Abstract: Providing multi-spot inverse synthetic aperture radar (ISAR) imagery is disclosed. Embodiments of techniques in accordance with the present disclosure may advantageously improve multiple target discrimination, detection, identification, and tracking using ISAR imaging. In an embodiment, an inverse synthetic aperture radar (ISAR) method for producing multiple ISAR images from a single waveform includes transmitting a chirp signal into a dwell surveyed by the antenna beamwidth. Multiple dechirp reference signals may be generated to demodulate return signals from the dwell at multiple selected intervals within a pulse repetition interval (PRI) to create demodulated signals.

Abstract: An object ranging system operates by transmitting pulses derived from a frequency-swept signal and determining the beat frequency of a combination of the frequency-swept signal and its reflection from an object. A second (or higher) order harmonic is derived from the combination signal. Accordingly, determination of the beat frequency, and hence object range, is significantly enhanced. The frequency sweep is such that frequency changes occur at a substantially higher rate at the beginning of each the pulse repetition interval than at the end. Accordingly, because the frequency changes are concentrated in the period of pulse transmission, even reflections ‘from a close object, where the time delay between the source signal and the reflection is very short, will cause a high beat frequency.

Abstract: One of the objects of the present invention is to reduce the size of a radar device mounted on a vehicle body. To achieve the object, one aspect of the invention provides a radar device, which is mounted on a vehicle body and detects a target present in a moving direction of the vehicle body, with (1) a transmitting antenna for transmitting a mm-Wave that forms an electric field having a width equivalent to the width of the vehicle body at a position away in a moving direction of the vehicle body by a distance corresponding to the most-approached distance defined between the vehicle body and the target and (2) two receiving antennas for receiving the reflected mm-Waves at mutually different positions.

Abstract: A method for a radar for detecting a noise floor level of an electric signal corresponding to an incident radio wave received by the radar, the incident radio wave including a return of a radar wave that is transmitted from the radar toward a measuring range of the radar to detect target object characteristic including presence of a target object within the measuring range of the radar, a distance between the target object and the radar, and a relative speed of the target object to the radar is provided. The method includes steps of: calculating a histogram of intensities of frequency components, the frequency components exceeding a predetermined value relating to the measuring range, and extracting an intensity having the maximum height in the histogram as the noise floor level of the electric signal.

Abstract: An integrated circuit for measuring the distance and/or velocity of objects, having: a high-frequency signal generating device for generating a first HF signal having a predefined frequency and a predefined modulation curve from at least one LF signal; a diplex/mixing device, which is coupled to the high-frequency signal generating device for determining a frequency offset between the first HF signal and a reflected second HF signal; a transceiver device, which is coupled to the diplex/mixing device, for sending the first HF signal and simultaneously receiving the reflected second HF signal, which is a function of a predefined modulation curve of the first HF signal and a distance to a reflecting object; and an adapter device, which is coupled between the diplex/mixing device and the transceiver device, for adapting the impedance of the transceiver device as a function of the frequency of the first HF signal.

Abstract: This invention relates to a target detection device and its detection method, comprising: a transmitting unit for transmitting a detecting pulse to detect target which then reflects the detecting pulse to generate a reflected pulse; a plurality of measuring units, located at different positions respectively which receive said reflected pulse and generates measured values of distance and measured values of velocity according to the reflected pulse received; a plurality of two-stage linear Kalman filters, corresponding to said plural measuring units respectively, each of said plural two-stage linear Kalman filters proceeds an operation according to the measured values produced by corresponding measuring unit so as to generate respectively the estimation values of distance, velocity and acceleration; an arithmetic unit connecting to said plural two-stage linear Kalman filters, which proceeds a triangulation operation according to said estimation values so as to generate distance component values, velocity compon

Abstract: In a radar system installed in a vehicle, a first measuring unit measures a first physical relationship between the vehicle and a first object based on a received first echo signal A second measuring unit measures a second physical relationship between the vehicle and a second object based on a received second echo signal. A failure detector detects whether a failure occurs in each of the first and second measuring units. When it is detected that a failure occurs in one of the first and second measuring units, an alternative control unit causes the other of the first and second measuring units to serve as an alternative to the one of the first and second measuring units to thereby measure a corresponding one of the first and second physical relationships.

