Abstract: The present invention is intended to provide a system for determining the precise launch point of ballistic missiles, and may additionally provide the capability of neutralizing said threats. The invention provides a mobile object information means configured to classify electromagnetic frequency activity within satellite and land based commercial and private broadcast and telecommunications spectra in a given geographical area, said means also configured to classify associated area weather normality and anomalies. The system includes a software algorithm configured to extract from said database, a missile launch in a given geographical zone by “tagging” an electromagnetic wave disturbance caused by the high intensity initial fuel burn of said missile launch.

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

Abstract: A method for automatic association of moving target indications from at least one entity traveling along a route. A moving target indicator radar is used to detect a plurality of moving target indication data. The moving target indication data proximate to the identified route is selected and presented in a distance-time graph, such that each selected moving target indication data has a unique distance along route and a unique observation-time value. The selected moving target indication data are then transformed from the distance-time coordinate to a slope-intercept coordinate, such that co-linear moving target indication data in the distance-time coordinate are transformed into a plurality of points superposed together with nearly identical slope values and nearly identical distance intercept value. The superposed points are mapped back to the distance-time coordinate, and the moving target indication data corresponding to the superposed points are thus associated.

Abstract: A method of recognizing a radar target comprises producing a sequence of Doppler spectra of radar returns form a scene and producing therefrom a sequence of Doppler feature vectors for a target in the scene. Hidden Markov modelling (HMM) is then used to identify the sequence of Doppler feature vectors as indicating a member of a particular class of targets. HMM is used to identify the sequence of Doppler feature vectors by assigning to each feature vector an occurrence probability by selecting a probability distribution or state from a set thereof associated with a class of targets, multiplying the occurrence probabilities together to obtain an overall probability, repeating for other probability distributions in the set to determine a combination of probability distributions giving highest overall probability for that class of target, then repeating for at least one other class of targets and selecting the target class as being that which yields the highest overall occurrence probability.

Abstract: Methods and apparatus for early detection and identification of a threat such as individuals carrying hidden explosive materials, land mines on roads, etc. are disclosed. Methods comprise transmitting radar signals in the direction of a potential threat, measuring the energy in reflected signals, dynamically generating a threat threshold value from signals received from multiple areas and comparing the energy in the reflected signals corresponding to different areas to the generated threat threshold value. The threat threshold value may be generated by averaging the weighted reflected energy measured from different areas during a single scan of a region including the different areas. The contribution to the threshold from different areas is weighted in some embodiments as a function of the distance from the transmitter and/or receiver to the particular area. Analysis of areas and treating different areas as segments facilitates accurate analysis and display of threat information.

Abstract: cosmic background radiation from the big bang is spread across the entire sky.when a stealth aircraft flies through it, it blocks out the radiation. this makes a moving hole in the radiation.with the proper-receiving equipment, it is posible to detect, track, and target an aircraft.

Abstract: A method and system are disclosed for detecting objects of interest in a target area using ultra wide band (UWB) RF signals. A transmitter and antenna array generate ultra wide band RF impulsive signals that are used to probe a target area that may include an object of interest. An antenna and a signal processor receive return signals from the target area and process the return signal to generate a set of coordinates. The coordinates of the processed return signals are compared to coordinates of known objects in a pre-existing database to determine whether there is a match between the return signal and a known object. When there is an indication of a match, the existence of the known object is displayed to an operator of the system.

Abstract: Imaging methods and systems for concealed weapon detection are disclosed. In an active mode, a target can be illuminated by a wide-band RF source. A mechanically scanned antenna, together with a highly sensitive wide-band receiver can then collect and process the signals reflected from the target. In a passive mode, the wide-band receiver detects back-body radiation emanating from the target and possesses sufficient resolution to separate different objects. The received signals can then be processed via a computer and displayed on a display unit thereof for further analysis by security personnel.

Abstract: Imaging methods and systems for concealed weapon detection are disclosed. In an active mode, a target can be illuminated by a wide-band RF source. A mechanically scanned antenna, together with a highly sensitive wide-band receiver can then collect and process the signals reflected from the target. In a passive mode, the wide-band receiver detects back-body radiation emanating from the target and possesses sufficient resolution to separate different objects. The received signals can then be processed via a computer and displayed on a display unit thereof for further analysis by security personnel.

