Abstract: A maximum gap method and system provide for identifying a space sector within which a system capable of engaging an object, should search for the object. A detector system that may be a radar or other active range determination system tracks position of the moving object and based on position estimates and the uncertainties associated with the position estimates, generates a range of possible positions for each estimate then determines gaps between the uncertainties and derives the search sector based on the maximum gap.

Abstract: In a radar with a non-uniformly spaced antenna array, an extractor estimates a number of arrivals of echoes to the antenna array. A setter sets a number of azimuths corresponding to a number of extracted peaks as a number of tested azimuths greater than the number of arrivals of echoes by a preset number. A determiner determines a level of correlations among steering vectors respectively corresponding to the tested azimuths. A selector selects, from the tested azimuths, azimuths as power-estimation targets based on the determined level of the correlations among the steering vectors. A first estimator estimates a received power level from each power-estimation target. A second estimator estimates, from the power-estimation targets, an azimuth of the target based on the estimated received power level from each power-estimation target. The estimated received power level from the azimuth is equal to or greater than a preset threshold level.

Abstract: A method detects a target in a radar signal using space-time adaptive processing. A test statistic is T = max ? ? max ? ? ? R ? f 1 ? ( x 0 , x 1 , … ? , x K ? ? , ? , R ) ? p ? ( R ) ? ? ? R max ? ? ? R ? f 0 ? ( x 0 , x 1 , … ? , x K ? ? , R ) ? p ? ( R ) ? ? ? R , where x0 is a test signal, xk are K training signals, ? is an unknown amplitude of a target signal within the test signal, ? is a scaling factor, R is a covariance matrix of the training signals, and a function max returns a maximum values. The test statistic is compared to a threshold to determine whether the target is present, or not.

Abstract: A High Performance Unattended Ground Sensor (HiPer-UGS) system and methods comprising low-power fully functional and independent radar-nodes that communicate directly with a remote radar information gathering or relay point using a long distance communications transceiver co-located in the radar-node.

Abstract: A radar volume in a cued direction is searched with sequential pencil beams. The allowable scan time is limited. The cued direction and uncertainty identify a search face, and the range gives a search volume. The number of beams required to scan the volume is determined, and compared with the maximum time. If less than the maximum, the scan is initiated. If greater than the maximum time, the scan region about the cued volume is subdivided into smaller portions, each of which is scanned sequentially.

Abstract: A route data base generating system avoids GPS satellite signals sources for land based vehicle azimuth and heading determinations in areas where reception of the satellite signals is unavailable or impaired and relies on vehicle part movements that are equatable to the heading and azimuth changes of the vehicle for determining such vehicle orientations. Part movements equatable to the heading changes are found in the vehicle wheel assemblies. A route data base founded on interconnecting linear route segments that are arranged in and end-to-end serial order is advocated and wherein the angular deviation between connecting segments in the order is predetermined. Various uses of the generating systems and related procedures are advocated for both on-the-road and off-road usage.

Abstract: To provide a target detection system including transmitters/receivers constituted with radars, sonars, or lidars, which is capable of effectively capturing a target even under an environment where the S/N ratio is low and reflected signals may be buried under noises. The target detection system is characterized to include at least two target-detecting transmitters/receivers capable of performing azimuth setting placed at different placing positions from each other; and a main control device including a position calculating module which specifies a position of a target based on reflection information regarding the azimuth of the target detected by each of the transmitters/receivers, wherein the position calculating module includes a function which specifies the position of the target through performing superimposing processing of information regarding the azimuth of the target acquired by the two transmitters/receivers on the basis of positional information of each of the transmitters/receivers.

Abstract: A signal wave arrival angle measuring device includes: an observation data vector generation section generating an observation data vector necessary for an angle measurement of a signal wave from an electrical signal having been converted at a sensor group converting the signal wave of an observation target to the electrical signal; an ESPRIT angle measurement processing section calculating an arrival angle of the signal wave from the generated observation data vector; an arriving signal wave estimation section estimating information other than the arrival angle of the arriving signal wave from an angle measurement processing process data of the ESPRIT angle measurement processing at the ESPRIT angle measurement processing section; and a reliability determination section determining whether or not an angle measurement result of the calculated arrival angle is correct based on an estimation result of the arriving signal wave estimation section, and excluding an erroneous angle measurement result.

