Abstract: Apparatus and methods for reducing data flow through a signal processing system are disclosed. A method according to the invention includes receiving a set of tags from an input system, where each tag is associated with a pulse and includes a pulse characterization parameter that characterizes the associated pulse. The pulse characterization parameter can be based on, for example, pulse center frequency, duration, or angle of arrival. The method includes identifying a subset of tags from the set of tags, where each tag in the subset includes a predefined value of the pulse characterization parameter. The subset of tags can be identified by histogramming the set of tags based on the pulse characterization parameter. If the number of tags in the subset exceeds a threshold number, then the number of tags from the subset that is forwarded through the system is limited to no more than the threshold number of tags.

Abstract: A collision warning system (10) discriminates between objects which pose a threat of collision from those which do not by measuring the relative sightline rate of the object, this being a measure of the rate of change of angular position of the object if the sightline rate is above a threshold value, there is little risk of collision. To measure the sightline rate, a radar source (20) emits microwave frequency radiation which is received by two detectors (22 and 24) after reflection from a target. Signals from the detectors are processed by processing means (26). The processing means determines if the sightline rate of an object is below a certain threshold. If it is, and the relative velocities of the object and the system are such that a collision is likely, a warning buzzer (28) sounds.

Abstract: Apparatus and methods for processing RF signals are disclosed. A method according to the invention includes receiving a set of time domain energy samples representing signal energy present in an RF spectrum, transforming the set of time domain energy samples into a set of frequency domain power samples, determining from the set of frequency domain power samples whether a signal of interest is present in the RF spectrum, and forwarding to a follow on system a subset of the set of frequency domain power samples, wherein the subset corresponds to the signal of interest. Transforming the time domain samples can include dividing the set of time domain energy samples into a plurality of N windows, each of which is associated with a predefined window period, and performing an FFT on each said window to generate a set of K frequency bins, wherein each frequency bin has a value based on energy present in a predefined frequency band during the corresponding window period.

Abstract: The invention relates to a radar method for an automatic intelligent traffic control (AICC) in a motor vehicle. The use of a frequency modulation continuous wave method (FM-CM) is suggested in order to securely detect the distance to, relative speed and angle of a preceding motor vehicle. It is furthermore suggested according to the invention that when using an A/D converter 5 with 8-bit resolution, the necessary dynamics are generated by means of a level switchover, that the R, V information is generated in FFTs [Fast Fourier Transformations] 6 with blocked R and V-FFTs, that the useful signals are separated from the noise in a detection device 7 by means of a R-dependent adaptive CFAR threshold, that in a track formation 8, the detection is directly assigned to the tracks and that the association of a detection i to a track j is in the process computed as probability r (i, j).

Abstract: A GPS receiver having multiple GPS antennas. Also described is a method of tracking employing the GPS receiver and a communication transmitter. Also described is a garment having a GPS receiver and a GPS antenna and a communication antenna and a communication transmitter.

Abstract: A radio wave source information display apparatus including: a signal processing circuit having a means for performing the Fourier transform with respect to azimuth of an electric field signal outputted from an antenna receiving circuit, a means for performing the Fourier transform with respect to azimuth of the antenna pattern of an antenna, a means for dividing the Fourier transform signal derived from the electric field signal by the antenna pattern Fourier transform signal, a low-pass filter for subjecting the divided signal to low-pass filtering with respect to azimuthal frequency, a means for extracting exponential function components of the output signal of the low-pass filter, and a means for obtaining radio wave source information from the extracted exponential function components; and a display section for displaying radio wave source information obtained at the signal processing circuit.

Abstract: To calibrate a transmitter and/or sender for controlling a beam forming network, each of the control signals is divided into a plurality of frequency segments. The control signal of each frequency segment is multiplied by complex coefficients so that the transmitter output signals, after passing through a reference receiver, are identical to the respective control signals. A similar adjustment is performed for the receive direction. The method and the device allow the same beam characteristic.

