Abstract: The present invention relates to a system (300) for reducing or cancelling unwanted signals when detecting objects of interest with a detection system (200). The detection system thereby is an antenna based system using two or more receive beams as echo response to an emission signal. The system (300) for reducing or cancelling unwanted signals comprises an input means (310) adapted for obtaining from said antenna system (210) receive signals from a first receive beam and receive signals from at least one second receive beam responsive to the same emission signal. It furthermore comprises a coupling means (320) adapted for coupling the receive signals from the first receive beam to the receive signals from the at least one second receive beam, so as to obtain a detection signal for the objects of interest with suppressed unwanted signal contribution.

Abstract: A method of detecting a target in a room using a radar system having a transmitter for irradiating the object, a sensor for receiving reflected radiation, and circuitry for analyzing the reflected radiation to determine at least one characteristic thereof, the method including determining at least one parameter for each wall of a plurality of walls of a room containing the target; determining possible signal paths between the target and the sensor for paths including up to N reflections based on the at least one parameter of each wall and the location of the sensor; calculating target image locations based on the possible signal paths; and processing the received radiation to determine a target location based on target image locations.

Abstract: A system and method of detecting moving targets comprises transmitting electromagnetic waves rays from a plurality of transmitters at sequential; receiving reflected waves into a plurality of receivers after each transmission; the compilation of the reflected waves from the plurality of receivers for each transmission representing a data frame; forming a signal that monitors changes between the two sets of frames; at least one processor operating to process and compare frames; forming a difference image using a back-projection algorithm; scanning the difference image using a constant false alarm rate (CFAR) window; the CFAR window scanning the entire difference image and identifying a list of points of interest and eliminating the sidelobe artifacts present in the difference image thereby creating CFAR images; processing the CFAR images using morphological processing to create a morphological image; determining the number of clusters present in the morphological image; using K-means clustering to indicate the

Abstract: A synthetic-aperture radar system, and related operating method, for the monitoring of ground and structure movements, particularly suitable for emergency conditions, characterized by a ground based platform with polarimetric capabilities, that able to quickly acquire, embeddedly process and post-process data by a novel data acquisition “On the Fly” mode of operation, reducing by at least an order of magnitude the data acquisition time. The inventive system characteristics allows to achieve on-field measurement results on three-dimensional maps georeferenced to absolute coordinate systems (WGS84, Gauss-Boaga, and so on).

Abstract: A new approach to radar imaging is described herein, in which radar pulses are transmitted wi th 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: A land-based smart sensor system and several system architectures for detection, tracking, and classification of people and vehicles automatically and in real time for border, property, and facility security surveillance is described. The preferred embodiment of the proposed smart sensor system is comprised of (1) a low-cost, non-coherent radar, whose function is to detect and track people, singly or in groups, and various means of transportation, which may include vehicles, animals, or aircraft, singly or in groups, and cue (2) an optical sensor such as a long-wave infrared (LWIR) sensor, whose function is to classify the identified targets and produce movie clips for operator validation and use, and (3) a supercomputer to process the collected data in real-time. The smart sensor system can be implemented in a tower-based or a mobile-based, or combination system architecture. The radar can also be operated as a stand-alone system.

Abstract: A radar system, apparatus, and method includes at least one radar transmitter for transmitting an electromagnetic waveform; a receiving antenna comprising a plurality of receiving antenna elements and delay lines, each of the plurality of receiving antenna elements receiving the return signal operatively associated with a predetermined delay line; each delay line having a delay length which produces a different phase delay in the return signal; the different phase delays producing substantially different antenna patterns for the received signal at a given frequency; at least one processor operatively connected to receive data from the plurality of delay lines; the at least one processor operating to analyze the substantially different beam patterns for a given frequency; whereby the processing of the data produces results indicating the presence and location of a target.

Abstract: A radar device includes an antenna, from which a detection signal is transmitted while the antenna being rotated and by which a reflective wave of the transmitted detection signal is received to detect echo data, wherein image data is generated based on the detected echo data, a continuity detecting module for detecting a planar continuity of the currently detected echo data with respect to a pixel concerned in the image data, a behavior data generating module for generating behavior data indicative of a behavior of the echo data for a predetermined number of scans of the past in the pixel concerned based on behavior determination data, and an echo kind determining module for determining a kind of the echo data of the pixel concerned based on the planar continuity and the behavior data.