Abstract: An array antenna includes a first end portion that has a first plurality of antennas arranged with a spacing d therebetween and a second end portion that has a second plurality of antennas arranged with the spacing d therebetween. In the array antenna, a spacing between respective antennas in both the first and second end portions and are closest to a central portion is set to 2d, which is a value obtained from multiplying 2, which is the number of the antennas constituting each of both end portions, by the spacing d for both end portions. The antennas in the antenna array are continuously selected as a transmitting antenna by switching, and continuously emit transmission signals. The antennas in the antenna array are also successively selected as a receiving antenna by switching. In this way, by switching between transmission and reception of the antennas of the antenna array, nine reception channels CH1 through CH9 that are arranged with a uniform phase difference therebetween are obtained.

Abstract: The radar apparatus of the present invention can obtain distance to a target and speed with higher accuracy even when multiple targets are running within a detecting field of a radar. The radar apparatus can transmit a radio wave by alternately switching a section having a frequency slope and a section having no frequency slope with the radar for simultaneously transmitting a couple of frequencies having a frequency difference. Measurement of distance to the target and relative speed is conducted in the above two sections, results of measurement are compared with each other in the adjacent sections, and the result of measurement is determined correct only when there is no inconsistency in these measurement results.

Abstract: An on-vehicle radar device has a transmission section for transmitting a radio wave to an object, a receive section for receiving the radio wave reflected by the object, and a processing section for dividing an object detection range into three or more of a plurality of areas, setting a threshold of an intensity of the radio wave received for each of the plurality of areas, and judging the existence of an object by comparing the intensity of the radio wave and the threshold. This processing section sets, based on an auto-cruise control mode or pre-crash mode of the vehicle, a threshold of a part of an area in the object detection range to be lower than the threshold of the other areas, or changes the threshold of the detection area according to the object detection status.

Abstract: A method and system for determining a position of a vehicle within a field of view using a traffic sensor are provided. This involves (a) mounting the traffic sensor at a fixed location relative to a road; (b) modulating a microwave signal to produce a periodic time-varying modulated signal; (c) radiating the periodic time-varying modulated microwave signal in a radiation beam at a vehicle on a road to generate a reflected modulated microwave signal, wherein the reflected periodic time-varying modulated microwave signal induces a first received signal at a first receiver antenna and a second received signal at a second receiver antenna, the second receiver being spaced from the first receiver; and, (d) determining the position of the vehicle on the road within the field of view based on the periodic time-varying modulated signal, the first received signal, and the second received signal, wherein the position of the vehicle is determinable during a single period of the periodic time-varying modulated signal.

Abstract: An FMCW radar method is presented in which a radar system of a motor vehicle emits and receives radar waves, and in which a distance between an object and the motor vehicle is determined from a frequency shift between transmitted and received radar waves, and in which a speed of an object is determined from phase positions of received radar waves. The method is defined by the fact that in first time periods (T_A, T_B) it is carried out for objects in at least a first partial area (A, B) of the surroundings of the motor vehicle, and in second time period (T_C, T_D, T_E, T_F, T_G) distances, but not speeds, are determined for objects in at least a second partial area (C, D, E, F, G) of the surroundings.

Abstract: A transmission unit emits an electromagnetic wave having the same frequency f as an output signal from a sending unit in a direction of a measurement axis. A detecting unit performs synchronous detection on a reflected wave detected by a directional coupler by an in-phase signal and a quadrature signal of the transmission signal, and by extracting DC component from the detection signal, detects the in-phase component and quadrature component of the reflected wave. An analysis signal generating unit mixes the in-phase component and quadrature component of the reflected wave and signals having periodicity corresponding to a prescribed distance, and using only one of the resulting side bands, generates an analysis signal. Fourier transform unit finds distance to the object of measurement from a profile obtained by Fourier transform of the analysis signal.