Abstract: An apparatus for identifying a buried object using ground penetrating radar (GPR) in a system containing at least one GPR sensor, comprises a data processor for detecting spatial correlations in data received from a GPR sensor in the apparatus and an image processor capable of building a data structure corresponding to an image of the buried object from data processed by the data processor. A method for identifying a buried object using GPR in a system containing a GPR sensor comprising detecting spatial correlations in data received from the GPR sensor in the system and building a data structure corresponding to an image of the buried object from the received data.

Abstract: A combined defense and navigational system on a naval vessel is disclosed. The disclosed system includes a track-while-scan pulse radar which is controlled to provide either navigational information or tracking information on selected targets. Additionally, the disclosed system includes a plurality of guided missiles, each of which may be vertically launched and directed toward intercept of a selected target either by commands from the track-while-scan radar or from an active guidance system in each such missile.

Abstract: In a method for determination of the length of objects in traffic, especially passenger cars, trucks, buses, motorbikes, bicycles and pedestrians, radar signals are transmitted by a vehicle, the radar signals are reflected by an object being measured, the reflected radar signals are received in the vehicle, the frequency spectra of the reflected radar signals are evaluated, and the reflection peaks contained in the frequency spectra are determined. Length measurement, by means of known radar sensors, from a vehicle is made possible by the fact that the width of the reflection peaks is determined, and that the length of the object being measured is determined by means of the determined width.

Abstract: A stationary object detection method for a scanning radar wherein, of peaks generated based on a radar signal reflected from a target, peaks having substantially the same frequency are grouped together, and a decision is made as to whether or not the frequency of the grouped peaks is equal to/higher than a predetermined value, and wherein if the peak frequency is equal to or higher than the predetermined value, then a decision is made as to whether or not the number of grouped peaks is equal to or greater than a predetermined number and, if the number of peaks is equal to or greater than the predetermined number, it is decided that the target is an overhead bridge candidate or an overhead bridge.

Abstract: A system for determining the scan type of a signal, such as a radar signal, includes a scan detector, a transformer (e.g., an FFT algorithm), a correlator, and a decision block. The signal is received and processed by the scan detector. The scan detector provides an envelope signal, representing the scan type of the received signal. The envelope signal is transformed, typically from a time domain signal to a frequency domain signal, by any of several processes including a Fourier transform, a Laplace transform, an FFT, or a DFT. The transformed envelope signal is compared to several scan data sets by the correlator. Each scan data set represents a particular scan type. If the decision block determines that the comparison between the transformed envelope signal and a scan data set meets (or exceeds) a degree of similarity, the scan type of the received signal is determined to be the scan type of that scan data set.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. Data is provided that specifies one or more emitters or emitter types desired for detection. An algorithm evaluates the cost, in terms of receiver resources, of using one or more different detecting methods to create a receiver scan strategy for the desired emitters or emitter types.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. Typically, the minimum dwell duration of a dwell is the maximum pulse repetition interval (PRI) of the emitters that the dwell is intended to cover. However, it may be possible to reduce the minimum dwell duration when the overall probability of intercept of a particular dwell may be met with a shorter dwell duration. A system and method are provided to detect this condition and reduce the dwell duration of the dwell if appropriate.

Abstract: The present invention relates to a system for using signals scattered by targets to determine position and velocity for each of the targets and comprises a set of transmitters and receivers of electromagnetic or acoustic signals, said transmitters and receivers dispersed to known points. Each pair of transmitter and receiver, mono-static or bi-static, is named a measuring facility. The ranges of the transmitters are chosen so that a target at an arbitrary point within the position space can be measured via scattering in the target by at least four, but preferably many more, measuring facilities.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. Data is provided that specifies one or more emitters or emitter types desired for detection. An algorithm evaluates the cost, in terms of receiver resources, of using one or more different detecting methods to create a receiver scan strategy for the desired emitters or emitter types.