Abstract: A motion compensation method and system is included in a radar antenna system mounted on a moving platform which is subject to pitch, yaw and roll. The radar antenna system includes a main array antenna, and an auxiliary antenna. The auxiliary channel associated with the auxiliary antenna utilizes roll, pitch and yaw angle motion compensations as its auxiliary antenna always steers a horizontal fan shape beam at the horizon to blank any surface (land or sea) based EM interferences. Such motion compensations are provided by a ship motion compensator component and process included within the antenna system. The ship motion compensator component in response to platform motion signals indicative of changes in platform motion angles generates new sets of values using an initial set of weighting coefficient values as a function of such angle motion changes.

Abstract: A system and method for determining the geolocation of a signal emitter moving at an unknown velocity by combining signal data of a target detection platform (e.g., a radar system) and signal data collected by two or more moving signal collection platforms (e.g., RF signal receivers). In one embodiment, the target detection platform determines tentative location and velocity of the signal emitter, and the signal collection platforms are configured to perform TDOA and/or FDOA analysis of the collected signal data corresponding to a signal of the signal emitter. In one embodiment, solutions provided from the TDOA and/or FDOA analysis are unbiased by using the tentative velocity of the signal emitter, and the geolocation of the signal emitter is determined by matching the TDOA/FDOA solutions and the detected tentative location.

Abstract: A process for detecting and discriminating a particular target, such as an ambulating human, amidst an environment crowded with other objects or humans having similar doppler profiles to the desired target. A method according to one embodiment includes generating an initial radar image corresponding to a received doppler profile of a target, and generating a matched filter signal corresponding to the received doppler profile. The matched filter signal is correlated with subsequently received radar images to detect and discriminate the target.

Abstract: A system and method for labeling feature clusters in frames of image data for optical navigation uses distances between feature clusters in a current frame of image data and feature clusters in a previous frame of image data to label the feature clusters in the current frame of image data using identifiers associated with the feature cluster in the previous frame of image data that have been correlated with the feature clusters in the current frame of image data.

Abstract: A method for processing returns from a sensor, such as a radar system, in order to identify targets is provided. The method uses a track before detect routine to integrate data from several scans in order to give better discrimination. In running the track before detect routine however a number of possible target motions are postulated and the data combined accounting for such motions. A result above a threshold may then be indicative to a target present and moving with the postulated velocity. The method gives more accurate target detection as the combined data at the correct target motion postulate is more consistent than transient noise and clutter. Once a target has been identified it is preferably removed from the data set in searching for additional targets.

Abstract: There is provided a sensor for use generally within the signal processing unit of a radar system. The sensor enables entity returns to be classified according to the velocity of the entity and thus allows returns to be processed according to classification. In particular the sensor comprises a first processing means that filters an input signal using a narrow-band notch filter to output a wideband output. In particular the sensor comprises a second processing means that filters an input signal using a wide-band notch filter to output a narrowband output. The invention provides for the comparison of the outputs to determine how the entity return is to be classified.

Abstract: An apparatus and method for identifying a human being and an animal are disclosed to properly identifying whether or not a target is a human being or an animal. The apparatus for distinguishing between a human being and an animal includes: a target stimulation unit generating a stimulation signals for selectively stimulating the senses of a human being and an animal and providing the generated stimulation signal to a target; and a target identifying unit detecting the reaction of a target to the simulation signal to identify whether or not the target is a human being or an animal.

Abstract: A frequency modulated continuous wave (FMCW) radar is described. The radar includes a first discriminator for receiving a portion of the swept frequency signal generated by a frequency sweep generator and for producing a reference difference-frequency signal of frequency equal to the difference between the frequency of the swept frequency signal and the frequency of a time displaced swept frequency signal derived from the swept frequency signal. An analogue-to-digital converter is provided for sampling the target difference-frequency signal at a rate derived from the frequency of the reference difference-frequency signal. A processor (88) for determining frequency components of the digitized target difference-frequency signal is arranged to determine for at least one frequency component of the digitized target difference-frequency signal any phase difference between frequency sweeps of said swept frequency signal. The radar may be used for detecting foreign object debris (FOD) on runway surfaces and the like.