Abstract: The present invention relates to a target tracking method of radar with frequency modulated continuous wave, which transmits a transmitted signal to receive a return wave of the transmitted signal that is used for detecting the target and obtaining the relative distance between the target and the radar. The target tracking method includes transmitting a frequency modulated continuous wave and receiving the reflected wave; getting a reflected wave corresponding to the target by detecting the reflected wave; getting a range gate error by seeking the plurality of the range gates corresponding to the reflected wave; and getting a position and a speed of the target at next time by knowing the position of the target at present time basis of the range gate error. Hence, the relative distance between the radar and the target is got.

Abstract: A level measuring instrument has a variable transmitting power for measuring a filling level in a tank. The level measuring instrument includes a generator unit selectively generating different transmitting powers. The generator unit is controlled so that the transmitting power is respectively adapted to the corresponding environmental conditions. For this purpose, the generator unit has for instance two different oscillators, which are driven selectively.

Abstract: A radar for detecting a target wherein a standard deviation of the amplitude of a beat signal from a transmission signal and a reception signal is determined for a predetermined period. A threshold is determined by adding a predetermined value to the standard deviation or by multiplying the standard deviation by a predetermined coefficient. The presence or absence of interference on the beat signal is detected according to the presence or the absence of an amplitude greater than the threshold. For example, an amplitude exceeding the standard deviation×2 is considered a spike noise (SPN), i.e., as “presence of interference”. The threshold used for detecting peaks appearing on a frequency spectrum is then increased. This allows detection of the presence or the absence of a spike noise superposed on the beat signal to be performed more certainly, thereby enabling processing according to the presence or the absence of interference.

Abstract: A radar includes a transmission section, a heterodyne reception section, a power supply section and a detection section. The transmission section emits a transmission wave to a target. The heterodyne reception section receives a reflected wave from the target. The power supply section supplies power to the reception section. A switching frequency of the power supply section is in synchronization with a local oscillation frequency of the reception section. The detection section determines that the switching frequency is out of synchronization with the local oscillation frequency when a certain peak frequency existing in an output signal of the reception section before a transmission state of the transmission section is changed still exists in the output signal of the reception section after the transmission state of the transmission section is changed.

Abstract: The present invention provides a radio signal radiation system that alleviates the necessity of a highly specified pass band reception filter and a high performance/reliability amplifier. The radio signal radiation system includes an optical modulator; a light source for inputting an optical carrier wave into the optical modulator; a power source for applying a modulating signal having a frequency Fm on the optical modulator to superimpose a sideband wave onto the carrier wave, the modulating signal having an amplitude of N-times the drive voltage of the optical modulator; a light receiver to receive and convert the outgoing light into an electrical signal; and a radiating means for radiating a radio signal based on the electrical signal, wherein the sideband wave is superimposed at a position shifted by n×fm.

Abstract: The present invention is a combined aircraft TCAS/Transponder with common antenna system and transmitter. Common TCAS/Transponder multi-monopole top and bottom antennas may be connected to a top and bottom antenna modules, the top and bottom antenna modules being electrically coupled to the combined TCAS/Transponder transmitter/receiver block through connection lines.

Abstract: A frequency modulation radar apparatus for vehicle use can suppress the influence of noise to avoid incorrect estimation due to noise thereby to provide a beat frequency with high accuracy and at high speed without increasing the frequency resolution of the beat frequency that causes an increase in an observation time. The apparatus includes a frequency correction section that calculates a corrected frequency (fn+?) by adding an amount of frequency correction (?) to the frequency (fn) of a peak signal, and a CPU that calculates a distance or a relative speed to a target object based on the corrected frequency (fn+?). In an FFT calculation section, the frequency (ft) of the true peak signal is calculated based on the characteristic of a window function, and if the frequency (ft) thus calculated is determined as an incorrect estimation, the frequency of the true peak signal is further corrected.