Abstract: A Two-Stage Hybrid algorithm offers significant improvement in the false alarm rate and detection performance of Space-Time Adaptive Processing in non-homogeneous environments for both radar and digital communications. The first stage analyzes data from a range cell of interest by direct data domain processing, suppressing discrete interferers within the range cell of interest. The second stage implements a purely statistical STAP algorithm, preferably an enhanced version of the Joint-Domain Localized (“JDL”) statistical algorithm. For radar this second stage estimates the interference within the range cell of interest from the surrounding range cells. For a communications system, the second stage estimates the covariance matrix of the interference from the entire data block. For both radar and communications, an adaptive filter that suppresses the interference is generated from the estimate by second-order statistics.

Abstract: Provided is a radar apparatus for use on a vehicle and for detecting one target or two or more targets present in a scan range by scanning the scan range with a radar beam, which has a means for obtaining prior target data by scanning the scan range with the radar beam, a grouping means for carrying out grouping of the prior target data according to a predetermined condition to obtain group data, and a target recognition means for identifying the group data and prior target data remaining without being grouped, as detection data corresponding to respective targets and carrying out recognition of each target corresponding to each detection data. The grouping means makes provision of a plurality of predetermined conditions, selects one condition or two or more conditions according to position information of prior target data to be grouped, and carries out the grouping based on the condition(s) selected. This radar apparatus for use on the vehicle can accurately perform the grouping of point data.

Abstract: The invention relates to a method for measurement of the radar target cross section of an object with both moving and fixed parts, which method comprises a first measurement with high frequency resolution, from which information can be extracted on modulations in the signal received that derive from moving parts of the object and fixed parts of the object respectively. The invention is characterized in that the method comprises a second measurement with high range resolution, and filtering of the measuring result obtained from the second measurement, which filtering is performed around a certain frequency that is obtained by means of the measuring result from the first measurement.

Abstract: A radar apparatus comprising: a receiving antenna having an array antenna in which a plurality of antenna elements are arrayed in a horizontal direction; and a signal processing section for carrying out recognition of a target existing in a predetermined horizontal bearing range from receive signals received by the receiving antenna, by electrically carrying out horizontal scanning of an antenna pattern of the receiving antenna, wherein at least one of the antenna elements is placed with a shift in a vertical direction, and wherein the signal processing section detects an altitudinal bearing of the target by a monopulse method by use of a receive signal from the antenna element with the shift in the vertical direction.

Abstract: A radar apparatus is provided with signal converting means for FFT-transforming an output signal of reception means for detecting a reception electromagnetic wave; amplitude peak value detecting means for detecting a peak value of an amplitude level from a spectrum made by data converted by this signal converting means; beam scanning means for changing a beam direction of a transmission electromagnetic wave and also a beam direction of the reception electromagnetic wave; and measured-angle processing means operated in such a manner that when the same target object can be detected along a plurality of beam directions which are changed by the beam scanning means, an angle of the target object is calculated by employing the peak value of the amplitude levels along the respective directions, acquired by the amplitude detecting means, whereas when the target object is detectable only along a single beam direction, the angle of the target object is judged as preset angles D1, E1, F1.

Abstract: A method of determining a relative permittivity (&egr;r) of concrete including providing a radar apparatus to be positioned on a concrete mass and having a transmitting antenna (2) for emitting a radar wave into the concrete mass and a receiving antenna (3) for detecting a cross-signal generated by the radar wave emitted into the concrete mass by the transmitting antenna, electronically processing the cross-signal, and determining the relative permittivity (&egr;r) by determining, with an algorithm, a frequency-dependent amplitude shifting in a spectrum of a signal section with in a predetermined time slot (t1); and using the so determined permittivitiy for depth scaling and determining presence of foreign bodies.

Abstract: A method and system for analyzing a wooden structure, such as a utility or telecommunications pole, are provided. A location for the wooden structure is identified. A first radar signal is propagated towards the wooden structure with a radar antenna while the radar antenna is motion along a navigation path in the vicinity of the wooden structure. A reflected radar signal is received from the wooden structure, from which a determination is made whether the wooden structure contains a structural anomaly.

Abstract: Methods and apparatus for detecting objects are disclosed. In one embodiment of the invention, a person entering a secured or “Safe Zone™” is illuminated with low-power polarized radio waves. Differently polarized waves which are reflected back from the person are collected and measured. In a preferred embodiment of the invention, concealed weapons are detected by calculating the difference of a pair of differences between levels of different polarized reflected energy in the time domain, and by using signal processing methods and apparatus to improve the reliability of the detection process. Alternative embodiments of the invention may be used to detect a wide variety of objects other than concealed firearms. The invention may be used for inventory control or to thwart shoplifting.

