Abstract: A path in three-dimensions for an object in flight is determined according to a radar signal reflected by the object. The radar signal is transmitted at an offset angle from horizontal sufficient to capture the object within the transmitted radar signal. The transmitted radar signal is reflected by the object to form a reflected radar signal containing an indication of a position of the object. The reflected radar signal is received and used to determine two-dimensional position information for the object by detection of the indication of the position of the object in the received radar signal. Position information is derived in three-dimensions from the position information in two-dimensions. The path information representative of the path for the object is obtained from the position information in three-dimensions based on an optimization of a curvature of said path information.

Abstract: If the maximum time width Lt of the intensity of received light of reflected waves from a vehicle ahead is smaller than a reference time width, it is judged that the vehicle ahead is positioned in proximity to the detection limit distance of an obstacle detection device for vehicle. Thus, there is no problem, for example, even if a cut-in vehicle is present in reality between the vehicle ahead and the vehicle of interest and nevertheless, the distance to the cut-in vehicle cannot be detected. It can be judged whether the vehicle ahead is positioned in proximity to the detection limit distance of the device by judging the magnitude relation between Lt and the reference time width. As a result, the detecting capability of the device can be judged with accuracy.

Abstract: In a system, a frequency-modulating unit is configured to frequency-modulate a radar wave signal within a predetermined frequency modulation range from bottom to top so that a frequency of the frequency-modulated radar wave changes in time. The rate of frequency change of the radar wave signal in time is set to F0/Tf. The F0 represents a center frequency in the frequency modulation range. The Tf represents the predetermined constant time. A mixing unit is configured to mix the transmitted frequency-modulated radar wave signal and the reflection signal to obtain a beat signal. The beat signal is based on a frequency difference between a frequency of the transmitted radar wave signal and that of the reflection signal. A sweeping unit is configured to sweep the beat signal within the frequency modulation range from one of the bottom and the top to the other thereof to obtain a frequency component of the beat signal.

Abstract: A method and apparatus for guiding a vehicle to intercept a target is described. The method iteratively estimates a time-to-go until target intercept and modifies an acceleration command based upon the revised time-to-go estimate. The time-to-go estimate depends upon the position, the velocity, and the actual or real time acceleration of both the vehicle and the target. By more accurately estimating the time-to-go, the method is especially useful for applications employing a warhead designed to detonate in close proximity to the target. The method may also be used in vehicle accident avoidance and vehicle guidance applications.

Abstract: A multi-stage maximum likelihood target estimator for use with radar and sonar systems is provided. The estimator is a software implemented algorithm having four computational stages. The first stage provides angle smoothing for data endpoints thereby reducing angle errors associated with tie-down times. The second stage performs a coarse grid search to obtain the initial approximate target state to be used as a starting point for stages 3 and 4. The third stage is an endpoint Gauss-Newton type maximum likelihood target estimate which determines target range along two time lines. The final refinement of the target state is obtained by the fourth stage which is a Cartesian coordinate maximum likelihood target estimate. The four-stage processing allows the use of target historic data while reducing processing time and computation power requirement.

Abstract: Techniques for analog processing of high time-bandwidth-product (TBP) signals use a material with an inhomogeneously broadened absorption spectrum including multiple homogeneously broadened absorption lines. A first set of signals on optical carriers interact in the material during a time on the order of a phase coherence time of the homogeneously broadened absorption lines to record an analog interaction absorption spectrum. Within a time on the order of a population recovery time for a population of optical absorbers it the material, the interaction absorption spectrum in the material is read to produce a digital readout signal. The readout signal represents a temporal map of the interaction absorption spectrum, and includes frequency components that relate to a processing result of processing the first set of signals. The techniques allow processing of RADAR signals for improved range resolution to a target, as well as speed of the target, among other uses.