Abstract: A method and a system for sensing a boosting target missile, estimate position and velocity and boost acceleration parameters of the target missile, and control an interceptor missile to the target missile. A boost-phase missile target state estimator estimates at least acceleration, velocity, and position using an acceleration template for the target vehicle. The nominal template is incorporated into an extended Kalman filter which corrects the nominal template acceleration with the filter states to predict future thrust acceleration, velocity and position. The correction can compensate for motor burn variations and missile energy management (lofted/depressed trajectory).

Abstract: A passive tracking system is provided with a plurality of ultrawideband (UWB) receivers that is asynchronous with respect to a UWB transmitter. A geometry of the tracking system may utilize a plurality of clusters with each cluster comprising a plurality of antennas. Time Difference of Arrival (TDOA) may be determined for the antennas in each cluster and utilized to determine Angle of Arrival (AOA) based on a far field assumption regarding the geometry. Parallel software communication sockets may be established with each of the plurality of UWB receivers. Transfer of waveform data may be processed by alternately receiving packets of waveform data from each UWB receiver. Cross Correlation Peak Detection (CCPD) is utilized to estimate TDOA information to reduce errors in a noisy, multipath environment.

Abstract: A passive system is described for detecting radar emissions from vessels, receiving the radar emissions and analysing the data using a series of algorithms and software manipulation to extract radar signatures representative of the identity of the vessel. The data output is capable of comparison with a stored set of data enabling accurate identification of the vessel. The resulting output is displayed on a suitable display. A system having a library of vessel emission signatures can either be created within the operator's library through measurement made, or it can be supplied from a central database. The system is capable of installation on sea, land or air-based platforms.

Abstract: A method for collision avoidance for a host vehicle includes the following steps; receiving input data relating to a set of objects external to the host vehicle, wherein an object position (r,?), and an object velocity ({dot over (r)}) are associated with each object by a sensor system arranged on the host vehicle, then estimating future trajectories of each external object, while considering influence by the future trajectories of the other external objects.

Abstract: A system and method for self and group location and tracking based on ultra wide band ranging among members of the group is presented. The system comprises an anchored station, a plurality of nodes, each node having at least knowledge of where the node is facing and heading, knowledge of all pair wise distances among all of the plurality of nodes, and ability to exchange information among the nodes and with the anchored station via relays. The system and method find a new position estimate of the group in accordance with an adaptive search process based on constraints of the ultra wide band ranging, and the search process enables extracting directional information and adaptively stabilizing orientation of the group. In one embodiment, adaptively stabilizing the orientation of the group is performed using an orientation-correcting polygon matching process.

Abstract: The present invention provides a radar apparatus capable of changing a characteristic of filter processing while considering also a relative velocity of an object. A measurement section measures a relative position and a relative velocity of an object such as another vehicle, a pedestrian, and an object placed on a road. The radar apparatus calculates a time until the object and an own vehicle collide with each other, based on the relative position and relative velocity of the object measured by the measurement section, and changes, based on the calculated time, a filter coefficient to be used when filter processing is performed on a measured position converted from the measured relative position of the object, thereby changing a characteristic of the filter processing to be performed on the measured position, between stability and responsiveness.

Abstract: Provided is a radar device capable of accurately calculating directions and the number of targets. A direction calculation unit includes a correlation matrix addition prohibition unit that prohibits, when a peak frequency in a plurality of modulation periods of a target is in the vicinity of 0, addition of a correlation matrix generated from a peak frequency spectrum having the peak frequency in the vicinity of 0, and calculates the direction of the target on the basis of a summed correlation matrix in which correlation matrices generated from peak frequency spectra having peak frequencies out of the vicinity of 0.