Abstract: The invention particularly relates to the detection of fast-flying targets by means of an HPRF radar system that operates with a plurality of switchable pulse-repetition frequencies (PRFs). In the method, a high velocity resolution is attained, which permits a reliable detection of a multiple-target situation. At the same time, a precise range determination is attained with a high range resolution by means of a pure transit-time measurement of the pulses. The length of the used range gates is selected to correspond to the anticipated target length.

Abstract: A radar processing system is disclosed with an improved cluster target resolution capability. The invention provides a system and method for processing radar returns and generating first and second contiguous range/doppler cells. Within the cells, first and second dichotomous angle measurements corresponding to radar returns in the first and second contiguous range/doppler cells are derived. An adaptive threshold is then applied to the angle measurements to determine whether the first and second measurements correspond to first and second targets in the first and second range/doppler cells respectively.

Abstract: A radar apparatus is comprised of; transmitting means for outputting a transmission electromagnetic wave; receiving means for IQ-phase-detecting a reception electromagnetic wave received when a transmission electromagnetic wave is reflected from a target object and returned from the target object; signal converting means for FFT-processing an output signal of the receiving means; and signal processing means in which if there are one pair of spectrums having positive and negative peak values of amplitude levels, while absolute values of frequencies thereof are identical to each other, among the data converted by this signal converting means, then it is so judged that such a spectrum having a large peak value of an amplitude level is a true spectrum, and both a distance and a relative speed between the target object and the radar apparatus are calculated by employing the frequency of the judged true spectrum.

Abstract: In a radar system having a transmitter that produces pulses to be radiated by an antenna and a receiver that detects target information, complex demodulation is performed on an attenuated and limited waveform of the transmitter produced pulse. A matched filter is generated responsive to the complex demodulated waveform that is a time reversed conjugate image of the waveform corresponding to the produced pulse. Complex demodulation is performed on the return signal received by the receiver corresponding the produced pulse and the complex demodulated return signal is correlated with the matched filter that corresponds to the time reversed conjugate image of the waveform of the produced pulse.

Abstract: A radar apparatus is comprised of: receiving means for IQ-phase-detecting a reception electromagnetic wave received when a transmission electromagnetic wave is reflected from a target object and returned from the target object; signal converting means for FFT-processing an output signal of the receiving means; and amplitude level correcting means in which if there are one pair of spectrums having positive and negative peak values of amplitude levels, while absolute values of frequencies thereof are identical to each other, among the data converted by this signal converting means, then the amplitude level having the larger peak value is corrected so as to acquire a peak value of a true amplitude level.

Abstract: The invention relates to a method for monitoring the earth's surface with a moving aircraft using a radar sensor with a synthetic aperture. In order to produce high resolution radar images, the flight parameters of the aircraft are also required. According to the inventive method, key parameters, such as speed and acceleration, are detected in the sight line of the radar sensor from the radio signals received. One of the advantages of the invention is that an inertial navigation system (INS) is no longer required for this purpose.

Abstract: In order to produce relative velocity signals in accordance with the relative velocity between a following and a preceding vehicle, a Doppler signal transmitter, which targets the preceding vehicle, is attached to the following vehicle. The thus obtained Doppler signals impinge on a signal processor which analyzes the frequency spectrum of the Doppler signal. Velocity signals are formed from the frequencies within this frequency spectrum, which frequencies lie outside the range of those frequencies caused by the velocity of the following vehicle moving relative to the surface.

Abstract: A series of police doppler single mode radars and a multimode police doppler radar, all with direction sensing capability are disclosed. A quadrature front end which mixes received RF with a local oscillator to generate two channels of doppler signals, one channel being shifted by an integer multiple of 90 degrees in phase relative to the other by shifting either the RF or the local oscillator signal being fed to one mixer but not the other. The two doppler signals are digitized and the samples are processed by a digital signal processor programmed to find one or more selected target speeds. Single modes disclosed are: stationary strongest target; stationary, fastest target; stationary, strongest and fastest targets; moving, strongest, opposite lane; moving, strongest, same lane; moving, fastest, opposite lane; moving, fastest and strongest, opposite lane; moving, fastest, same lane; moving fastest and strongest, same lane.