Abstract: Targets imaged by radar systems typically have shadows associated with them. Target detection and identification is enhanced by analyzing the shadow characteristics of a suspected target. Features of the shadow cast by the suspected target enhance the identification process. Authenticating the suspected target shadow as being indeed cast by the target comprises a) Generating a radar image using radar returns, the radar image containing both the target and its suspected target shadow; b) Forming a pentagonal perimeter adjacent to the target (within the radar image), the pentagonal perimeter chosen to contain the suspected target shadow, the pentagonal perimeter separating the target from its suspected target shadow; c) Testing the suspected target shadow within said pentagonal perimeter to authenticate that the suspected target shadow is cast by the target. One aspect of the testing performed on the suspect target shadow uses a 2 by 2 dilation and majority filter.

Abstract: A method, apparatus, and system for automatic detection of targets from radar data are disclosed. Ground moving target indicator radar is used to collect radar data which is then filtered to suppress intensity of the clutter ridge. For each working point in a set of radar data, a working first-sense circular transmit/first-sense circular receive radar cross section, a working first-sense circular transmit/second-sense circular receive radar cross section, and a working asymmetry angle are calculated from a scattering matrix, then analyzed to classify the working point as a target point or a clutter point. This analysis suitably is performed by comparing data calculated for each working point to basis data collected in a look-up table in which combinations of a first-sense circular transmit/first-sense circular receive radar cross section, a first-sense circular transmit/second-sense circular receive radar cross section, and an asymmetry angle have been classified as target points or clutter points.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. In one embodiment of the invention, a set of models is used to compute antenna characteristics as a function of frequency, gain, power, beam width, scan and polarization. Data such as actual antenna gain vs azimuth for several polarizations may also be used, thereby reducing the amount of data needed for the antenna modeling purposes.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. However, it is possible that the scan strategy is not realizable because of capacity constraints within the receiver system itself. One embodiment of the invention provides a method for detecting and correcting such a situation.

Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. A rule-based system is provided for determining how emitters should be detected by a detection system. Rules may be used to prioritize certain emitters with respect to other emitters. The rules may also specify parameters for emitter modes, such as probability of intercept, turn-on range, detect-by range, tolerance, tolerance direction, scan periods, and other parameters. The rules may be used to compute the revisit time for the receiver. Multiple sets of rules may be created and a scan strategy may be computed based upon the selected rule set.

Abstract: A method, apparatus and computer-readable medium having stored thereon instructions for automatic detection of desired targets from radar data are disclosed. For each working point in a set of radar data, from a scattering matrix derived from collected radar data, a working total radar cross section and a working asymmetry angle are calculated. The working total radar cross section and the working asymmetry angle are then evaluated to determine whether the working point should be classified as a target point or a clutter point. The method and apparatus suitably may employ a two-dimensional table of total radar cross sections and asymmetry angles previously classified as signifying target points or clutter points. Reading from the look-up table, the working point is classified as a target point or a clutter point.

Abstract: A commercial airliner (10) carries a sensor that detects a characteristic (21) associated with a man portable missile (20). Raw sensor data is transmitted via a wireless data-link (41) to ground stations (31-33) that process the airliner transmission and determine both the presence of the missile and a precise aircraft position. Countermeasures are fired to detonate within a close proximity of airliner in order to divert the detected missile.

Abstract: Bistatic/multistatic radar system concept for purposes of interrogating difficult and obscured targets in urban environments via the application of low-altitude “smart” or “robotic-type” unmanned air vehicle platforms. A significant aspect of the invention is the formulation of a unmanned air vehicle system concept that implements self-adaptive positional adjustments based on sensed properties such as phase discontinuities of the propagation channel.

Abstract: Methods and Apparatus for early detection and identification of a threat, and alerting against detected threats, such as individuals wearing or carrying explosive materials and/or weapons, e.g., suicide bombers and other terrorists, at a great enough distance to limit loss of life and destruction of property are disclosed. The methods comprise transmitting a signal in the direction of a potential threat, measuring the detected reflected signal, and comparing the signal level with a threshold indicative of a threat. A monitor is employed to display the threat and attributes of the detected signals. The invention further illuminates the suspicious individual(s) with a Laser illuminator/designator and provides information about the distance to the suspicious individual(s).