Abstract: Methods to quantify the amount of radial platform motion of a portable sensor are described. In an exemplary embodiment, the method uses the frequency domain phase data in the range bin corresponding to a large stationary object. A correction factor is computed and applied back into the time domain samples prior to processing by Doppler filters used to measure motion in the scene.

Abstract: A method to process a radar echo signal is described. The method determines the value of at least one target motion parameter by selecting from a plurality of possible test values (VR1, . . . , VRN) one value (VR) which maximizes a functional defined over the radar echo signal. The method further performs a correction of the radar echo signal based on the value (VR) which is determined by the at least one motion parameter. The functional is the time derivative of the radar echo signal or a function dependent from the derivative.

Abstract: Methods and systems consistent with the present invention allow identification of a true signal contained in a signal containing the true signal and noise. In general, digital signal information representing a signal of interest plus noise is utilized by the present invention. The first N samples of digital signal information are stored with the Nth sample being stored in manner which renders it accessible for additional operations. A specially selected set of weights are applied to the buffered N samples and, additionally, phase rotation is applied to the Nth sample. The phase rotated Nth sample and weighted samples are combined using a first equation, described in more detail below. The resulting signal, which exhibits an increased Signal-to-Noise ratio (SNR) and may be more effectively utilized in subsequent MTI processing by virtue of the operations performed on the previous N samples as described herein, is then available for further processing using conventional techniques.

Abstract: Apparatus for providing moving target indicator (MTI) filtering in the presence of clutter for a radar receiver employing digital pulse compression to provide at an output a compressed digital pulse for application to the input of a MTI digital filter, including a digital adaptive filter of the same weight as the MTI filter and operative to receive the compressed pulse to provide at outputs of the filter a set of weighted filter coefficients, wherein the weighted coefficients are applied to the MTI filter during a predetermined clutter mode.

Abstract: A method and system for SNR enhancement in pulse-Doppler coherent target detection for applications in the fields of radar and ultrasound. In accordance with the method of the invention, complex signals are obtained for each of two or more sub-intervals of the time-on-target interval, allowing simultaneous range and Doppler measurements. A coherent integration is the performed on the signals to generate complex-valued folded matrices. The folded matrices are unfolded and target detection is then performed in a process involving one or more of the unfolded matrices. A pulse-Doppler coherent system is also provided configured for target detection by the method of the invention.

Abstract: An apparatus for sensing motion having a transmitter for transmitting a carrier signal; a frequency control connected to the transmitter for controlling the frequency of the carrier signal; a first receiver for receiving the reflected transmitted carrier signal; a second receiver for receiving the reflected transmitted carrier signal, the second receiver being placed out of phase by less than a wavelength of the carrier signal from the first receiver; means for subtracting the carrier signal received by the second receiver from the carrier signal received by the first receiver to produce an error signal; wherein when motion is sensed by the apparatus, the error signal moves from zero thereby causing a corrective signal to be generated and sent to the frequency control, the frequency control forcing the error signal to zero.

Abstract: A method and apparatus are provided for operating a microwave detector for detecting intruders within a secured area. The method includes the steps of selecting a noise floor based upon a setting of a range setting potentiometer, detecting a magnitude of a signal reflected from a test subject within the secured area that exceeds the selected noise floor and establishing a threshold value for detecting an intruder based upon the magnitude of the detected signal and sensor mounting height.

Abstract: A radar system comprising a transmitter to transmit radar signals into a region, a receiver to receive return signals of said radar signals reflected from within the region wherein the transmitter and receiver are adapted for location on a structure at a wind farm, and a processor to process the return signals to extract wind farm associated data for said region.