Abstract: Apparatus and methods for processing RF signals are disclosed. A method according to the invention includes receiving a set of time domain energy samples representing signal energy present in an RF spectrum, transforming the set of time domain energy samples into a set of frequency domain power samples, determining from the set of frequency domain power samples whether a signal of interest is present in the RF spectrum, and forwarding to a follow on system a subset of the set of frequency domain power samples, wherein the subset corresponds to the signal of interest. Transforming the time domain samples can include dividing the set of time domain energy samples into a plurality of N windows, each of which is associated with a predefined window period, and performing an FFT on each said window to generate a set of K frequency bins, wherein each frequency bin has a value based on energy present in a predefined frequency band during the corresponding window period.

Abstract: In a procedure for the elimination of interferences of short duration, such as pulses, in a radar unit of the FMCW type, the transmitted and received signals are combined to form a useable signal. According to the procedure, the contribution to the Fourier Transform of the interferences of short duration are filtered out of the Fourier Transform in the frequency domain by an FIR filter with complex coefficients. The procedure requires no additional signal processing between sampling and applying the Fourier Transform, gives very little widening of strong contrasts in the Fourier Transform and is fast and simple to implement in a signal processor.

Abstract: A spinning strip aperture imaging radiometer sensor system and data processing methods for detecting moving objects derived from a plurality of image frames acquired by a strip aperture imaging sensor. A moving object in any individual image frame results in a motion smear signature in the total synthesized image. The motion smear signature is processed to detect the moving objects. One embodiment of the system comprises a rotating strip aperture telescope, a two dimensional detector array that detects images in the telescope's focal plane, a rotation compensation device that prevents rotational smear during integration time of detectors of the array, a signal processor that records a plurality of image frames of a scene imaged by the telescope as it rotates around its optical axis, and that implements method(s) for detecting the moving objects present in the recorded images.

Abstract: A radar ice sounder which employs parallel Doppler processing obtains more reliable and accurate radar ice sounding. The invention uses both incoherent and coherent techniques, in the same paradigm, to achieve simultaneously high Signal-to-Noise Ratio, high Signal-to-Speckle standard deviation Ratio, and high Signal-to-Clutter Ratio.

Abstract: A reference-based autofocusing procedure is particularly suited to existing and future interferometric SAR systems, though the principles are generally applicable to signal processing systems for which there are two partially correlated data sets having relative spectral errors. In an airborne or spaceborne system, the technique only requires some additional steps in the ground processor functions. The invention takes advantage of the fact that in a bistatic system, one antenna phase center both transmits and receives with the usual common-mode cancellation, and can thus be expected to form a reasonably well-focused image. In the second system, with the degraded phase error response, the image provided by the first system is used as a coherent reference to aid the estimation and removal of the relative phase errors between the two.

Abstract: A radar device capable of discriminating a person possessing metals from a person having no metals by transmitting a radio wave includes a voltage controlled oscillator for generating a radio wave, an antenna for transmitting the radio wave generated by the voltage controlled oscillator and for receiving a reflected wave from metals as an object irradiated by the radio wave transmitted by the antenna, a multiplier for detecting a beat component of the wave transmitted by the antenna and the reflected wave received by the antenna, and an FFT operator for analyzing a frequency spectrum of the beat component detected by the multiplier, a recording unit for previously storing a predetermined reference pattern, and a comparison unit for comparing the analyzed result by the FFT operator with the reference pattern stored in the recording unit.

Abstract: A signal process is provided for radar interference mitigation in SAR data and to perform several functions. Initially, the algorithm separately removes the average range bias of the I-channel and the Q-channel data. Next, I- and Q-channels are equalized by properly compensating their phase difference and gain imbalance due to either constant or random timing jitters. The current implementation well compensates relative I/Q timing jitters within two sampling time intervals which, for the FOPEN III receiver, are 4 nanoseconds. Graceful performance degradation of the algorithm is expected when timing jitter exceeds two sampling intervals. For example, phase jitter on the order of 5 sampling intervals will be partially but not perfectly corrected. Following the I/Q equalization, adaptive RFI rejection is performed. The FOPEN III data bandwidth may also be reduced 50% with hardly any information loss.