Abstract: While an FM-CW mode for sensing an object, in which a frequency of an electromagnetic wave transmitted from a transmission/reception antenna 6 is continuously modulated, and also, a CW mode for judging an abnormal condition, in which the frequency of the electromagnetic wave to be transmitted from the transmission/reception antenna 6 is not modulated are switched, an abnormal condition judging section judges an abnormal condition when a signal level of a reception signal of the FM-CW mode is smaller than, or equal to a first judging threshold value, and also, a signal level of a reception signal in the CW mode is smaller than, or equal to a second judging threshold value which is higher than the first judging threshold value.

Abstract: A radar including a target measurement component, a differential velocity calculator and an overall velocity determination portion. The target measurement component transmits and receives an electromagnetic wave over a detection range repeatedly at measurement intervals to measure a position of a target in the detection range and measure a Doppler velocity of the target based on a Doppler shift of the electromagnetic wave reflected from the target. The differential velocity calculator determines a differential velocity of the target based on a change in position of the target during consecutive measurement intervals. The overall velocity determination portion determines a current overall velocity by calculating a weighted average of the Doppler velocity, the differential velocity, and a previously determined overall velocity.

Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.

Abstract: In a radar system, harmonic excitation of an antenna is carried out in different frequency ranges. The antenna characteristic which varies as a function thereof is used to analyze different solid angle ranges around an object.

Abstract: On/off timing of an amplifier and timing of antenna selection are accurately adjusted. When adjusting the on/off timing of the amplifier, modulation of a transmit signal is stopped, and a switch is set so as not to select any one of the antennas, thereby totally reflecting the transmit signal; in this condition, the timing is controlled so that the average value of the output level of a mixer becomes a minimum. When adjusting the antenna selection timing, modulation of the transmit signal is stopped, and a reflective object is placed in close proximity to the antenna; in this condition, the timing is adjusted so that the average value of the output level of the mixer becomes a maximum.

Abstract: A FM-CW radar system comprises a frequency modulated continuous wave digital generator that produces both in-phase (I) and quadrature-phase (Q) outputs to orthogonally oriented transmitter antennas. A linearly polarized beam is output from a switched antenna array that allows a variety of I-and-Q pairs of bowtie antennas to be alternately connected to the transmitter and receiver. The receiver inputs I-and-Q signals from another bowtie antenna in the array and mixes these with samples from the transmitter. Such synchronous detection produces I-and-Q beat frequency products that are sampled by dual analog-to-digital converters (ADC's). The digital samples receive four kinds of compensation, including frequency-and-phase, wiring delay, and fast Fourier transform (FFT). The compensated samples are then digitally converted by an FFT-unit into time-domain signals. Such can then be processed conventionally for range information to the target that has returned the FM-CW echo signal.

Abstract: The present disclosure relates to a radar device and technique for detecting the presence of objects located in the near-field of a frequency modulated, continuous wave (FMCW) radar device. The technique includes transmitting and receiving a frequency modulated signal, generating an intermediate frequency signal based on the transmitted and received signals, and analyzing the frequency content of the intermediate frequency signal. The frequency content of the intermediate signal is analyzed without filtering out a carrier signal.

Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.

Abstract: The invention relates to a sensor comprising a housing, inside of which a transmitting antenna array that transmits electromagnetic transmission signals in a radiation area and a receiving antenna array that receives received signals reflected by at least one object located within the radiation area are provided. The inventive sensor is designed in such a manner that the transmitting antenna array is provided for transmitting transmission signals in a main radiation area (3) and in a secondary radiation area (4) situated at an angle, thereto, and in that the receiving antenna array (TX) is provided for receiving received signals reflected in both radiation areas (3, 4). This makes it possible, for example when used in a monitor vehicle (5), to monitor the area behind and next to the motor vehicle (5) with a single transmitting antenna (1).