Abstract: Apparatus for providing moving target indicator (MTI) filtering in the presence of clutter for a radar receiver employing digital pulse compression to provide at an output a compressed digital pulse for application to the input of a MTI digital filter, including a digital adaptive filter of the same weight as the MTI filter and operative to receive the compressed pulse to provide at outputs of the filter a set of weighted filter coefficients, wherein the weighted coefficients are applied to the MTI filter during a predetermined clutter mode.

Abstract: A scanning radar system suitable for detecting and monitoring ground-based targets includes a frequency generator, a frequency scanning antenna, and a receiver arranged to process signals received from a target so as to identify a Doppler frequency associated with the target. The frequency generator generates sets of signals, each set having a different characteristic frequency, and includes a digital synthesiser arranged to modulate a continuous wave signal of a given characteristic frequency by a sequence of modulation patterns to generate one set of signals. The frequency scanning antenna cooperates with the frequency generator to transceive radiation over a region having an angular extent dependent on the generated frequencies.

Abstract: The present invention provides a radar apparatus including: a transmission pulse group generator configured to generate: a first transmission pulse group from a first transmission pulse train formed of N first transmission pulses (N>2, where N is an integer number) having constant first time intervals t1, by thinning a first transmission pulse out of the first transmission pulse train so that all the intervals ranging from t1 to (N?1)*t1 are held by pairs of first transmission pulses selected from the first transmission pulse group; and a second transmission pulse group from a second transmission pulse train formed of M second transmission pulses (M>2, where M is an integer number) having second time intervals t2 different from the first time intervals t1, by thinning a second transmission pulse out of the second transmission pulse train so that all time intervals ranging from t2 to (M?1)*t2 are held by pairs of second transmission pulses selected from the second transmission pulse group.

Abstract: The invention relates to the general field of the detection, notably the radar detection, of mobile or fixed targets. It consists of a method making it possible mainly to qualify the blips supplied by the processing subsystem of the detection system before the latter are analysed to generate tracks, each track being assumed to represent the trajectory of a moving object that has been detected. According to the invention, an analysis duration is considered, and all of the blips detected during this period are considered. These blips are divided up into subsets, each subset corresponding to the blips that, during the analysis duration, have been detected in one and the same analysis channel defined by an initial position and a speed vector. The subsets formed in this way are then grouped together, one and the same group combining the subsets comprising blips for which the combined assertion of a plurality of attributes is verified.

Abstract: A method to process a radar echo signal is described. The method determines the value of at least one target motion parameter by selecting from a plurality of possible test values (VR1, . . . , VRN) one value (VR) which maximizes a functional defined over the radar echo signal. The method further performs a correction of the radar echo signal based on the value (VR) which is determined by the at least one motion parameter. The functional is the time derivative of the radar echo signal or a function dependent from the derivative.

Abstract: A method of extracting a radial velocity characteristic of a target from coherent pulse bursts comprising the steps of applying to data a ‘best fit’ model of the echo returns from a target in the presence of clutter to obtain a residue (error) value and minimising the error value by a predetermined method to give the best fit value for the target radial velocity. The method enables more information to be retrieved from coherent bursts than conventional methods and therefore greatly enhances performance of radiation pulse echo detection.

Abstract: In a radar system that detects relatively fast moving targets using a radar clutter map comprising a plurality of range-azimuth cells containing parameter data values indicative of time averaged echo returns for affecting alarm threshold levels at range-azimuth locations scanned by the radar system antenna, a method for detecting relatively slow moving targets in a substantially homogeneous surveillance region, the method comprising the steps of obtaining from the radar clutter map a value corresponding to parameter data of a given cell under test (CUT); determining a second parameter data value using parameter data values of other cells from the plurality of range-azimuth cells from the radar clutter map; comparing the parameter data value of the CUT with the second parameter data value; and generating a signal indicative of a target detection when the CUT parameter data value exceeds the second parameter data value by a given threshold corresponding to a target false alarm rate.

Abstract: A moving object is classified by transmitting, by a linear array of transmit antenna elements, a microwave into a surveillance area. A scattered microwave backprojected from a moving object is received by a linear array of receive antenna elements. Features are extracted from the scattered microwave related to a spiral evolution of the scattered microwave. The moving object is then classified as one of a set of possible classes according to the extracted features, and an alarm signal can be generated indicating the selected class.