Abstract: There are provided method and system for deinterleaving signals. The method comprises: (a) recording plural signal reception events, wherein each signal reception event is associated with a received signal at a receiver, and represented by a space-time coordinate having a space component based on a location of the receiver and a time component based on an arrival time of the received signal; (b) selecting a subset of signal reception events from the recorded signal reception events, wherein the number of signal reception events in the subset is based on the dimension of the space component; and (c) determining whether the signal reception events in the selected subset satisfy a predetermined condition, and if the determination is in the affirmative, associating the signal reception events in the selected subset with an emission of an emitter.

Abstract: A method of determining a deviation of a path of a projectile from a predetermined path. The method uses an image of a target area in which the desired path or direction is pointed out. Subsequently, the real direction or path is determined and the deviation determined.

Abstract: In order to enhance a safety system, in particular an accident avoidance system for a means of transportation, in particular a motor vehicle, having at least one steering system and at least one brake system in such a way that an avoidance maneuver initiated by the operator of the means of transportation when approaching an obstacle is supported with respect to both the device and the method, thus preventing an accident through collision, the evaluation unit determines at least one driving variation, in particular at least one avoidance trajectory and/or at least one automatic emergency braking action from the data and information and when or after the operator of the means of transportation initiates a driving maneuver, in particular an avoidance maneuver or an emergency braking maneuver, the safety system, in particular the evaluation unit specifies, supports and/or suggests this driving maneuver in an optimized form, in particular in the form of an optimal avoidance trajectory or in the form of an automati

Abstract: In accordance with one of embodiments of the present invention, a frequency resolution processing unit calculates complex number data based on a beat signal caused by a receiving wave coming from a target and a transmission wave. A target detection unit detects a peak value from the intensities of beat frequencies, and then detects an existence of the target. The target link unit makes association between a target detected in the present detecting cycle and the target detected in the past detecting cycle. A direction estimating unit generates a generative complex number data based on the complex number data so as to correspond to a data generation unit. The direction estimating unit calculates, for each antenna, an incoming direction of the receiving wave based on each of normal equations formed by use of the complex number data of the beat frequency which an existence of the target is detected and the generative complex number data.

Abstract: A device for detecting an azimuth has a transmission array antenna having plural transmission antenna elements arrayed along an array axis and a receiving array antenna having plural receiving antenna elements arrayed along the array axis. A reception signal is acquired for each of channels by transmitting and receiving a search wave through each of the channels. The channels are arbitrary combinations of each of the transmission antenna elements and each of the receiving antenna elements. A first spatial frequency analysis is performed along the array axis of either ones of the transmission antenna elements and the receiving antenna elements using the reception signal. A second spatial frequency analysis is then performed along the array axis of the other ones of the antenna elements using results of the first spatial frequency analysis. An azimuth of a target is determined based on analysis results from the second spatial frequency analysis.

Abstract: A movement detection system includes a microwave antenna able to transmit microwave frequency signals into a space. An electronics controller is connected to the microwave antenna, and is configured to continually measure the impedance of the microwave antenna while it transmits microwave frequency signals into the space. An interpretive device is connected to receive impedance measurements from the electronics controller, and is configured to interpret and report changes in the magnitude and phase angles of individual impedance measurements as the passing of things and their direction through the space.

Abstract: A radar apparatus includes: an array antenna having antenna elements having function of a transmission antenna and a reception antenna and receiving an echo signal which is a reflection of a probe signal from a target, the probe signal being radiated from the antenna elements; a converter for converting the echo signal to a baseband signal; a signal synthesizing unit which generates a synthesized baseband signal vector on the basis of aperture synthesis of the baseband signal generated from a combination of the antenna elements giving an equal spatial phase; a correction data acquiring unit which acquires correction data on the basis of coefficients of terms of a synthesized array polynomial; a correction processing unit which corrects the synthesized baseband signal vector on the basis of the correction data; and an estimating unit which performs angle estimation on the basis of the synthesized baseband signal vector.

