. Either the transmitter or the receiver or both may use an antenna array for sending and/or receiving a plurality of signals, each having a specific direction with respect to the compass direction. In a preferred embodiment, the receiver corrects for differences between the sent direction and the actual direction received.

Abstract: A radar apparatus includes a sending unit for sending a transmission wave, a plurality of receiving parts for receiving a reflected wave from a reflecting object in a parallel manner, beat signal generation parts for acquiring beat signals at the receiving parts, respectively, from the transmission wave and the wave received at the receiving parts, a beat signal processing part for individually processing the beat signals of the receiving parts, a DBF processing part for DBF processing a beat signal processing result, and an object detection part for acquiring information on the reflecting object from frequency components of a DBF processing result or the beat signal processing result. Amounts of phase lag of the receiving parts are set to different-values. The beat signal processing part includes a phase correction part that corrects the phase lag amounts corresponding to the individual receiving parts so as to make them equal to one another.

Abstract: A radar controlled automatic target illumination system for marine and other moving vessels. A radar system operably connected to the vessel produces an electronic signal corresponding to an azimuth of a target relative to, and in proximity to the vessel. An array of lights are connected to the vessel, each light being aimed outwardly in a different lighting sector, the sectors being adjacent one to another around the vessel, each of said lights, when automatically activated, illuminating one lighting sector. An electronic processor is operably connected between the radar system and the array of lights for the automatic selective activation of one or more of the lights to illuminate the target within a corresponding lighting sector which the radar system has identified.

Abstract: A direction detection apparatus transmits radar waves, with resultant reflected waves being received as incident waves by elements of an array antenna. Normally the direction of a target object is calculated based on analyzing respective received signals from the antenna elements, in calculations utilizing an estimated total number of incident wave directions. In an antenna direction adjustment mode, an actual number of target objects, and hence actual number of incident wave directions, is utilized in place of the estimated value, thereby enabling direction detection information to be obtained which does not fluctuate with time, thus facilitating the adjustment.

Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.

Abstract: A method to compensate for variances in signal path delays for a plurality of radar return processing channels is described. The method comprises providing a signal in the signal path between an antenna and a corresponding receiver of each radar return processing channel, receiving a reflection of the provided signal from each antenna at the corresponding receiver, measuring phase variances between the reflected signals processed by each receiver, and adjusting compensation algorithms for each radar return processing channel based on the measured phase variances.

Abstract: A scanning method of an in-vehicle scanning-type radar for emitting beams subsequently to execute scanning and for detecting an object includes determining whether or not the object is in an approaching state. When it is determined that the object is not in the approaching state, executed is a first scanning for scanning within a first angle range. When it is determined that the object is in the approaching state, executed is a second scanning for scanning within a second angle range that is narrower than the first angle. A period during which the radar scans the second angle range once in the second scanning is shorter than that during which the radar scans the first angle range once in the first scanning.

Abstract: A radar controlled automatic target illumination system for marine and other moving vessels. A radar system operably connected to the vessel produces an electronic signal corresponding to an azimuth of a target relative to, and in proximity to the vessel. An array of lights are connected to the vessel, each light being aimed outwardly in a different lighting sector, the sectors being adjacent one to another around the vessel, each of said lights, when automatically activated, illuminating one lighting sector. An electronic processor is operably connected between the radar system and the array of lights for the automatic selective activation of one or more of the lights to illuminate the target within a corresponding lighting sector which the radar system has identified.

Abstract: An arriving direction estimating device for estimating the arriving direction of an arriving wave with high accuracy and at high speed by using a sensor array. The arriving direction estimating device comprises a receiving section for generating a baseband signal from the arriving signals received by sensors, a matrix creating section for creating a spatial average covariance matrix R by combining the correlation vector of the baseband signal, a projection matrix creating section for creating a projection matrix Q from the matrix R depending on the number of signals of the arriving signals, a scale matrix creating section for creating a scale matrix S from a partial matrix of the matrix R, and an estimating section for estimating the arriving direction of the arriving wave from the angle distribution or an algebraic equation by using QS?1QH defined using the projection matrix Q and the scale matrix S.

Abstract: An in-vehicle radar apparatus includes a beam emitting part that emits a beam, a casing that supports the beam emitting part, and a reference unit that is attached to the casing and is equipped with multiple surfaces usable as a reference plane. A surface of the casing to which the reference unit is attached and the reference plane form an angle that depends on which one of the multiple surfaces is used as the reference plane.