Abstract: The present invention provides a radar apparatus including: a transmission pulse group generator configured to generate: a first transmission pulse group from a first transmission pulse train formed of N first transmission pulses (N>2, where N is an integer number) having constant first time intervals t1, by thinning a first transmission pulse out of the first transmission pulse train so that all the intervals ranging from t1 to (N?1)*t1 are held by pairs of first transmission pulses selected from the first transmission pulse group; and a second transmission pulse group from a second transmission pulse train formed of M second transmission pulses (M>2, where M is an integer number) having second time intervals t2 different from the first time intervals t1, by thinning a second transmission pulse out of the second transmission pulse train so that all time intervals ranging from t2 to (M?1)*t2 are held by pairs of second transmission pulses selected from the second transmission pulse group.

Abstract: Method and apparatus for simultaneous synthetic aperture radar and moving target detection. A plurality of independent radio frequency signals are generated and applied to separate radiating/receiving antenna elements. Signals are generated as basis functions, such that moving target detection and synthetic aperture radar signals are constructed from individual waveform components in space, time, frequency, and coding. Waveform components are sorted and combined at reception. Received data is simultaneously processed to extract synthetic aperture radar images and moving target indication detections.

Abstract: The proper timing or alignment for coherent or noncoherent integration of radar pulses returned from a potentially moving target is determined by determining the entropy associated with sets of range samples based on a plurality of different velocity hypotheses. That set associated with the minimum entropy is deemed to be the correct velocity hypothesis, and integration is then performed using the velocity hypothesis so determined.

Abstract: Embodiments of the invention are concerned with a radar system, and relates specifically to scanning radar systems that are suitable for detecting and monitoring ground-based targets.

Abstract: A weight calculation method begins by storing a target reflection signal of a radar pulse received via an antenna in cells corresponding to positions along with a reception timing for a plurality of processing range cells having lengths equivalent to prescribed ranges on a time axis. The method continues by calculating weights by stage for the phase and amplitude of the target reflection signal to form a reception composite beam so that arrival directions of spurious elements become zero to an arrival direction of the target reflection signal by using values stored in the plurality of processing cells. The calculating of the weights monitors changes of specific variables indicating correlation values among stages in the plurality of processing stages to stop a shift to the next processing stage at the time when the variables exceed a reference value.

Abstract: A polygonal cylindrically shaped phased array antenna forming a radar has an active aperture that focuses in any of one or more angular azimuth directions without inertia. It further includes adjacent multiple similar polygonal staves joined along their vertical edges to form a right regular polygonal cylinder. Each stave is further decomposed into flat panels, wherein each panel has a plurality of antenna elements positioned in a regular rectangular or triangular lattice. Each panel contains a beam forming network that electronically forms and steers an electromagnetic beam for purposes of transmission and subsequent reception. The panels optionally may operate as autonomous radars which when coherently combined form multiple larger antenna apertures, each capable of operating autonomously. A switching network allows transmit power and all requisite radar and control signals to be sent to and received from a selected set of panels anywhere on the polygonal cylinder.

Abstract: A system and method is presented for detecting and classifying slow-moving and hovering helicopters from a missile's look-down Doppler radar that is compatible with the existing base of Doppler radars. This approach uses definable attributes of a helicopter rotor assembly and its extended Doppler rotor return to differentiate “rotor samples” from other samples (steps 123, 125), extract features such as bandwidth, activity, angle, and shape from the rotor samples (step 127), and classify a potential target as a helicopter or other based on the extracted rotor features and the known attributes of the helicopter rotor assembly (step 129). A target report including a classification target, range, range-rate, and angle of the extended rotor return is suitably passed to a tracking processor (step 121).

Abstract: A method and system is proposed for use by a moving station (such as a jetfighter) for radar tracking of a moving target (such as an air-to-air missile). The proposed method and system involves the use of a hybrid FSK/LFM (Frequency Shift Keying & Linear Frequency Modulation) scheme for acquiring a collection of raw radar data, a first Gaussian-noise filter array of one-stage linear Kalman filters for S/N-enhancement of the raw radar data, a trilateration module, and a second Gaussian-noise filter array of one-stage linear Kalman filters for S/N-enhancement of the trilateration-resulted radar data. These features allow the radar tracking of moving objects to be more fast and accurate.