Abstract: A radar device has a plurality of receiving antennas which receive, as a reception wave, a radar wave sent in a predetermined reference direction and reflected by a target; a phase difference detection unit which detects a first phase difference of the reception wave received by a first receiving antenna pair that is spaced by a first gap, and a second phase difference of the reception wave received by a second receiving antenna pair that is spaced by a second gap smaller than the first gap; and an angle detection unit which performs a first process of determining, as a detection angle, an angle of the target relative to the reference direction being a mutually coincident angle from among a plurality of first angles corresponding to the first phase difference and a plurality of second angles corresponding to the second phase difference. The radar device allows expanding an angle detection range without reducing the resolution of the angle corresponding to the second phase difference.

Abstract: A radar apparatus has a plurality of receiving antennas and an array transmitting antenna controlled to successively vary the direction of a transmitted beam within a range which includes a target detection range of directions. The direction of any target within the target detection range is detected based on a phase difference between incident reflected waves of adjacent receiving antennas. To eliminate false targets resulting from aliasing, each detected target is authenticated based upon closeness of its detected direction to the current transmitted beam direction. The receiving antennas and transmitting antenna are configured to exclude directions of grating lobes of the transmitted beam from the detection range, and thereby suppress effects of received reflected waves that originate from grating lobes.

Abstract: A method of calculating the position or state of motion of one or more terminals is proposed in which each has a receiver capable of making measurements of signals received from one or more transmission sources for use in calculating the unknown position or state of motion of the or each terminal. At least one transmission source has a known directional transmission pattern, and the bearing from one of the receivers of the or each of the transmission source having a known directional transmission pattern is estimated. Weights are assigned to the measurements made by the one receiver, the weights being calculated from the bearing or bearings and the known directional transmission pattern of the transmission sources.

Abstract: A radio-frequency tag communication system including (a) a radio-frequency tag, (b) a radio-frequency tag communication device configured to transmit a transmitted signal toward the radio-frequency tag, and to receive a reply signal transmitted from the radio-frequency tag in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag, and (c) at least one reference tag disposed fixedly in an area of communication of the radio-frequency tag communication system and configured to transmit a reply signal in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag communication device, and wherein the radio-frequency tag communication device includes a directivity control portion configured to control a directivity of communication with the radio-frequency tag, on the basis of a result of the radio communication of the radio-frequency tag communication device with the at least one reference tag.

Abstract: Disclosed is a method, means for and computer program for enhancing range and azimuth resolution in a two-dimensional (2D) image generated by a frequency modulated continuous-wave (FMCW) radar for providing enhanced situational awareness in autonomous approach and landing guidance (AALG) system by forming and displaying a two-dimensional (2D) model of landing conditions from received range and azimuth real beam radar (RBR) signals by rendering one or more target locations and amplitudes in both range and azimuth, selecting a region of interest from the displayed 2D model to enhance the one or more target locations in the selected region of interest, selectively applying range and azimuth resolution enhancement using a first and second beamforming approach or applying azimuth only resolution enhancement by using just the second beamforming approach to obtain an one or more accurate target location estimations and combining the enhanced one or more target locations to render an enhanced 2D image.

Abstract: In an embodiment, a coordinate determiner is operable to identify at least first and second surfaces that each approximately intersect an object, and to determine at least two approximate coordinates of the object from the first and second surfaces, where at least one of the surfaces is nonplanar. For example, if the coordinate determiner is disposed on a fighter jet having at least to short-baseline-interferometers (SBIs), then two surfaces may be the surfaces of two cones having two of the SBIs as respective vertices, the object may be a close-in target, and the coordinate determiner may determine the azimuth and elevation of the target from the cone surfaces. Furthermore, the coordinate determiner or another computation unit onboard the jet may determine the slant range of the target from the elevation and the altitude of the jet.

Abstract: In a conventional automotive radar, a return occurs in a phase difference characteristic necessary for a super-resolution method, resulting in an increase of a detection error, or an extremely narrowed azimuth detection range. A transmitting array antenna, and receiving array antennas are composed of antenna elements respectively, and aligned in a horizontal direction. The weighting of receiving sensitivities of the antenna elements of the receiving array antenna 1 is A1, A2, A3, and A4, which are monotonically decreased from an inner side toward an outer side as represented by A1?A2?A3?A4. On the other hand, the receiving array antenna 3 is symmetrical with the receiving array antenna with respect to the receiving array antenna 1.