Abstract: A radar system having a processor, a waveform generator, a plurality of antenna interfaces, a set of first antennas configured to transmit a waveform, and a set of second antennas configured to receive a reflected waveform is disclosed. The waveform generator and antenna interfaces are in control and signal communication with the processor, each of the first antennas are in signal communication with one of each antenna interface, and each of the second antennas are in signal communication with one of each antenna interface. The waveform generator is in control and signal communication with each antenna interface, and is configurable to generate a waveform conforming to at least two ISM bands. Each first antenna is configured to transmit a circularly polarized electromagnetic waveform, and each second antenna is configured to receive a reflected circularly polarized electromagnetic waveform complementary to the first antennas.

Abstract: A method of detecting radar returns and measuring their parameters with or without clutter present and no clutter cancellation employed which includes transmitting at least one pulse; processing the returns surpassing a threshold detected in one range azimuth bin and by processing and separating out the returns based on their different range and azimuth. Another method includes transmission of many pulses and has minimum of one channel return surpassing detected threshold, which is detected in one range Doppler bin. The method also includes processing and thereby separating out the returns based on their different radial velocity and or azimuth and comparing the returns to a database of expected returns and adaptively processing returns that do not correspond to the expected returns. The method identifies the non-corresponding returns as indicative of at least one of clutter, land sea interface, clutter discretes and antenna sidelobe returns each without utilizing clutter cancellation.

Abstract: A vehicle control apparatus includes an obstruction detection unit for measuring a headway distance until an obstruction existing ahead of the vehicle by means of a radar device, a unit for performing vehicle control or alarm control on the basis of the headway distance, a unit for detecting detection performance of the obstruction detection means in a vehicle in which the obstruction detection unit is used to perform two or more controls containing the vehicle control or alarm control, and a unit for controlling to stop operation of the vehicle control or alarm control in accordance with the detection performance individually.

Abstract: Described herein is an implementation of the IRAMS processing based upon a multi-delay-resolution framework applied to SAR image data measured at different aspect angles. The power of this new embodiment of IRAMS is that it produces a good separation of immediate response scatterer and delayed response scatterer data for the case of anisotropic scattering events, i.e., those in which the scattering intensity depends upon the aspect angle. Two sources of delayed response scattering include multiple reflection scattering events and delayed responses arising from the physical material composition of the scatterer. That is, this multi-delay-resolution IRAMS processing separates immediate response and delayed response scattering for cases in which there exist delayed response scattering data in the original SAR image data at some aspect angles, but the intensity of these delayed response scattering data is weak or non-existent at different aspect angles.

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: The present invention relates to an avoidance system and method for directing an aircraft away from an exclusion zone. The exclusion zone may be any three dimensional space for example about a building or city. The avoidance system uses a constant signal from a ground based transmitter and an aircraft's receiver which receives and processes the signal and activates the avoidance system by engaging the flight director system or autopilot to steer away from the exclusion zone.

Abstract: A signal transformation apparatus capable of performing stable transformation of a signal using a Mechanical switch includes a signal generator which generates a reserve pulse signal in response to an applied sync signal, a signal controller which outputs control signals to change and transform the reserve pulse signal to pulse signals having a predetermined pulse width, and a signal modulator which transforms the reserve pulse signal to the pulse signals having different pulse widths in response to the control signals. The signal modulator includes a switch bank in which a plurality of mechanical switches are connected in parallel, and a transmission line between nodes where the mechanical switches are formed.

Abstract: Disclosed are a system, method, and program storage device implementing the method, of data fusion, wherein the method comprises determining pre-launch data affecting a flight of a self-sensing air-bursting ballistic projectile, the projectile comprising a plurality of independent data sensors; predicting a trajectory path of the projectile based on a target location of the projectile; calculating trajectory path errors based on the predicted trajectory path; generating in-flight data from each of the data sensors; combining the in-flight data into a single time-series output using a fusion filter; tracking a trajectory position of the projectile based on the single time-series output, pre-launch data, and the trajectory path errors; comparing the tracked trajectory path with the predicted trajectory path; analyzing the in-flight data to gauge successful navigation of the projectile to the target location; and self-guiding the projectile to the target location based on the trajectory position.