Abstract: A millimeter wave imaging system that includes at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a target may be obtained by moving the target across the field of view of the scanning antenna. In a preferred embodiment the antenna is only 4.5 inches in length and constructed from WR-10 waveguide with inclined slots cut in one of the narrow walls at 79 mil spacings. This geometry creates a frequency-scanned antenna spanning a 20 degree vertical field of view over a 75.5-93.5 GHz operational band of the sensor, starting at approximately 1 degree below horizontal at 93.

Abstract: Methods and Apparatus for early detection and identification of a threat, and alerting against detected threats, such as individuals wearing or carrying explosive materials and/or weapons, e.g., suicide bombers and other terrorists, at a great enough distance to limit loss of life and destruction of property are disclosed. The methods comprise transmitting a signal in the direction of a potential threat, measuring the detected reflected signal, and comparing the signal level with a threshold indicative of a threat. A monitor is employed to display the threat and attributes of the detected signals. The invention further illuminates the suspicious individual(s) with a Laser illuminator/designator and provides information about the distance to the suspicious individual(s).

Abstract: A system for determining the scan type of a signal, such as a radar signal, includes a scan detector, a transformer (e.g., an FFT algorithm), a correlator, and a decision block. The signal is received and processed by the scan detector. The scan detector provides an envelope signal, representing the scan type of the received signal. The envelope signal is transformed, typically from a time domain signal to a frequency domain signal, by any of several processes including a Fourier transform, a Laplace transform, an FFT, or a DFT. The transformed envelope signal is compared to several scan data sets by the correlator. Each scan data set represents a particular scan type. If the decision block determines that the comparison between the transformed envelope signal and a scan data set meets (or exceeds) a degree of similarity, the scan type of the received signal is determined to be the scan type of that scan data set.

Abstract: In order to occur a collision warning to prevent the collision in accurate by detecting the preceding vehicle or target, a vehicle lane position estimation device comprising a means for measuring a distance between said host vehicle and said preceding vehicle or a oncoming vehicle, a direction angle from said host vehicle, an angular velocity and a velocity of said host vehicle, a means for calculating lateral and longitudinal distance between said host vehicle and said preceding vehicle or said oncoming vehicle, a means for capturing a front stationary object, a means for obtaining movement of the preceding vehicle or position of the oncoming vehicle, and a means to estimate a lane position of said front stationary object from a relationship of the stationary object being captured and the preceding vehicle being obtained and a positional relationship with the oncoming vehicle.

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

Abstract: An adaptive broadcast radar system for tracking targets is disclosed, the radar system includes a transmitter having sub-apertures and a receiver having sub-apertures. The transmitter sub-apertures generate and code a signal waveform. The signal waveform is coded with data about the transmitter, including the degrees of freedom. The receiver receives signals comprising direct path signals and scattered signals correlating to the signal waveforms from the transmitter. The receiver includes a signal processor that regenerates a transmit beam for the coded data, delay, and doppler information from the received signals. The signal processor generates data quads encapsulating the information.

Abstract: A method and system for are provided for detecting one or more radar targets of interest in the presence of jamming signals. A plurality of sub-arrays are formed from an antenna array. Sub-array beams are adaptively formed so as to point one or more nulls in one or more respective directions corresponding to one or more jammers. A super-resolution technique is applied to determine a count of the one or more radar targets and to determine the corresponding direction of arrival.

Abstract: A system and method (32) for measuring line-of-sight angular rates for all-weather precision guidance of distributed projectiles (16) and a guidance system (10) based thereon. In accordance with the novel method (32) for measuring line-of-sight angular rates, first the range rates of the target (14) relative to at least two projectiles (16) is determined, as well as the position and velocity of each projectile (16). Then, the line-of-sight angular rate of the target (14) relative to at least one projectile (16) is computed from the range rates, positions, and velocities. In the illustrative embodiment, the range rate of the target (14) relative to a projectile (16) is determined based on a monostatic target Doppler measurement, a monostatic projectile Doppler measurement, a bistatic Doppler measurement of the target (14) by the projectile (16), and the carrier frequency of a data link (26) between the projectile and the shipboard system.