Abstract: The present invention provides a small-size image radar apparatus to be mounted on an aircraft, having a high resolution not only the flying direction but also in the direction vertical to the flying direction. The image radar apparatus comprises a transmission antenna 2, a plurality of independent reception antennas 5.sub.1, 5.sub.2, and a computer 10 for simultaneously executing a two-dimensional phase synthesis. The synthesis result is obtained as a two-dimensional image.

Abstract: A method of determining the ability of a medium to absorb electromagnetic waves including placing antenna unit (10) having spaced transmitting and receiving antennas (2 and 3) on a limiting surface of a medium (13), emitting, with the transmitting antenna (2), a radar wave into the medium (13) which is detected as a cross-signal by the receiving antenna (3), pre-processing and digitalizing the cross-signal, and, thereafter, analyzing the cross-signal with an algorithm for determining the ability of the medium to absorb electromagnetic waves and, thereby, a type of the medium; and an electromagnetic sensor the operation of which is based on the method.

Abstract: A radio wave receiving apparatus including having improved antenna resolution. The apparatus includes a signal processing circuit; a circuit for performing the Fourier transform with respect to an azimuth of an electric field signal outputted from an antenna receiving circuit; a circuit for performing the Fourier transform with respect to an azimuth of the antenna pattern of an antenna; a circuit for dividing the Fourier transform signal resulting from the electric field signal by the antenna pattern Fourier transform signal; and a circuit for passing the divided signal through a low-pass filter in respect of azimuthal frequency and then subjecting it to a Fourier inverse transform in respect of azimuth, so as to output the signal after the Fourier inverse transform as a final antenna output, thereby improving the antenna resolution by using a transfer function in the azimuthal frequency domain resulting from the Fourier transform of the antenna pattern with respect to an azimuth.

Abstract: In a continuous wave Doppler system in which a fixed transmitter transmits a continuous wave signal to be reflected by moving targets and by fixed structure, an aircraft receives the reflective signals at two spaced apart antennas. The signals reflected from moving targets are distinguished from ground clutter reflected from fixed structure by the phase difference between the Doppler signals receive by the two antennas. The signals reflected from moving targets are distinguished from the ground clutter in response to the phase difference between the Doppler signals received by the two antennas being not equal to a phase difference value determined to be the phase difference for clutter signals. The phase difference value for clutter signals is determined from a function expressing the phase difference value as a linear variation with the Doppler frequency of the signals.

Abstract: A method and apparatus for detecting the presence of objects in a vehicle operator's blind spots. The apparatus comprises a side-facing Doppler radar system using continuous wave (CW) transmission with frequency modulation (FM) operation from a frequency modulation switching technique. The radar system determines the presence, range and closing rate of detected targets. The radar system detects targets even when operated in adverse weather conditions and will not generate false warnings due to rain clutter caused by wet roads and other wet surroundings. The radar system uses ranging techniques to reject false targets that are detected outside of a predetermined target detection zone. In accordance with the present invention, the radar system indicates that a target is detected if and only if any part of the target is within the detection zone and it: (1) remains in front of the antenna for at least TH1 seconds; (2) is at a range between Range.sub.min and Range.sub.

Abstract: A procedure for the elimination of interferences of short duration, such as pulses, in a radar unit of the FMCW type where the transmitted and received signals are combined to form a useable signal is provided. According to the procedure, interferences in the useable signal are detected and eliminated in the time domain and the part of the useable signal with interference is reconstructed by extrapolation based on samples without interference. Thus, the occurrence of interferences is prevented in the complex Fourier Transform of the type that is generated by known methods of clipping the signal.