Abstract: A guidance system for actively guiding a projectile, such as a bullet after it has been fired from a gun. The guidance system includes a radar unit that includes a plurality of receiver arrays. An optical scope is also mounted to the gun for optically sighting a target. An inertial measurement unit provided on the gun locks onto the target after it has been sighted by the scope, and provides a reference location at the center of the receiver arrays from which the bullet can be directed. The receiver arrays receive radar monopulse beacon signals from the bullet. The signals from the bullet are used to identify the position of the bullet and the roll of the bullet. The signals sent to the bullet provide flight correction information that is processed on the bullet, and used to control actuators that move steering devices on the bullet.

Abstract: A system for estimating an antenna boresight direction. The novel system includes a first circuit for receiving a Doppler measurement and a line-of-sight direction measurement corresponding with the Doppler measurement, and a processor adapted to search for an estimated boresight direction that minimizes a Doppler error between the Doppler measurement and a calculated Doppler calculated from the estimated boresight direction and the line-of-sight direction measurement. The line-of-sight direction measurement is measured relative to the true antenna boresight, and the calculated Doppler is the Doppler calculated for a direction found by applying the line-of-sight direction measurement to the estimated boresight direction. In a preferred embodiment, the first circuit receives a Doppler measurement and a line-of-sight direction measurement from each of a plurality of pixels, and the processor searches for an estimated boresight direction that minimizes a sum of squares of Doppler errors for each of the pixels.

Abstract: An electronic scanning radar apparatus includes a transmission unit configured to transmit a transmission wave, and a receiving unit including a plurality of antennas receiving a receiving wave coming from a target. The receiving wave is formed from a reflection wave of the transmission wave reflected at the target. A beat signal generation unit is configured to generate beat signals in response to the transmission wave and the receiving wave. A frequency resolution processing unit is configured to obtain complex number data calculated from beat frequencies having signal levels obtained by performing a frequency resolution for the beat signals based on a predetermined frequency width. A peak detector is configured to detect an existence of the target by detecting peak signal levels of the beat frequencies, and a direction detecting unit is configured to calculate an incoming direction of the receiving wave based on a normal equation having an order.

Abstract: A radar system is disclosed, which comprises an orthogonal frequency division multiplexing (OFDM) modem and a frequency scanning antenna. In transmit, the OFDM modem modulates radar waveforms and the frequency scanning antenna radiates the OFDM modulated radio frequency (RF) energy. In receive mode, the frequency scanning antenna captures the echoes and the OFDM modem demodulates the echoes. Directionality of the frequency scanning antenna is dependent upon RF carrier frequency. In other features, the radar system further comprises a transmit/receive (T/R) module that up-converts and amplifies the OFDM modulation, and outputs the amplified signal to the frequency scanning antenna. The T/R module amplifies and down-converts a received RF echo from the frequency scanning antenna and outputs the down-converted echo to the OFDM modem. A plurality of scanning angles are measured simultaneously.

Abstract: Embodiments relate to radar systems and methods. In an embodiment, a system includes a radio frequency (RF) sensor array comprising a plurality of spaced apart sensors; and a reflector element positioned proximate the RF sensor array to reflect waves toward the RF sensor array. In an embodiment, a system includes an antenna array comprising a transceive antenna and a plurality of receive antennas; a mirror arranged proximate the antenna array; a voltage controlled oscillator (VCO) configured to generate a signal to be transmitted by the transceive antenna; and a controller configured to resolve signals received by the plurality of receive antennas to determine an angular position of a target, wherein the signals received include a first portion of the signal reflected by the target and a second portion of the signal reflected by the target and the mirror.