Abstract: A radar system and method for detecting targets using pulse-compressed signals is disclosed. In one application, the systems and methods can be used to detect one or more relatively small targets whose pulse-compressed signals are masked by the time-sidelobes of a larger target's return signal. The method includes an iterative, detect-and-subtract signal algorithm that processes the post-compressed signal to detect multiple targets. Specifically the processing algorithm operates on the post-compressed signal to identify a point spread function (PSF) that corresponds to the relatively large target. Once identified, the PSF corresponding to the largest target in the post-compressed signal is subtracted from the post-compressed signal to generate a residual signal. This residual signal, in turn, includes the PSFs for the other targets. This process of identifying and subtracting the PSF of the largest target in the residual signal is then repeated until all targets are detected.

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 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: In a method for determining the distance between two transmitting and receiving stations, a transmission signal is generated in each station and is transmitted as a series of microwave pulses having a predefined pulse repetition frequency to the other respective station. The coincidence of pulses of the transmission signal sent by the respective station and the signal received by the station is detected in each station as a coincidence event, and the number of pulses transmitted and received by the respective station at the time of the coincidence event is determined. The distance between the stations is then calculated on the basis of the number of the determined pulses.

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 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: The number of power amplifiers required to amplify a plurality of transmission signals is reduced by using non-linear transmission lines (NTL) circuits. In general, a “combining” NTL circuit is used to combine the plurality of transmission signals to form a soliton pulse. The soliton pulse is then amplified such that each of its component transmission signals are amplified. A “dividing” NTL circuit is then used to divide the amplified soliton pulse into its component amplified transmission signals. The amplified transmission signals can therefore be transmitted over a communications channel without requiring a separate power amplifier for each.

Abstract: The present invention provides a radar altimeter system with a closed loop modulation for generating more accurate radar altimeter values. The system includes an antenna, a circulator, a receiver, and a transmitter. The circulator receives or sends a radar signal from/to the antenna. The receiver receives the received radar signal via the circulator. The transmitter generates a radar signal and includes a phase-locked loop circuit for generating the radar signal based on a pre-defined phase signal. The transmitter includes a direct digital synthesizer that generates the phase signal based on a pre-defined clock signal and a control signal. The system includes a digital signal processor and a tail strike warning processor that determine position of a tail of the aircraft relative to ground and present an alert if a warning condition exists based on the determined position of the tail of the aircraft and a predefined threshold.

Abstract: The present information comprises the stages of: applying frequency analysis to positional information on a platform, generating virtual positional information on the platform based on a frequency analysis result; extracting a signal based on the generated virtual positional information; and performing a synthetic aperture processing based on the extracted signal, and in this manner, even if the positional information lacking in precision and inaccurate is used, the shake compensation of the platform in the synthetic aperture processing system can be effectively performed.

Abstract: A method is disclosed for evaluating the terrain surrounding a radar site. The method comprises to calculate the radar horizon around a radar site from stored terrain elevation information. The information obtained can be used for controlling the scanning profile of the radar, by letting the radar scan above the calculated horizon, and thus avoiding transmitting into the terrain.

Abstract: Disclosed herein is a computer-readable medium having stored thereon computer-executable instructions for providing phase-range data associated with a return pulse of a radar device and second phase-range data associated with a successive return pulse of the radar device. The computer-executable instructions are preferably also for comparing the phase-range data and the second phase-range data to obtain a difference, and for differentiating the difference. In some embodiments of the invention, the computer-executable instructions are preferably also for discriminating a target from clutter by using the differentiated difference to identify coordinates satisfying a velocity threshold associated with the clutter. Embodiments of the invention preferably enable phase-coherent operation of a non-coherent radar device by processing backscattered clutter return, and in some aspects, do so using clutter distributed in range as a reference.