Abstract: There are provided a radar device that transmits a frequency modulation-continuous wave (FM-CW) and outputs an up-beat frequency and a down-beat frequency, a pairing processing section that conducts pairing of the up-beat frequency and the down-beat frequency at specified sampling intervals, a target-object detecting section that detects target objects around the vehicle, obtaining a distance from the vehicle to the target object and a relative speed between the vehicle and the target object based on the up-beat frequency and down-beat frequency that are paired, and a prediction processing section that obtains a prediction data for each target object for a next sampling timing. The pairing processing section conducts the pairing with priority to a specified target object that has a high certainty of the prediction data. Thereby, the pairing of the up-beat and down-beat frequencies can be conducted precisely and quickly.

Abstract: An FMCW radar device executes a frequency analysis for a beat signal in a frequency increase interval and a frequency decrease interval, to obtain frequency components in a predetermined high frequency range exceeding a frequency range corresponding to a target detection frequency range within which a target object for detection should be detected. Then the FMCW radar device calculates a value related to a sum of intensities of frequency components within the high frequency range respectively for each of the frequency increase interval and the frequency decrease interval. In the case that one of the calculated integrals is larger than a threshold, the FMCW radar device determines that the FMCW radar device is interfered with by a nearby radar device.

Abstract: A radar system in which a beat signal is generated by transmitting a transmission signal that is subjected to frequency modulation into a triangular wave and receiving a reflection signal from a target, the beat signal is sampled, and a window function is applied to yield a discrete frequency spectrum. When the window function is applied, a first window function having an amplitude that is gently attenuated from the center of the sampling period toward both sides thereof is applied in a lower frequency band in the frequency spectrum (at close range), and a second window function having an amplitude that is sharply attenuated from the center of the sampling period toward both sides thereof is applied in a higher frequency band in the frequency spectrum (at far range).

Abstract: A method (for example, machine-implemented, e.g., via a receiver), for determining whether a transmitted pulsed-signal is a linear or non-linear frequency modulated (FM) signal, includes: iteratively determining upper and lower bound slopes associated with frequency components of a pulse of a signal during a time period of the pulse; and comparing each determined upper bound slope to a previous or initial upper bound reference slope and comparing each determined lower bound slope to a previous or initial lower bound reference slope in order to determine the linearity, or non-linearity, of the signal.

Abstract: Automotive vehicle including a radar transceiver each including a heterodyne active IMPATT multiplier module arranged to receive a signal from a VCO, a first balance mixer arranged to receive a signal from a VCO, a second balance mixer arranged to receive a signal from a receive antenna and the IMPATT multiplier module and derive a first intermediate frequency signal, a first amplifier for amplifying the output of the second balance mixer and providing the amplifier output to the first balance mixer, and a second amplifier for amplifying the output of the first balance mixer. The vehicle also includes a processor which receives output from the second amplifier of each transceiver and generates a control signal for controlling one or more vehicular components based on the output from the second amplifier(s). The components can be part of a collision avoidance system, blind spot monitoring system and the like.

Abstract: Sensing characteristics of an object includes transmitting a stepped-frequency radar through an object and detecting, with multiple receiving structures, deflected portions of the radar signal. The detected portions are processed to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected. The processed data is analyzed to determine information corresponding to dielectric properties particular positions within the object.

Abstract: A radar is provided with transmitting means for transmitting a signal and with receiving means for receiving a reflection of the transmitted signal. The inventive radar is characterized in that the transmitting means is provided with a transmitting oscillator and the receiving means is provided with an evaluation oscillator. The transmitting oscillator is excited by the evaluation oscillator and/or the evaluation oscillator is excited by the transmitting oscillator in a quasi-phase coherent manner.

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: Systems and methods for detecting targets using pulse-compressed radar signals are disclosed. In one application, relatively small targets that are masked by the time-sidelobes of a larger target's return signal can be detected. The methods include a signal expansion type algorithm that is used to process the pulse-compressed return signal. Specifically, a generalized Fourier expansion expression having a summation of PSF terms is used to expand the pulse-compressed signal. Each term represents a respective target and includes a point spread function and a complex coefficient. The signal expansion procedure can be used to determine a set of optimum complex coefficients, with one coefficient for each range bin. Doppler frequency can be used together with range to optimize the complex coefficients. