Abstract: A radar signal processor is disclosed having an observation mechanism for receiving a reflected wave from a target and for outputting a predetermined observation signal. The processor extracts a distance component corresponding to a distance from each observation signal. The processor further collects the respective distance components and computes an estimated value of a corresponding correlation matrix with a forgetting factor as a parameter using a method for estimating correlation matrix with exponential smoothing. The processor further estimates the presence or movement state of the target on the basis of the respective estimated values of the correlation matrices and outputs the computed values.

Abstract: Multiple signal characteristics representing an entire field of view of an FMCW (FM-CW) sensor are evaluated to determine whether the field of view has changed. Signal characteristics representing the field can be compared to representative signal characteristics obtained from previous scans. At least one signal characteristic representing at least a portion of the scene can be evaluated by comparing the signal characteristic to a dynamic threshold. The dynamic threshold can be redefined after each scan from the statistics of the signal characteristic. The dead zone of a sensor can be reduced by filtering out noise that would otherwise overshadow a signal representing the near-field region of a scene. The noise can be filtered by subtracting a polynomial curve from a time-domain signal representing the scene after fitting the polynomial curve to a representative signal generated based on previous scene scans.

Abstract: There is configured a radar or similar device that outputs received data that is currently being received and scan correlated image data in parallel with each other. Scan correlated image data and display image data resulting from received data from a display video memory 13 are input into a transitional data generator 11, and the transitional data generator 11 generates transitional data that represents an intermediate value and gradually changes from the received data into the scan correlated image data, using these signals, and inputs the transitional data into a selector 12. The received data, a FIRST or a LAST signal, and the transitional data are input into the selector 12, and the selector 12 outputs the received data if FIRST=1, and outputs the transitional data if FIRST=0, to the display video memory 13. This image data is fed back to the transitional data generator 11, and therefore it gradually changes from the received data into the scan correlated image data.

Abstract: A data code generator produces a data code, while a reference code generator produces a reference code. The data code is phase-shifted by the data code generator in a predetermined sweep range, according to a sweep command signal given by a phase difference detector. The phase difference detector compares the phase of the data code with that of the reference code to obtain phase difference data. Based on the phase difference data, a correction signal generator produces a correction signal to keep the data code in phase with the reference, code. The phase setter optimizes the phase of the data code according to the correction signal.

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

Abstract: Systems and method of detection and discrimination of targets in the presence of interference are disclosed. A system transmits a signal and then receives signals including interference and reflections of transmitted signals. The system processes the received signals and transmitted signals to generate a 2D representation of the STAP cube with one of the dimensions collapsed. The system then reduces the interference contributions and identifies angle and Doppler component of potential targets. The system then computes slices, which are one dimensional representation of cross-ambiguity functions of the received and transmitted signals. It reduces the interference contributions in the slices and determines range components of the targets.

Abstract: There are provided a differential processing unit which performs differential processing for a Mode S transponder transmission signal, an auto correlation arithmetic operation unit which performs an arithmetic operation of a degree of auto correlation between an increasing change rate and decreasing change rate of a power level in the signal which has been subjected to the differential processing, a pulse regeneration unit which regenerates a pulse based on the degree of auto correlation, which has been obtained by the auto correlation arithmetic operation processing, a pulse phase locked loop unit which performs gate processing and phase locked processing for the regenerated pulse, and a pulse decoding unit which decodes the Mode S transponder transmission signal based on the pulse which has been subjected to the gate processing and the phase locked processing.

Abstract: In a radar system, a switcher is provided for switching over between at least two different directional characteristics, in particular for different distance ranges, of at least two transmitting antennas. On the receiving side, a combined evaluation of the digitized signals of at least two receiving antennas is performed, in the manner of a correlation of the receiving antenna signals.

Abstract: Combining signals includes receiving first signals having a first frequency and second signals having a second frequency. A first weight reflecting a signal-to-noise ratio associated with a first signal is determined for each first signal, and a first signal output is generate from the first signals in accordance with the first weights. A second weight reflecting a signal-to-noise ratio associated with a second signal is determined for each second signal, and a second signal output is generate from the second signals in accordance with the second weights. The first signal output and the second signal output are combined to yield a combined signal output.