Abstract: A collision prediction system includes a collision face determining unit that determines a collision face of the own vehicle which is presumed to collide with another vehicle, based on a travelling direction of the other vehicle relative to the own vehicle at an estimated collision time at which a collision is presumed to occur, a collision position estimating unit that estimates a collision position as a position of a potential collision between the own vehicle and the other vehicle, based on the collision face determined by the collision face determining unit, and a collision position correcting unit that corrects the collision position estimated by the collision position estimating unit, based on a preset size of the other vehicle.

Abstract: This scanning array scans an area around the array for nearby objects, collision obstructions, and terrain topography. The scanning array can scan for sounds emitted by objects in the vicinity of the scanning array, passive energy receipt sources, or it can also send out an energy beam and scan for reflections from objects within the energy beam. The energy beam can be optical, laser, radar or other energy emitting sources. The scanning array of the invention can be used for helicopter detection and avoidance of collision risk and can be used for other scanning purposes. Scanning of an entire hemisphere or greater is accomplished by manipulating the scanner platform through the coordination of either linear actuators or gimbals so as to produce nutation without rotation. This motion allows transceivers to be directly coupled to transmitting and sensing modules without the losses associated with slip rings and other coupling devices.

Abstract: A radar apparatus, an antenna apparatus, and a data acquisition method are provided, which can reduce the size of a radar apparatus as well as maintaining angular resolution.

Abstract: A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveforms and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.

Abstract: The present invention relates to a handheld radar apparatus. The apparatus comprises an antenna (22,23) adapted to transmit and receive electromagnetic signals, a direction sensor (24, 25) that outputs an orientation signal indicative of the orientation of the antenna, and a radar (21) coupled to the antenna (22, 23), the radar (21) adapted to generate an electromagnetic signal for transmission via the antenna (22, 23), and adapted to receive a reflected version of the electromagnetic signal via the antenna (22, 23) reflected from an object. The radar (21) comprises a processor (30) for generating location information indicative of the location of the object using the received reflected electromagnetic signal and the orientation of the antenna (22,23) as indicated by the orientation signal, and a screen (4) adapted to display indicia (e.g. 43a to 43c) representing the object and its location based on the location information.

Abstract: An apparatus a transmitter section, a receiver section, and a processing module. The transmitter section transmits a plurality of high carrier frequency beamformed signals in a loop manner until a desired number of signals has been transmitted. The receiver section receives the plurality of high carrier frequency beamformed signals and determines reception properties of the plurality of high carrier frequency beamformed signals. The processing module determines at least one of: reflection, absorption, refraction, and pass through based on the reception properties. The processing module then distinguishes an animate entity from an inanimate entity based on the at least one of the reflection, absorption, refraction, and pass through. The processing module then determines position of the animate entity within a given physical area.

Abstract: A blockage detection system and method for use in a sensor such as a side object detection (SOD) sensor in an automotive radar system is described. The sensor emits signals and receives return signals (i.e. reflected signals) from a passing object. If the passing object is within a virtual detection zone, the sensor uses the information from the passing object to determine if a blockage condition exists in the sensor. The technique utilizes statistics related to the passing object to determine whether a blockage condition exists within the sensor. In one embodiment, a SOD sensor mounted in a first vehicle uses information from a second passing vehicle (e.g. radar return information) to determine whether a blockage condition exists within the SOD sensor itself.

Abstract: A detector apparatus, detection system, and method are provided for determining optimum operational angles based on the statistical correlation of wavelength-specific electromagnetic propagation and surface interaction. These techniques can be used within the radar community in both military and commercial radar applications for airborne radar system users to determine optimum operational depression angles based on the purpose of the effort, the operational frequency, and the terrain-type to be encountered. The method requires the user to interface with a standard computer equipped with the commercially available MATLAB® software package where the operation is presented as a graphic user interface (GUI) that once invoked allows the user to set specific parameters corresponding to the desired terrain type. Upon doing so, the algorithms are exercised and the results are displayed in a series of figures identifying the optimum operational angles.