Abstract: In an FM-CW radar, a receive section has an array antenna in which a plurality of element antennas are arrayed as receive antennas, and a plurality of mixers for generating a beat signal of each channel from a receive signal for each element antenna, and a signal processing section comprises a first device for performing analog-to-digital conversion of the beat signal of each channel into a digital beat signal of each channel and storing it, a second device for performing a Fourier transform process for the digital beat signal of each channel to obtain Fourier transform data of each channel, a third device for performing a phase shift process according to beam direction angles for the Fourier transform data of each channel and thereafter synthesizing the Fourier transform data of each channel every beam direction angle to obtain Fourier transform data of each beam direction angle, and a fourth device for detecting a range to an object and a relative velocity of the object from the Fourier transform data of ea

Abstract: A FMCW radar tank level gauge (14) that measures a level (13) in a tank (10) by obtaining a set of phase shift data points of mixed transmitted waves and received waves. The set of spectral data phase shift values has a received target marker indicating the level. An adaptive set of masking threshold phase shift values corresponding to at least a portion of the spectral data phase shift values are calculated. The adaptive set of masking threshold values are compared with the corresponding spectral data values to identify at least one spectral data value associated with the level. The level of the tank is calculated from at least one spectral data value and the level of the tank is reported.

Abstract: The present invention relates to radars and sonars, and more particularly to a synthetic-band technique of pulse compression making it possible to reach a very high distance resolution. Synthetic band consists in transmitting a waveform pattern consisting of a string of N coherent elementary pulses, linearly frequency-modulated, following one another at a recurrence frequency F.sub.r, of rectangular frequency spectra of elementary band B and of stepped carrier frequencies such that their frequency spectra will link up exactly one ahead of another to form a global spectrum of width N.times.B. On reception, the frequency spectra of the signals received in return for the N elementary pulses of a pattern are extracted by calculation, translated and juxtaposed so as to reconstruct a global frequency spectrum of width N.times.B and then compressed. Pulse compression is thus obtained which is equivalent to that which would result from the transmission of a waveform having a single pulse of frequency band N.times.

Abstract: A Fast Fourier Transformation (FFT) processing is disclosed that measures FFT output phase standard deviation over a number of consecutive FFT runs. The system corrects FFT output phase in an organized fashion for all potential signal filter offset positions while measuring changes in phase standard deviation, and selects the filter offset where the minimum standard deviation occurs. The system utilizes pseudo coherent integration to enhance traditional integration, where the pseudo coherent integration locates the mean phase shift within the number of FFTs integrated, and corrects all FFT runs by this mean shift value. The integration multiplies the magnitude of each FFT filter output by the cosine and sums all FFTs in the integration period for the respective filter.

Abstract: A down range returns simulator for generating simulated radar reflected returns for testing advanced radar waveforms and associated signal processing. The simulator generates return signals based from real mission data, data transforms, arbitrary reference waveform convolutions, and radio and intermediate frequencies. The simulator includes a source of field data, synthetic target, an analog to digital converter for generating digital waveform returns, and RF/IF waveform generator, and a source of clutter waveform characteristics (OPINE, weather, and electronic counter-measures effects). The RF/IF waveform generator uses FFTs and IFFTs in order to develop realistic digital samples for evaluation software and Doppler images. The simulator apparatus provides a target return simulation as if received by radar in a down range mission flight test without the costly expense of conducting a mission flight test for collecting the appropriate data signatures for evaluation.

Abstract: A Deramp type radar used in synthetic aperture radar for radar imaging transmits coherently repeated linear frequency-modulated pulses and carries out a sort of pulse compression in reception by demodulation of the echo signals received by means of a frequency ramp that reproduces all or part of a transmitted pulse, and by a Fourier transform performed in range. The application to a Deramp type radar signal of a standard SAR processing is disturbed by the fact that, in this signal, the effectively demodulated part of an echo signal due to a target has a position with respect to this echo signal and a duration that are variable as a function of the distance from the target to the radar. The proposed method makes it possible to eliminate this disturbance by means of a particular choice of a common temporal support used for the demodulation of the signals of all the targets of the useful swath and a phase correction applied to the level of the pulse response of the image focusing filter of the SAR processing.