Abstract: A method for estimating channel impulse response (CIR) in a communication system includes converting RF analog signals to obtain baseband digitized signals, sampling the baseband digitized signals according to the symbol period or bit period, cross-correlating at least part of the samples and a predetermined set of training sequence symbols, and calculating the ratio of the maximum square of the modulus (power) value and the second largest value among the outputs of the cross-correlations. If the ratio is larger than a first predetermined value, the method outputs the cross-correlation values as the CIR according to the time step index of the maximum power value, and if the ratio is not larger than the first predetermined value, the method calculates the energy of a predetermined window and outputs the cross-correlation values as the CIR according to the time step index of the maximum energy.

Abstract: A method of tracking a target. The method includes the steps of acquiring a first spectral image of a scene that includes the target, designating a spectral reference window, in the first spectral image, that includes a respective plurality of pixel vectors, acquiring a second spectral image, of the scene, that includes a respective plurality of pixel vectors, and hypercorrelating the spectral reference window with the second spectral image, thereby obtaining a hypercorrelation function, a maximum of the hypercorrelation function then corresponding to a location of the target in the scene.

Abstract: A radar device is provided that can reliably display sensed image data of an object, regardless of the state of the object (echo) within a sensed range and of the surrounding environment. A behavior data detector 11 generates current level detection data by detecting a level behavior of sensed image data X(n) handled by a W data generator 7 from sensed data x(n) that is output from a sweep memory 4. Previous behavior data constituted by level detection data of several past scans is stored in a behavior data memory 12, and the behavior detector 11 updates the previous behavior data with the current level detection data and outputs the result to the W data generator 7. Detecting characteristics of the sensed image data of corresponding pixels from the behavior data, the W data generator 7 selects filter calculation data W(n), the current sensed image data X(n) or specific filter calculation data Z(n) and outputs the selected result as written image data Y(n).

Abstract: A method and apparatus for processing signal pulses received by a device to identify the presence or absence of a waveform is provided. The waveform may have a long duration and may have a sparse energy distribution. An example of such a waveform is the bin-5 radar waveform. Based on the arrival rate of pulses, filtering of pulses is performed. The pulses that are not filtered out are grouped into bursts and information about the bursts is stored in a burst history. For example, the burst history might store the number of pulses in the burst and an inter-burst interval time. Entries over a certain age may be deleted from the burst history. The burst history is analyzed to determine if the pulses conform to a pattern associated with the waveform. The analysis may be based on various statistics. In an embodiment, only time domain information is analyzed.

Abstract: A method and system for using a single transceiver to correlate radar position data with target identification data. Two transceivers, operating in round trip delay mode, can be used to provide two possible positions for a given target when radar coverage is lost or unavailable. Three transceivers can be used to provide actual position of a given target using round trip delay data only.

Abstract: A sequence of waveforms is generated by producing a primary symbol sequence and, for each symbol within the sequence, substituting a randomly-selected waveform. The primary symbol sequence has a narrow autocorrelation function, and may be a train of pulses, with the pulses arranged in packets of predetermined configuration. Objects can be detected by transmitting the waveforms, forming a representation of the transmitted waveform and delaying that representation, and correlating the representation with signals received as a result of reflection of the transmitted waveforms.

Abstract: A spread spectrum radar performs a target detection process in a first mode. The target detection process includes performing a slide unit detection a plurality of times while sliding transmission code by predetermined number of chips. The slide unit detection includes transmitting the transmission code and performing a sliding-correlation calculation between the transmission code and a reception code. A method for evaluating the spread spectrum radar includes when the spread spectrum radar is changed to a second mode, which is different from the first mode, stopping the slide unit detection to be performed subsequently to the slide unit detection being performed at a time of changing to the second mode; and transferring a data group that indicates sliding correlation values obtained in the slide unit detection being performed at the time of changing to the second mode.

Abstract: Systems and methods for terrain contour matching navigation are provided. In one embodiment, a method for terrain contour matching navigation comprises: receiving at least one sample point representing the position of an aircraft, the at least one sample point including a horizontal position and an altitude sample; correlating a first sample point of the at least one sample point across a reference basket array having a plurality of elements; determining a correlation quality; when the correlation quality does not achieve a pre-determined quality threshold, performing at least one additional correlation of an additional sample point of the at least one sample point across the reference basket array; and when the correlation quality does achieve a pre-determined quality threshold, calculating a position error based on the correlating of the first sample point and any additional correlations of any additional sample points.