Abstract: The present invention relates to a method for angular determination and/or for increasing the angular resolution or a detectable angular range when operating antenna groups using the technique of digital beam forming (DBF), as well as a device for carrying out the method. In the method, a measurement signal with a carrier signal and a frequency-modulated signal component are received via at least one antenna group directly or after reflection on one or several objects. The angle, at which the measurement signal is received, is determined by evaluating a phase difference in the received measurement signal which occurs between adjacent antenna elements of the antenna group. The method is characterized in that for determining the phase difference the frequency-modulated signal component is also evaluated, exclusively or additionally to an evaluation of the carrier signal.

Abstract: A system for classifying targets utilizes radar receptions and acoustic signatures of armament projectiles (e.g., bullets from celebratory rifle fire, mortars, cannon fire, artillery shells, or rockets, etc.) to associate ordinances with radar returns to better utilize a radar's resources to acquire and track targets of interest. In one embodiment of the invention the system for classifying targets comprises: a radar system for detecting targets based upon radar receptions; an acoustic system for detecting targets based upon acoustic receptions; and a means for classifying the acoustic receptions into target types; a means for computing range, bearing and time of incidence for the radar receptions and the acoustic receptions; a means for associating the radar receptions and the acoustic receptions according to the classification.

Abstract: Narrow virtual transmit pulses are synthesized by differencing long-duration, staggered pulse repetition interval (PRI) transmit pulses. PRI is staggered at an intermediate frequency IF. Echoes from virtual pulses form IF-modulated interference patterns with a reference wave. Samples of interference patterns are IF-filtered to produce high spatial resolution holographic data. PRI stagger can be very small, e.g., 1-ns, to produce a 1-ns virtual pulse from very long, staggered transmit pulses. Occupied Bandwidth (OBW) can be less than 10 MHz due to long RF pulses needed for holography, while spatial resolution can be very high, corresponding to ultra-wideband (UWB) operation, due to short virtual pulses. X-Y antenna scanning can produce range-gated surface holograms from quadrature data. Multiple range gates can produce stacked-in-range holograms. Motion and vibration can be detected by changes in interference patterns within a range-gated zone.

Abstract: In various aspects and embodiments, incident electromagnetic radiation is received through a subwavelength aperture in a lens, the subwavelength aperture being defined by a substrate encased in a dielectric medium.

Abstract: In an azimuth detecting apparatus, a receiver includes a plurality of first antenna elements and a second antenna element. The first antenna elements are arranged at first intervals d1 to form an array. The second antenna element is arranged to define a second interval d2 between itself and one of the first antenna elements which is located at an end of the array, where d2 is less than d1. A first azimuth detector detects, within a first azimuth detection area whose angular range is defined by d1, the azimuth of a target based on the signals generated by all the first antenna elements. A second azimuth detector detects, within a second azimuth detection area whose angular range is defined by d2, the azimuth of the target based on the signals generated by the second antenna element and the first antenna element located at the end of the array.

Abstract: A radar device includes a transmission antenna and a reception antenna having a plurality of antenna elements. The radar device switches the antenna elements in synchronization with a modulation cycle, thereby obtaining a reception signal. At this time, the radar device obtains the reception signal by switching the antenna elements using a first measurement phase and a second measurement phase having different switching cycles as one set. The radar device calculates an azimuth sine value sin ?1 from the reception signal in the first measurement phase and also calculates an azimuth sinusoidal value sin ?2 from the reception signal in the second measurement phase. Then, the radar device calculates a relative velocity V from the azimuth sine value sin ?1, the azimuth sine value sin ?2, an interval time difference ?t between switching cycles, and an inter-antenna element spacing d.

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 field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, comprises a multi-part tubular mast having devices for fixing a solar panel and a radar antenna; an elongate radar antenna in an environment-protective casing, which, with an electronics unit, forms a radar system for synthesized radar detection of an aircraft in a radar coverage area; a central processing unit for identifying on the basis of information from the radar system an aircraft which is in a zone of the radar coverage area and which on the basis of radar information such as direction, distance and/or speed computes a collision danger area; and a high-intensity light system and radio transmitter system that can be activated by the central processing unit upon detection of an aircraft in a collision danger area.