Abstract: A system and method for highly selective intrusion detection using a sparse array of time modulated ultra wideband (TM-UWB) radars. Two or more TM-UWB radars are arranged in a sparse array around the perimeter of a building. Each TM-UWB radar transmits ultra wideband pulses that illuminate the building and the surrounding area. Signal return data is processed to determine, among other things, whether an alarm condition has been triggered. High resolution radar images are formed that give an accurate picture of the inside of the building and the surrounding area. This image is used to detect motion in a highly selective manner and to track moving objects within the building and the surrounding area. Motion can be distinguished based on criteria appropriate to the environment in which the intrusion detection system operates.

Abstract: The present invention is directed towards a ballistic missile detection and defense system. The system of the present invention comprises a ship based interceptor or antiballistic missile, a missile launch detection and tracking system, and a signal processing system capable of receiving said tracking signal calculating an intercept trajectory for an antiballistic missile to intercept a ballistic missile, and further capable of outputting an intercept trajectory program to an antiballistic missile.

Abstract: A method for determining an angle for each of two RF signals at different frequencies and offset from each other. The average angle of a composite signal is obtained from the two RF signals over a frequency difference period by averaging the frequency difference period. The average angle of the composite signal is the dominant signal's angle. The smaller signal's angle is then calculated from the dominant signal's angle, an angle centroid, and the signal voltages for the two RF signals.

Abstract: A system for tracking an object in space for position, comprises a transponder device connectable to the object. The transponder device has one or several transponder aerial(s) and a transponder circuit connected to the transponder aerial for receiving an RF signal through the transponder aerial. The transponder device adds a known delay to the RF signal thereby producing an RF response for transmitting through the transponder aerial. A transmitter is connected to a first aerial for transmitting the RF signal through a first aerial. A receiver is connected to the first, a second and third aerials for receiving the RF response of the transponder device therethrough. A position calculator is associated to the transmitter and the receiver for calculating a position of the object as a function of the known delay and the time period between the emission of the RF signal and the reception of the RF response from the first, second and third aerials. A method is also provided.

Abstract: A method for determining an angle for each of two RF signals at different frequencies and offset from each other. The average angle of a composite signal is obtained from the two RF signals over a frequency difference period by averaging the frequency difference period. The average angle of the composite signal is the dominant signal's angle. The smaller signal's angle is then calculated from the dominant signal's angle, an angle centroid, and the signal voltages for the two RF signals.

Abstract: The present invention provides a ball measuring apparatus capable of measuring a trajectory of a ball from a hitting position to a landing position, the landing position and a stop position. A ball measuring apparatus 100 according to a first embodiment includes a first millimeter wave radar device 1 capable of carrying out a measurement from the hitting position to a predetermined position of the trajectory and having at least one transmitting antenna and a plurality of receiving antennas, and a second millimeter wave radar device 2 capable of measuring the stop position and having at least one transmitting antenna and a plurality of receiving antennas. A ball measuring apparatus 101 according to a second embodiment has a millimeter wave radar device 31 and a CCD camera 32.

Abstract: A method for determining a mechanical angle to a radar target utilizing a multiple antenna radar altimeter is described. The method comprises receiving radar return signals at the multiple antennas, populating an ambiguity resolution matrix with the electrical phase angle computations, selecting a mechanical angle from the ambiguity resolution matrix that results in a least amount of variance from the electrical phase angle computations, and using at least one other variance calculation to determine a quality associated with the selected mechanical angle.

Abstract: The present invention relates to a radar apparatus that forms multiple digital beams based on reflected waves of a transmitted radio wave. A transmit signal is transmitted in a predetermined cycle from one of transmitting/receiving antennas A1 to A4 arrayed in a row. The antennas A1 to A4, each switched between transmission and reception, are arranged such that the ratio of the spacing between one pair of adjacent antennas to the spacing between the other pair of adjacent antennas is 1:2. The reflected waves are received by the respective antennas, and DBF is performed based on the resulting received signals. Eleven-channel DBF is achieved using the four antennas with a space equivalent to six antennas. By achieving multiple channels with a minimum number of antennas, the size and cost of the apparatus can be reduced while also reducing the processing time and thus enhancing the performance.