Abstract: A transmitter for transmitting signals to targets and a receiver for receiving signals reflected from targets are included. The transmitter outputs CW signals for detecting direction and velocity of the target. The receiver performs: a function of receiving signals reflected from targets with a plurality of receiving antennas at the same time as transmitting from the transmitter, and performing spectral analysis with respect to receiving signals to thereby classify them by velocity component; a function of correlating signals of the receiving antenna systems; a function of integrating the signals correlation-processed; and a function of obtaining phase fronts of signals made incident on an antenna face from the phase differences of signals between receiving antennas, and performing two-dimensional FFT to the outputs to thereby measure the direction and velocity of the target.

Abstract: There are provided a differential processing unit which performs differential processing for a Mode S transponder transmission signal, an auto correlation arithmetic operation unit which performs an arithmetic operation of a degree of auto correlation between an increasing change rate and decreasing change rate of a power level in the signal which has been subjected to the differential processing, a pulse regeneration unit which regenerates a pulse based on the degree of auto correlation, which has been obtained by the auto correlation arithmetic operation processing, a pulse phase locked loop unit which performs gate processing and phase locked processing for the regenerated pulse, and a pulse decoding unit which decodes the Mode S transponder transmission signal based on the pulse which has been subjected to the gate processing and the phase locked processing.

Abstract: A method and apparatus are disclosed for forming an image from millimeter waves. A field of view scanned using two geometrically orthogonal, intersecting copolarized fan beams (110, 120) to receive millimeter wave radiation. The received millimeter wave radiation from said fan beams are then cross-correlated (250, 650). Also, a method and antenna (400, 610) for receiving millimeter wave radiation are disclosed. The antenna includes first and second fan beam antennas (410, 420) for receiving millimeter wave radiation and a filter (430, 440) for rotating polarization of incident millimeter wave radiation through 90 degrees received by the second fan beam antenna (410). The respective first and second beams (110, 120) intersect and are co-polarized and geometrically orthogonal to each other.

Abstract: The invention concerns a method and apparatus for estimating a height of a target object using radar signals reflected from the target object wherein a receiver detects a plurality of radar signals reflected from the target object, respectively, at a plurality of different ranges, resolves the amplitudes of the plurality of reflected signals at the respective plurality of different ranges to generate an amplitude data set, and determining if the amplitude data set correlates to a particular height.

Abstract: An object detection system is provided with radar detection means (2), image detection means (3), and collating means (4).

Abstract: A method and apparatus is provided, whereby a scanning, polarization and frequency diverse radar system measures the complete polarimetric characterization of weather targets without loss of scanning speed and without an additional ambiguity in the Doppler velocity beyond that given by Nyquist's sampling theorem. In one embodiment, a linear combination of a horizontally and a vertically polarized signal are transmitted at a predetermined first frequency. Cotemporaneously or nearly cotemporaneously with the transmitted signal of the first frequency, a horizontally polarized signal is transmitted at a predetermined second frequency. Horizontal and vertical receive channels receive echoes at the predetermined first frequency to determine, but not limited to determine, the co-polar elements of the scattering matrix. Horizontal and vertical receive channels receive echoes at the predetermined second frequency to determine, but not limited to determine, the cross-polar elements of the polarization matrix.

Abstract: A real-time signal processing engine robustly detects, localizes, tracks and classifies ground targets based on radar signals from a multistatic radar system. The system differentiates between different targets based on an optimized cost function, which can include the total returned normalized pulse energy. The local transmitters/receivers can communicate with each other via the transmitted radar signals.

Abstract: Methods and apparatuses for target radial extent determination using deconvolution are presented. One embodiment features a method for determining a radial extent of an target using an active sensor performing noise reduction on a received signal, deconvolving the noise reduced received signal by a transmit signal to produce a target profile, where both the noise reduced received signal and the transmit signal are over-sampled, and determining the target radial extent using the target profile. Another embodiment further features transforming the digitized transmit signal, transforming the digitized receive signal, thresholding the transformed digitized receive signal, dividing the noise reduced, transformed digitized receive signal by the transformed digitized transmit signal, and inverse transforming the divided signal.

Abstract: An electronic scanning radar apparatus has a cutting portion for cutting receiving data which is comprised of N numbers of data for each channel into two more short time data having M (<N) numbers of data in a time direction for each channel, an inverse matrix estimator for computing and estimating an inverse matrix of the time series correlation matrix from the short time data, and a phase information producing portion for computing CAPON phase information out of the estimated inverse matrix of the time series correlation matrix in order to detect a distance, an azimuth and a relative speed of a target on the basis o a computed CAPON phase information.

Abstract: Signal processing with reduced combinatorial complexity for tracking evolving phenomena such as radar tracks associated with weighted measurement parameters includes selecting a current phenomenon and obtaining a set of measurement parameters associated with it. Beginning at a start node providing a first parent node having an identity, an identity for a child node of the patent is produced from the sets of parameters, the parent identity and a parameter selected from the set and corresponding to the child. This is iterated for other parameters in the set. Child nodes of like identity for the phenomenon are treated as a single node with multiple parameter relationships associated with at lest one parent node, whereas child nodes with differing identities are represented as separate nodes. The process is iterated for other phenomena and associated sets of measurement parameters, but child nodes of a previously processed phenomenon are not treated as parent nodes of a phenomenon processed immediately following.

Abstract: An adaptive waveform radar system transmits a selected waveform of a family of related waveforms and either phase shifts or bit shifts the radar return signal for correlating with the other waveforms of the family. In some embodiments, phase shifting may be performed to null an unwanted target or clutter, while bit shifting may be performed to enhance a desired target, although the scope of the invention is not limited in this respect. In some embodiments, the bits of the return signal may be either phase shifted or bit shifted to match a bit of each one of the other waveforms of the family prior to correlation.

Abstract: Apparatus and a method utilizing correlation interferometer direction finding for determining the azimuth and elevation to an aircraft at long range and flying at low altitudes above water with a transmitting radar while resolving multipath signals. The signals from the radar are received both directly and reflected from the surface of the water using horizontally polarized and vertically polarized antenna arrays, are digitized and are stored in separate covariant matrices. Eigenvalues for the eigenvectors of the matrices processed on signal samples recorded on horizontally polarized X arrays are compared to the eigenvalues for the eigenvectors of the covariance matrices processed on signal samples recorded on vertically polarized X arrays. Incident field polarization is associated with the antenna array measurements that yield the strongest eigenvalue. The eigenvector and eigenvalues for the strongest signal are selected and used for subsequent signal processing.

Abstract: A radar classifies an unknown target illuminated with a large bandwidth pulse. The large bandwidth pulse may be algorithmically synthesized. The target reflects the large bandwidth pulse to form a return. The return is digitized into digital samples at range bin intervals. A computer extracts unknown range and amplitude pairs descriptive of the unknown target from the digital samples. Some range and amplitude pairs are located within one range bin interval. Principle scatterers are extracted from the unknown range and amplitude pairs using Modified Forward backward linear Prediction to form an unknown feature vector for the target. A plurality of pre-stored, known feature vectors containing known range and amplitude pairs are retrieved from the computer. The known range and amplitude pairs are descriptive of known targets, and are grouped in clusters having least dispersion for each of the known targets.

Abstract: A single transmit multi-receiver modulation radar modulates radar return signals received through an associated receive-signal path with one of a plurality of differing modulation waveforms having low-cross correlation products. Each receive-signal path may be associated with a different receive direction. The differently modulated return signals from each receive-signal path may be combined and correlations may be performed on the combined and differently modulated radar return signals using the modulation waveforms to locate a target. In some embodiments, the trajectory of the target may be extrapolated and the target's source location may be determined.

Abstract: A method and system for using a single transceiver to correlate radar position data with target identification data. Two transceivers, operating in round trip delay mode, can be used to provide two possible positions for a given target when radar coverage is lost or unavailable. Three transceivers can be used to provide actual position of a given target using round trip delay data only.

Abstract: The invention relates to a method for the observation of a number of objects, which move in a space monitored by a number of sensors, are recorded by the sensors and followed with continuous updating of at least the sensor track defining the kinematics of the object, whereby those provided sensor tracks amongst the sensor tracks from various sensors, which correspond to the same object are automatically assigned to a system track. In order to improve the method with regard to an efficient assignment of the sensor tracks, which is reliable, has a reduced error probability and runs essentially automatically, an assignment of a sensor track to at least one system track is always carried out if a decision on the non-correspondence to the system track can not be securely taken. Subsequently, assigned sensor tracks are continuously monitored for the continued assignment thereof to the assigned system track and on determining the non-correspondence thereof, are removed from said system track.

Abstract: A transmitter emits into an intended search space a radar wave having a predetermined frequency pulse-modulated by a trigger pulse of a predetermined width. A receiver receives a reflected wave of the radar wave and outputs a receive signal. A local pulse generator outputs a local pulse signal having the predetermined frequency pulse-modulated by the trigger pulse delayed by the delay unit. A correlation value detector detects a strength correlation value between the receive signal and the local pulse signal. A delay time changing unit changes the delay time sequentially within a range of a predetermined period representing a generation period of the trigger pulse. A correlation value storage unit stores the strength correlation value detected for each delay time changed. A frequency distribution generator generates a frequency distribution of a stored correlation value against the delay time.

Abstract: Unknown alignment biases of sensors of a tracking system are estimated by an iterative Kalman filter method. Current measurements are corrected for known alignment errors and previously estimated alignment biases. The filter time reference is updated to produce estimated target state derivative vectors. A Jacobian of the state dynamics equation is determined, which provides for observability into the sensor alignment bias through gravitational and coriolis forces. The target state transition matrix and the target error covariance matrix are propagated. When a new measurement becomes available, the Kalman gain matrix is determined, the state vector and covariance measurements are updated, and sensor alignment biases are estimated. The state vector, covariance measurements, and estimated sensor alignment biases are transformed to an estimated stable space frame for use in tracking the target and updating the next iteration.

Abstract: A method is disclosed of generating multi-resolution images using synthetic aperture radar (SAR) phase history data. A high resolution SAR image may be formed from the phase history data, or a lower resolution SAR image may be formed from a sub-aperture of the phase history data. The multi-resolution images may also be compressed. Compressed multi-resolution images are progressively transmitted to a client until the client receives an image with adequate image quality and/or resolution. Compressed multi-resolution images may also be used for iterative target detection, where images are analyzed by a target detection processor, starting with a lowest resolution image, going to a highest resolution image, until an adequate image of the target or scene is obtained. If a target is not found in the multi-resolution images, a new sub-aperture is chosen on the phase history data, and the target detection process repeats for the new sub-aperture.

Abstract: A system for obtaining frequency domain interferometric super-resolution of a target scatterer, having a first and a second coherent transceivers, a mutual coherent sub-system and an estimation system. The first and second coherent transceivers are operative to produce a plurality of first and second sampling signals separated from each other by a predetermined frequency difference within the first and second sub-band, respectively. The mutual coherent sub-system is coupled to the first and second coherent transceivers to receive phase and amplitude of the first and second sampling signals, so as to evaluate an ambiguous range estimate from a pair of the first and second sampling signals and an unambiguous range estimate from a pair of the first and/or second sampling signals.

Abstract: A radar apparatus calculates distances or relative speeds of a target according to a plurality of formulae. An predicted distance calculation formula is obtained at the following observation from the distances or the relative speeds thus calculated. A determination is made as to whether the distance calculation formula at the current observation is equal to the predicted distance calculation formula, and only when they are equal to each other, the result of the calculation is output. A distance, a relative speed and a distance calculation formula at the following observation are calculated, and a determination is made as to whether there is a correlation between the result at the current observation and the result of the prediction section. Only the result of the calculation at the current time point is output in the presence of a correlation.

Abstract: A radar on a moving platform for three dimensional target recognition of a target on a flat or sloping terrain is described. The target is illuminated from a plurality of locations to generate images at many aspect angles. The radar is positioned at a low grazing angle with respect to the target for generating a shadow of the target on the flat or sloping terrain for each aspect angle of the plurality of aspect angles. The radar comprises an analog to digital converter for converting reflections from the target induced by radar illumination into target digital data and for converting reflections induced by the illumination from the flat or sloping terrain into terrain digital data.

Abstract: A radar equipment of the present invention amplifies a reception signal with feedback based on the delay amount obtained from the correlation detection result. Accordingly, it becomes possible to maintain the reception signal (demodulated signal) level to a proper level depending on the distance to the target, and accurate measurement can be achieved with high precision. Namely, the reception signal is amplified depending on the distance to the target, and the reception signal level is made within a tolerable input level range of a logic circuit for performing correlation calculation. In particular, during tracking the target, even when a reflected signal is received with abrupt level variation caused by noise or a reflected signal from an object other than the target, incorrect detection of the target can be avoided by disabling the correlation calculation.

Abstract: A real-time signal processing engine robustly detects, localizes, tracks and classifies ground targets based on radar signals from a multistatic radar system. The system differentiates between different targets based on an optimized cost function, which can include the total returned normalized pulse energy. The local transmitters/receivers can communicate with each other via the transmitted radar signals.

Abstract: An imaging apparatus has transmitter illuminating a selected surface with a radar beam footprint, and processor for profiling/processing the radar returns so as to derive attitude information in real time about a number of predefined axes associated with the radar which depends upon the relative dispositions of the radar, the selected surface and upon the radar beam footprint characteristics. A plurality of transmit beams image the surface and the processing arrangement has the capability of determining roll, pitch and/or yaw pointing data associated with the radar, such pointing data being determined by derivation of the attitude information and by selective input of terrain elevation data so as to take account of variations in the radar viewing geometry with terrain elevation. This provides a low cost advantage over known radar designs, and retains utility for many applications, for example spaceborne and airborne applications.

Abstract: Tracking objects by receiving a dataframe from a detection sensor device, the dataframe containing a timestamp and data corresponding to each detected object, generating new observation nodes for each detected object, propagating group track state parameters to obtain posterior observable positions and projecting them onto the received dataframe, generating gates for the posterior observable positions and projecting them onto the received dataframe, determining feasible track node and feasible observation node assignments based on the proximity of the new observation nodes to the gates, updating track node state parameters and corresponding scores, performing a multi-frame resolution algorithm to resolve group track nodes into subtrack nodes, determining a set of feasible composite assignments for composite sets of track nodes and observation nodes, updating track node state parameters and corresponding scores, and determining a selected set of joint assignments based on the feasible composite assignments and

Abstract: A system and technique for calibrating a plurality of radars provides a set of simultaneous equations derived from monostatic echo returns from a plurality of targets. A solution of the simultaneous equations provides relative position calibration factors and time delay calibration factors associated with the plurality of radars. The relative position calibration factors and the time delay calibration factors allow the plurality of radars to be coherently combined with only a small amount of processing gain loss compared with an ideal coherent processing gain.

Abstract: An antenna system for a computing device operable in multiple communication modes.

Abstract: Method and apparatus for detecting objects. In one embodiment, a person entering a secured zone is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected. Concealed weapons are detected by measuring various parameters of the reflected signals and then calculating various selected differences between them. These differences create patterns when plotted as a function of time. Preferably a trained neural network pattern recognition program is then used to evaluate these patterns and autonomously render a decision on the presence of a weapon.

Abstract: The invention is process for tracking a moving targeted vehicle from a remote sensor platform comprising the steps of 1) tracking the targeted vehicle and periodically recording its radar signature until its identity becomes ambiguous, 2) tracking the target after it has left its ambiguous state and periodically recording its radar signature; and 3) comparing the recorded radar signatures prior to the targeted vehicle becoming ambiguous to the recorded radar signature taken after the targeted vehicle has left its ambiguous state and determining that the targeted vehicle now tracked is the same as the targeted vehicle being tracked prior to becoming ambiguous.

Abstract: A transmitted signal and a received signal are combined and the combination is expected to determine whether or not a target signal is present. Either the transmitted signal or the received signal is combined with an auxiliary signal containing a range of frequencies corresponding to an anticipated Doppler shift, so that an output of the combined transmitted and received signal will be present only if a target signal exhibiting a Doppler shift within the anticipated range is present. The auxiliary signal preferably comprises finite-duration signal portions of different types so as to provide a substantially uniform frequency response throughout the selected range.

Abstract: In some pseudo-orthogonal waveform embodiments, a radar system transmits pseudo-orthogonal waveforms and performs multiple correlations on a combined single receiver channel signal. In some quadratic polyphase waveform embodiments, a radar system may simultaneously transmit frequency separated versions of a single quadratic polyphase waveform on a plurality of transmit antennas, combine the return signal from each antenna into a combined time-domain signal, and perform a Fourier transformation on the combined time-domain signal to locate a target. The radar system may identify a target, such as sniper's bullet, incoming projectile, rocket-propelled grenade (RPG) or a mortar shell. In some embodiments, the system may estimate the target's trajectory to intercept the target. In some embodiments, the system may estimate the target's trajectory and may further extrapolate the target's trajectory to locate the target's source, such as the sniper.

Abstract: A radar system having a beamless emission signature is described. In one implementation, the radar system includes a transmission system and a receiver system. The transmission system is configured to transmit a pattern comprising a plurality of radar signals having different frequencies simultaneously. The receiver system is configured to receive a reflection of the pattern and combine the plurality of radar signals into a composite waveform forming an image of a target.