Abstract: A method for estimating the curvature in a road is disclosed. The method measures an azimuth angle range and relative velocity between a host and a target vehicle, which determines whether a host vehicle is changing lanes or whether a target vehicle is changing lanes. The method calculates a heading angle of the host vehicle and calculates a corrected azimuth angle by adjusting the measured azimuth angle by the value of calculated heading angle. This method selects a curve that minimizes the mean square error between the curve and selected targets; and determines an equation that describes the curve, wherein the equation is used to predict the path head of the host vehicle.

Abstract: The present invention is an apparatus and method for displaying a foreign body in a relatively uniform mass having similar electromagnetic impedance as the foreign body comprising of at least two ultra wide band holographic radar units adapted to generate, transmit and receive a plurality of 12-20 GHz frequency signals in a dual linear antenna with slant-angle illumination. The invention may be utilized to obtain qualitative and quantitative data regarding the composition of the object under investigation.

Abstract: A method and system provide a multi-sensor data fusion system capable of adaptively weighting the contributions from each one of a plurality of sensors using a plurality of data fusion methods. During a predetermined tracking period, the system receives data from each individual sensor and each data fusion method is performed to determine a plurality of reliability functions for the system based on combining each sensor reliability function which are individually weighted based on the S/N (signal-to-noise) ratio for the received data from each sensor, and a comparison of predetermined sensor operation characteristics for each sensor and a best performing (most reliable) sensor. The system may dynamically select to use one or a predetermined combination of the generated reliability functions as the current (best) reliability function which provides a confidence level for the multi-sensor system relating to the correct classification (recognition) of targets and decoys.

Abstract: A harmonic radar nonlinear junction detector system for detecting concealed weapons, electronics, and other man-made objects utilizing state-of-the art wireless technology, circuit fabrication, signal synthesis, and computer processing techniques to detect and characterize man-made objects possessing nonlinear junctions. The system transmits a pair of low power waveforms and a receiver within the system is coherently tuned to harmonics of the transmitted frequencies of the waveforms to detect man-made metal objects and electronics that contain non-linear junctions. The receiver is also capable of receiving inter-modulation products reflected from the man-made objects that are a result of using two incident signals. The system uses two signal sources generating user-definable waveforms of variable frequencies in order to provide enhanced discrimination and target identification abilities via the processing of returned inter-modulation products.

Abstract: An active short pulse fuze system for arming on a true target acquisition and firing only on the loss of the acquired target signal. The sea surface is tracked by means of a sea tracking loop A target threshold is established and is coupled to the sea tracking loop so as to expand and contract with the sea tracking. A return signal will pass the target threshold only when there is an abrupt reduction in range, indicating the presence of a target. The presence of this signal will arm the firing circuit. An abrupt increase in range will indicate the loss of the target and cause immediate detonation of the warhead.

Abstract: A method of recognising a radar target comprises producing a sequence of Doppler spectra of radar returns form a scene and producing therefrom a sequence of Doppler feature vectors for a target in the scene. Hidden Markov modelling (HMM) is then used to identify the sequence of Doppler feature vectors as indicating a member of a particular class of targets. HMM is used to identify the sequence of Doppler feature vectors by assigning to each feature vector an occurrence probability by selecting a probability distribution or state from a set thereof associated with a class of targets, multiplying the occurrence probabilities together to obtain an overall probability, repeating for other probability distributions in the set to determine a combination of probability distributions giving highest overall probability for that class of target, then repeating for at least one other class of targets and selecting the target class as being that which yields the highest overall occurrence probability.