Abstract: A method for reducing angular blur in radar pictures achieved in range bin based detection systems includes measuring a variable S(x, y) such as amplitude or power as a function of an angle x and a distance y. An expression: corrected angular position=angular position+angle correction is determined in each range bin for a plurality of angular values x. The term “angle correction” includes derivative(s) of first or higher order of the variable S(x). The variable measured at the angular position “angular position” is moved to the variable in the angular position “corrected angular position”, and the moved variable and the variable in “corrected angular position” are processed by adding or maximizing the values.

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. Multiple receiver hardware configurations may be available for detecting a set of emitters. A system and method are provided that allow an operator to select the most appropriate configuration for an intercepting dwell, thereby facilitating resolution of conflicting hardware configurations for different emitter modes.

Abstract: A microwave system is capable of inspecting a medium, especially capable of inspecting food products transferred by a conveyer belt in real time. The microwave system includes a transmitter for transmitting continuous microwave; a receiver for receiving the microwave passing through the medium; a scanner for electrically directing a microwave beam along a linear path, especially, across the conveyer belt; a waveform extractor for extracting the informational parts of the received signal outputted by the receiver; and a cpu for analyzing the data outputted by waveform extracting means.

Abstract: A method for radar protection. The method includes recording energy events and calculating differences in recorded energy events to determine pulses. The method further includes sorting intervals between pulses into histogram bins, each bin representing a range of time intervals between two pulses, each pulse indicative of a radar frequency and limiting network traffic on a frequency based on a selected bin count.

Abstract: The object of the present invention is intended to solve the problem of the broadcasting of conditional access data where certain parts must be accessible either for technical reasons or for commercial reasons.

Abstract: The present invention provides an electric wave axis adjusting apparatus for an on-vehicle radar capable of readily and precisely adjusting an electric wave axis only by making the scanning range and a detection range identical to each other and changing a scanning range, and of adjusting the electric wave axis of an on-vehicle radar without wasting time in order to detect a reflector.

Abstract: A target identification and tracking system includes a carrier vehicle and one or more tracking vehicles. The carrier vehicle may determine an aimpoint of a target from a high resolution image of the target and may generate an offset from a tracking point to the aimpoint. The offset may be conveyed to an assigned tracking vehicle for tracking the tracking point of the target while navigating toward the aimpoint of the target. The tracking point may be the target's centroid. The carrier vehicle may employ a high-resolution LIDAR imaging system to identify the aimpoint from a target's features; while the tracking vehicle may employ a lower resolution optical imaging system for tracking the target's tracking point. The carrier vehicle may correct the offset for parallax and the offset may be revised as the tracking vehicle approaches the target.

Abstract: System and method for detection and tracking of targets, which in a preferred embodiment is based on the use of fractional Fourier transformation of time-domain signals to compute projections of the auto and cross ambiguity functions along arbitrary line segments. The efficient computational algorithms of the preferred embodiment are used to detect the position and estimate the velocity of signals, such as those encountered by active or passive sensor systems. Various applications of the proposed algorithm in the analysis of time-frequency domain signals are also disclosed.

Abstract: A technique for boresighting an antenna mounted on a moving platform is described. The technique uses a concurrently moving calibration target. Target navigation data and platform navigation data are used to compensate for movement of the target and the platform. The antenna pointing direction is biased in a direction which provides a best signal quality, and the bias used to determine antenna boresight calibration factors. The boresight correction factors can be used for open loop pointing.

Abstract: A method for detecting radar is provided by the present invention. The invention begins by sweeping a first local oscillator (LO). Once a band has been identified as containing a radar signal, the detector interrupts its normal operation and rechecks the frequency in question for confirmation of CW radar, rather than waiting for the initial sweep to finish. Upon receiving partial information from the initial fast sweep, the detector may repeat this sweep at a slower rate in order to improve sensitivity towards a CW source. If information was from a CW source one can be assured to see the information again when sweeping the same frequency. By contrast, if initial information is from a swept radar detector the information will not be present in the rescan, as the offending radar detector would have moved to a different frequency during the same period of time.