Abstract: A vehicle detector includes a detecting apparatus and a determining apparatus. If a plurality of detection points detected by the detecting apparatus forms a group of detection points, the determining apparatus sets a determining virtual window encompassing the group of detection points and determines whether the group of detection points is likely to represent the one vehicle based on a state of movement of the group of detection points with respect to the determining virtual window.

Abstract: High resolution SAR images of a target scene at near video rates can be produced by using overlapped, but nevertheless, full-size synthetic apertures. The SAR images, which respectively correspond to the apertures, can be analyzed in sequence to permit detection of movement in the target scene.

Abstract: A method and system for SNR enhancement in pulse-Doppler coherent target detection. In accordance with the method of the invention, complex signals are obtained for each of two or more sub-intervals of the time-on-target interval, allowing simultaneous rang and Doppler measurements. A coherent integration is then performed on the signals to generate complex-valued folded matrices. The folded matrices are unfolded and target detection is then performed in a process involving one or more of the unfolded matrices. A pulse-Doppler coherent system is also provided configured for target detection by the method of the invention.

Abstract: The Ground Moving Target Indicator (GMTI) target detection accuracy test system receives, compares and analyzes GMTI test data that is formatted according to the NATO-EX (v.2.01) Standard. The GMTI target detection accuracy test system also uses Global Positioning System (GPS) data from the objective target and target reports generated by the GMTI sensor to display the simulation test results. At the conclusion of the GMTI sensor test, both the GPS and GMTI data are collected and compared using a computer processor and the results are displayed using the MATLAB® program to better indicate detection accuracy and provide a higher level of target detection accuracy. A method for testing artillery target detection accuracy method is also provided for characterizing the performance of any GMTI adhering to the NATO-EX Standard and testing against an objective target outfitted with GPS instrumentation.

Abstract: Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.

Abstract: Image reconstruction approaches that use standard Cartesian-sampled, frequency-domain SAR data, which can be collected by a platform with a single radar antenna, together with its associated metadata as the input and generate an output comprised of a set of images that show the directions of moving targets, estimates of their motions, and focused images of these moving targets.

Abstract: A method for performing signal processing for accelerating moving targets, in one implementation, encompasses a method for performing coherent integration of pulses within a CPI for SMTI radar. In an embodiment, the method comprises the steps of determining the Fast Fourier Transform (FFT) for each pulse, and multiplying the FFT by a pulse compression reference function.

Abstract: A transmitter for transmitting signals to targets and a receiver having a large-diameter array antenna for receiving signals reflected from targets are included. The transmitter has a function of outputting an FMCW signal for detecting direction and velocity of the target from a transmitting antenna. The receiver includes: a plurality of correlation processors for performing correlation processing to receiving signals received by respective interference blocks configured such that the large-diameter array antenna is divided into a plurality of equal blocks; and a synthesizer for vector-synthesizing same signal components of signals outputted from the plurality of correlation processors.

Abstract: A method for performing signal processing for accelerating moving targets, in one implementation, encompasses a method for performing coherent integration of pulses within a CPI for SMTI radar. In an embodiment, the method comprises the steps of determining the Fast Fourier Transform (FFT) for each pulse, and multiplying the FFT by a pulse compression reference function.

Abstract: Pulsed or mutual interference in a pulse radar system is ameliorated by a process that includes a pulse-Doppler filter, some frequency bins of which correlate with clutter. Pulsed interference is identified, and the corresponding column vectors of a pulse-Doppler-filter-equivalent matrix are identified. The row values of the corresponding interference-affected column vectors that correlate with clutter are nulled. The vectors are orthogonalized, and then converted to measurement and correction signal vectors for application to the pulse-Doppler received signals. Vector dot products of the measurement signal vectors with the received signals are calculated, to produce pulsed interference measurements that are nominally free of clutter. The pulsed interference measurements are combined with the correction signals which are then subtracted from the received signals to produce signals that are nominally free of pulsed interference.