Abstract: An FM-CW radar apparatus permits proper pairing between beat frequencies in an up interval and beat frequencies in a down interval and comprises a peak extracting section for extracting level peaks at each scanning angle of beat frequencies, each beat frequency being a frequency difference between a received wave and a transmitted wave, in each of a modulation frequency increasing interval and a modulation frequency decreasing interval; a grouping section for grouping level peaks of approximately equal beat frequencies adjacent in a scanning direction to create level peak groups having respective typical scanning angles, for either of the increasing-interval level peaks and decreasing-interval level peaks thus extracted; a pairing section for pairing a level peak group in the increasing interval with a level peak group in the decreasing interval where the level peak groups have an equal typical scanning angle; and a calculating section for calculating target information from beat frequencies of the increasing

Abstract: A ranging device is disclosed that monitors for changes in a scene of interest. The ranging device includes a transmitter that sends pulses into the scene, a receiver that generates pulse samples in response to pulse returned from the scene, and a target discriminator that analyzes the pulse samples. The target discriminator detects targets entering the scene, targets leaving the scene, and targets moving in the scene through the use of at least one non-averaging statistical characteristic of the pulse samples. The target discriminator may generate short term and long term high order statistical samples in response to the pulse samples as well as detector samples consisting of the ratio of high order statistical samples. The detector samples are highly indicative of the presence or absence of a target in the scene.

Abstract: A layered structure is divided into a plurality of regions. Transmission line equivalents (Green's functions) in the spectral domain are formed between all regions within the layered structure. The spectral domain Greens' function are converted to the spatial domain using a near field and a far field computed for those regions part of a component within the layered structure. The far field is extracted from a compressed database computed from the transmission line equivalents and descriptive of the layered structure. The near field is computed using a prioritization mechanism. Priority is assigned in accordance with the amplitude of a source and the length of the path between regions of interest.Once the physical characteristics of the layers used in the fabrication process of the IC are identified, the database used for computation of the far field is compiled and compressed, and remains unchanged for each new parameter extraction.

Abstract: A modulation signal generating section produces a modulation signal for controlling an oscillation frequency of a voltage-controlled oscillator. The modulation signal generating section comprises a triangular wave oscillator producing a linear modulation component of a triangular waveform which varies the modulation frequency linearly, a sine wave oscillator producing a cyclic modulation component of a sine waveform which varies the modulation frequency cyclically, and a signal adder producing the modulation signal by adding the linear modulation component and the cyclic modulation component. A transmitting signal frequency modulated by the modulation signal is mixed with a received signal and produces a beat signal comprising a fundamental wave component of a beat frequency and harmonic components.

Abstract: A bi-static spread spectrum digital radar including a transmitting antenna and a receiving antenna array separate from and positioned at a distance from the transmitting antenna. The transmitting antenna transmits a pseudo random digital signal as produced by a pseudo random digital signal generator. The receiving antenna array receives signals simultaneously and parallely as reflected from a target by the transmitting antenna. A plurality of analog-to-digital converters are connected respectively to each element of the receiving antenna array so as to convert the received analog signal into a digital signal. Digital beams are produced and directed to a set of digital receivers. A processor is provided so as to produce a digital output from the set of digital receivers.

Abstract: A digital signal processor (DSP) traffic radar utilizing pulses from the patrol vehicle's electronic speedometer to steer the DSP's search of Doppler return information for the patrol vehicle's radar return signal, to improve target identification and minimize inaccuracies. In moving mode, when the patrol vehicle comes to a stop, no pulses are received by the DSP and therefore the patrol speed is set to zero, eliminating false association with other moving targets.

Abstract: A method of radar imaging moving objects, especially ground traffic at airports, uses inverse synthetic aperture radar (ISAR). The two-dimensional location distribution of backscatter centers of the object is detected. A plurality of range bins are provided for suppressing of interference, created because of Doppler shifts, in microwave images represented in the form of pixels. Only those pixels are considered to be active which exceed a defined intensity threshold value, which had previously been determined as a fixed fraction of the maximally present pixel intensity. A range area with interference is determined with the aid of a method wherein the threshold is exceeded and wherein the number of active pixels in the individual successive range bins is counted, and wherein image opening is performed in the detected interfered range area, which consists of a succession of a single or several repeated "erosions" and "dilatations".

Abstract: A processing method for use in providing improved SAR imagery at high duty factors that provides for enhanced radar sensitivity. Radar signals are transmitted that embody a high duty factor ultra-high resolution SAR waveform generated using a biphase code with a predetermined high pulse compression ratio. Received radar returns comprising a SAR map are Fourier transformed and multiplied by a stored set of complex weights. The resultant Fourier transformed complex weighted SAR map is then inverse Fourier transformed to obtain compressed range bins. The inverse Fourier transformed SAR map is then processed for display.