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: An apparatus for non-coherently detecting slow-moving targets in high resolution sea clutter includes a binary detector for converting high resolution radar returns, produced in response to a radar pulse scan of a plurality of identical pulses, into corresponding binary outputs based on a comparison of range cell magnitudes with a detector threshold. A range extent filter converts these binary outputs into an output indicating the presence or absence of a cluster of the returns that are closely spaced in range, while a third, persistence integration stage determines target range extent persistence over a predetermined time period. A detector stage declares detection of a target based on a comparison of the output of the third stage with a selected threshold.

Abstract: A radar system for motor vehicles, having an antenna, a first processor which is developed to transform signals supplied by the antenna via a primary signal path into a spectrum, and a second processor for the additional evaluation of the spectrum, wherein at least a part of the signals received by the antenna is able to be supplied to the second processor via a redundant signal path while by-passing the first processor, and the second processor, on its part, is designed to transform these signals into a spectrum.

Abstract: Provided is a millimeter-wave transmitting/receiving apparatus of pulse-modulation type in which pulse-modulated millimeter-wave signals for transmission are prevented from being outputted to a reception system due to inner reflection or other causes. Included are: an NRD guide (basic structure) formed of a dielectric line sandwiched between parallel plate conductors; a millimeter-wave signal oscillator; a pulse modulator; a circulator; a transmitting/receiving antenna; and a mixer. At the output end of the mixer is disposed a switching device which interrupts intermediate-frequency signals in an opened state, and, when a millimeter-wave signal for transmission from the pulse modulator enters a non-output state and the condition is stabilized, changes into a closed state to pass intermediate-frequency signals.

Abstract: A new technique for re-computing shading parameters for low sidelobe levels for a radar or sonar system is disclosed. When some of the sensor elements become inoperative, remaining shading parameters are recomputed using a new constraint. This approach leads to an overall gain pattern that is superior compared to the one without re-computing the weights.

Abstract: A method of generating aircraft tactical alerts includes receiving track positions for two aircraft; receiving trajectories and static conformance bounds for the two aircraft; receiving current position for the two aircraft; generating tactical check segments and variable conformance bounds for the two aircraft based on the current position, the static conformance bounds, trajectory, adapted data, and the track positions; and generating a tactical alert if the variable conformance bounds overlap within a specified lookahead time. The variable conformance bounds can be either symmetric or asymmetric about projected tracks. The variable conformance bounds can use step functions, or continuously widening bounds up to the static conformance bounds. The variable conformance bounds can be based on modifying the static conformance bounds in two or three spatial dimensions.

Abstract: A method for transmitting a signal waveform from a transmitter within an adaptive broadcast radar system. In one embodiment, wherein the transmitter comprises at least one sub-aperture, the method includes: generating the signal waveform at the at least one sub-aperture; coding the signal waveform at the at least one sub-aperture, wherein the signal waveform is coded with transmitter data; phase shifting the signal waveform at the at least one sub-aperture; and, transmitting the coded signal waveform from an array element coupled to the sub-aperture according to the phase shifting.

Abstract: A method for obtaining target parameters within an adaptive broadcast radar system. In one embodiment, the method includes: coding information about a signal waveform generated by a transmitter having sub-apertures; receiving a signal at a receiver having sub-apertures corresponding to the sub-apertures of the transmitter, wherein the received signal correlates to the signal waveform; decoding information about the signal waveform from the received signal; and, determining a data quad from the decoded information, wherein the data quad includes degrees of freedom associated with the transmitter.

Abstract: This invention relates to sate estimation after processing measurements with unknown biases that may vary arbitrarily in time within known physical bounds. These biased measurements are obtained from systems characterized by state variables and by multidimensional parameters, for which the latter are also known and may vary arbitrarily in time within known physical bounds. The measurements are processed by a filter using a mean square optimization criterion that accounts for random and biased measurement errors, as well as parameters excursions, to produce estimates of the true states of the system. The estimates are applied to one of (a) making a decision, (b) operating a control system, and (c) controlling a process.

Abstract: A radar acquires a formed SAR image of radar scatterers in an area around a central reference point (CRP). Target(s) are within the area illuminated by the radar. The area covers terrain having a plurality of elevations. The radar is on a moving platform, where the moving platform is moving along an actual path. The actual path is displaced from an ideal SAR image acquisition path. The radar has a computer that divides the digital returns descriptive of the formed SAR image into multiple blocks, such as a first strip and an adjacent strip. The first strip is conveniently chosen, likely to generally align with a part of the area, at a first elevation. An adjacent strip covers a second part of the area at a second elevation. The first strip is overlapping the adjacent strip over an overlap portion. The first and second elevation are extracted from a terrain elevation database (DTED).

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: Apparatus and methods for performing automatic gain control in a radar system. One embodiment of the system includes an attenuator that controls gain of signals received from a radar receiver. A digital signal processor determines coarse gain correction based on digitized noise data for a plurality of channels, determines fine gain correction based on the residual error after the coarse gain, and determines frequency vs. gain curve correction based on the digitized noise data for a plurality of channels and a mathematical model of frequency gain across a noise spectrum for the radar system. The result of the processor is a gain control signal that is sent to the attenuator to perform hardware gain control and a channel specific scale factor for software gain control. In one embodiment, the processor generates the gain control signal during an inactive scan mode of the radar system.

Abstract: Signal processing systems for radar installations are provided for simultaneous processing of one or more IF signals of dynamically varying frequency and bandwidth with a single analog signal path. The signal processing system includes, but is not limited to, a converter configured to digitize a return signal resulting in a digitized broadband signal, and a signal processor coupled to the converter. The signal processor includes a digital filter having a center frequency and a bandwidth, and the digital filter is configured to select a signal from the digitized broadband signal. The selected signal has a center frequency. The signal processor is configured to match the center frequency of the digital filter with the center frequency of the selected signal, and adjust the bandwidth of the digital filter based on the selected signal.

Abstract: A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.

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 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 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 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: 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: 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: 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: 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 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: 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: 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 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: 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 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: 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: 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: 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 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: 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: 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: 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: 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: 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.