Abstract: A synthetic aperture radar (SAR) system having a single phase center antenna is provided, the SAR system including a measurement unit and a tracker unit. The measurement unit is capable of receiving a phase history of a target point scatterer. From the phase history, then, the measurement unit is capable of estimating a ground position, velocity and acceleration of the target to thereby detect the target. The tracker unit, in turn, is capable of updating the ground position, velocity and acceleration of the target to thereby track the target based upon the ground position, velocity and acceleration. In this regard, the tracker unit is capable of updating the ground position, velocity and acceleration using a Kalman filter.

Abstract: The present invention provides that a monopulse radar system to correct an amplitude error and a phase error developed between receiving channels and improve the accuracy of a detected angle. A part of a transmit signal is supplied to respective channels on the receiving side through a signal transmission line for calibration. At this time, the gains of a variable phase shifter and a variable gain amplifier are adjusted so that an azimuth angle of a pseudo target, based on a signal for calibration, which is calculated by signal processing means, reaches a predetermined angle. In the monopulse radar system of the present invention, calibration work is simplified and an angular correction can be automated. The present monopulse radar system of the present invention is capable of coping even with variations in characteristic after product shipment due to environmental variations and time variations in parts characteristic.

Abstract: The invention relates to a method for determining the filling level of a medium in a container. A mixer that has at least one mixer blade and a mixer frequency (f<1>R</1>) is disposed in the container. Measuring signals are emitted at a predetermined measuring frequency (f<1>M</1>) towards the medium. The measuring signals reflected on the surface of the medium are received and evaluated by a run time method. The aim of the invention is to provide a device which allows for a reliable measurement of the filling level of a medium in a container provided with a mixer. To this end, the measuring frequency (f<1>M</1>) of the measuring signal having the mixer frequency (f<1>R</1>) of the mixer is synchronized (f<1>M</1>=n f<1>R</1>with n ? N) and that the measuring frequency (f<1>M</1>) is shifted by a defined phase (?) with respect to the mixer frequency (f<1>R</1>).

Abstract: A system and method for performing distance measurement using wireless signals. A time of flight calculation is enabled by an interrogating device that transmits an interrogation signal to a responding device, which returns a synchronized signal back to the interrogating device. The wireless signals between the interrogating device and the receiving device have a harmonic relationship. In one embodiment, a time shift of a received signal relative to a transmitted interrogation signal is determined based on a comparison of a first reference point on a signal representative of the transmitted interrogation signal and a second reference point on a signal representative of the received signal.

Abstract: A multistatic radar has a radar transmitter for illuminating a target with a radar signal. The target reflects the radar signal to three separate radar receivers, each performing a bistatic range measurement to the target. The three bistatic range measurements are combined in a quadratic equation having two solutions (roots). One solution (root) corresponds to a correct three dimensional target position with respect to the radar transmitter while the other is an incorrect three dimensional target position with respect to the radar transmitter. The incorrect three dimensional target position is identified and eliminated by comparing the three dimensional target position to the transmitter location, and the receiver locations. The incorrect three dimensional target position is also identified by the target altitude exceeding a threshold, typically set above 80,000 feet AGL.

Abstract: An improved system is provided for aiming a shotgun-based or other countermeasure system so as to be able to countermeasure incoming rockets or projectiles. In one embodiment a shotgun aimed and controlled by the subject system projects a pattern of pellets to intercept a rocket-propelled grenade or incoming projectile. The fire control system uses a CW two-tone monopulse radar to derive range and angle of arrival within 150 milliseconds, with range and angle of arrival measurements having approximately twice the accuracy of prior CW two-tone monopulse radars. The improvement derives from using all of the information in the returned radar beams and is the result of the recognition that one can use the Sum and Difference signals to assemble a two-by-two Rank One matrix that permits using singular value decomposition techniques to generate range and angle of arrival matrices in which all available information is used and in which noise is eliminated.