Abstract: An HF radar system comprises a transmitting system, a receiving system, a signal processing system and a frequency management/ionospheric sounding system. The transmitting system comprises a transmitting antenna array configured to transmit a beam in a near vertical direction and a transmitting device arranged to drive the transmitting antenna array at frequencies suitable for downward refraction by the ionosphere. The receiving system comprises a receiving antenna array configured to receive returning signals from a target area returning to the receiving antenna array via refraction at the ionosphere. The signal processing system comprises a digital data processing system. The frequency management/sounding system comprises cooperating transmitting and receiving systems sending H-F signals to the ionosphere and analysing the returning signals. Alternatively, the system may have a duplexed antenna array.

Abstract: A method and bistatic synthetic aperture radar (SAR) imaging system generate an image of a target area without knowledge of the position or velocity of the illuminator. The system includes an illuminator to illuminate a target area with a null-monopulse radiation pattern interleaved with a sum radiation pattern. The illuminator adjusts the phase terms of the sum radiation pattern to maintain a static electromagnetic field pattern at the target area. A receiver receives the radiation patterns reflected from the target area and generates phase compensation terms by correlating a measured electromagnetic vector field with the known static electromagnetic vector field. The phase compensation terms are used to generate an image of the target area.

Abstract: A system, method, and computer program product for alerting a flight crew of weather radar return data collected, yet not presently being displayed. The system includes a memory, a processor, and an output device. The memory stores radar return information in a three-dimensional buffer. The processor determines if any radar return information stored in a three-dimensional buffer is within a threshold distance from an aircraft's present position and generates an image based on target data stored in the three-dimensional buffer and selected display parameters. The processor also generates a target alert if any target data is determined to be within a threshold distance from the aircraft's present position and is not included in the generated image. The output device presents the generated target alert.

Abstract: The invention is a method and apparatus for determining the shape and location of objects by trilateration based on the output of a plurality of range sensors. The range measurements from a plurality of sensors are correlated with each other to identify one or more potential objects. With respect to each potential object, it is assumed that the object can be one of a finite number of possible predefined shapes. For each potential object, a metric is calculated for each of the predefined shapes using the set of range measurements upon which the potential object is based defining the likelihood that the set of readings correspond to an actual object of that predefined shape. Each potential object is then assumed to have the predefined shape that yielded the lowest metric (i.e., that yielded the metric that indicates the highest likelihood that the object has the corresponding shape). The list of potential objects is then ordered according by their calculated metrics from lowest to highest.

Abstract: A plurality of sub-antennas in a two-dimensional plane antenna 11 or the like receive milliwaves from concerned object 20. AnA/D converter 12 converts the received signal to digital data. A signal processor 13 executes signal processing on the digital data for displaying images on a monitor 15. Prior to the measurement, a calibration signal source 14 generates a calibration signal. A phase compensator 133 in the signal processor 13 obtains phase compensation data, and compensates measurement data.

Abstract: A monostatic radar signature is estimated of a sample object which is made of the same material as the target object. Using this monostatic radar signature estimation, the radar cross-section (RCS) per unit area is calculated for the sample object as a function of aspect angle and frequency. The target object is modeled so as to represent plural three-dimensional elements within the target object, and so as to associate an RCS per unit area value with every three-dimensional scattering element. An incoherent summation is performed of the three-dimensional scattering elements as a function of azimuth and frequency. One or more monostatic radar signatures can be estimated, and, correspondingly, one or more RCS per unit area values can be calculated. Every RCS per unit area value thus obtained can be incorporated in the modeling of the target object.

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

Abstract: In a radar system, sampled aperture data are received from an antenna array. The sampled aperture data include data that do not correspond to echo returns from a beam transmitted by the antenna. A covariance matrix is generating using the sampled aperture data. An eigenvalue decomposition is performed on the covariance matrix. A direction of arrival is determined from which at least one jammer is transmitting a signal included in the sampled aperture data, based on the eigenvalue decomposition.

Abstract: There is provided a method for tracking a group having at least two targets. The method may comprise selecting the at least two targets from a plurality of targets. The at least two targets may be selectable based upon their respective target datum thereof. Thereafter, a dual gate surrounding each respective one of the at least two targets is defined, wherein a movement of each dual gate is synchronized with a movement of respective one of the at least two targets corresponding thereto. The dual gate of each respective one of the at least two targets may then be associated with each other to form the group.