Abstract: The present invention relates to a separable radar detector, and more particularly, to a separable radar detector, wherein a horn antenna and a circuit for detection, and a display unit for displaying detected signals thereon are constructed to be moved, separated or rotated with respect to each other. The separable radar detector of the present invention comprises a horn antenna, a signal-processing unit for processing signals received by the horn antenna, an upper case for accommodating the horn antenna and the signal-processing unit, a lower case connected to the upper case to be relatively moved with respect thereto, and a display unit connected to the signal-processing unit and installed in the lower case to inform a user of the received signals processed by the signal-processing unit.

Abstract: Methods and apparatus are provided for operating a radar system to provide a thunderstorm image to a pilot. The method comprises using one or more radar scans depending upon the aircraft altitude, a single upward tilted scan at or below a datum level of about 15,000±3000 feet wherein a clutter free storm image may be obtained and two scans above the datum level; a first upward tilting scan to determine, clutter free, a storm head perimeter and a second lower tilting scan for the storm body with ground clutter. The perimeter is used to discard return echoes from the second scan that lie outside the perimeter or an expansion thereof and retain those lying on or within the perimeter. The result is presented to the pilot. Optionally, the thunderstorm image is graded from center to edge so as to indicate weaker echo intensity near the edge.

Abstract: A method and an antenna arrangement are disclosed for reducing the antenna radar cross section for an externally illuminating radar source. A radar pulse is transmitted with the antenna arrangement fully matched to achieve a lowest possible power loss of the pulse. At all other times the antenna will be poorly matched and thereby will act as a low radar cross section. The reduced radar cross section leads to an antenna gain reduction, which most often can be accepted since competing noise is reduced as much as the useful signal. It is further suggested that the range gate of the receiver and the transmitter pulse control the antenna. Thus, the antenna is “fully opened” during the transmitting pulse and may be partly or “trade-off” matched during range gate reception. In the interval of not transmitting or receiving, the antenna will present a low radar cross section.

Abstract: A fast acting active protection system for military vehicles defeats RPG (rocket propelled grenade) threats fired from close ranges. The system minimizes the hazard to troops and civilians nearby. The system uses a plurality of passive sensors to locate the threat and initialize the system. A low cost radar or laser tracker is used as the means to determine range, velocity, and (if required) angular position of the threat. The countermunition used may be one of several choices, with the requisites being that the countermunition provides fast response with low inertia, and is able to damage or destroy the detected threat. A multi-barrel recoilless gun is the weapon of choice. A launching device is used to deploy and aim the countermunition and the tracking means. On board software and electronics are used to control the system.

Abstract: A radar system (500) radiates a radar transmit signal, has a radar signal receiver (503) and a canceller (505) for canceling leakage of the transmit signal into the radar signal receiver (503). The canceller (505) comprises a digital waveform generator (528) for generating a first digital signal converted to an analog waveform. The analog waveform is amplified after a fixed delay (534) to generate a first cancellation signal input into a circulator (504). The circulator combines the first cancellation signal with the leakage to generate a first corrected signal. A summer (507) combines the first corrected signal from the circulator with a second cancellation signal to generate a second corrected signal. The second cancellation signal is generated by a digital cancellation filter (526). The digital cancellation filter (526) has as an input the first digital signal from the digital waveform generator (528).

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: An apparatus for estimating direction of arrival of signal is provided that has excellent performance in terms of angular resolution and the number of signals that can be identified. In an array sensor comprising a plurality of sensor elements, the two outermost sensor elements are alternately selected by a switch for use as a transmitting sensor, and the other sensor elements are selected in time division fashion as receiving sensors. With this arrangement, the effective aperture is increased to about twice the physical aperture, to improve angular resolution in a direction-of-arrival estimator.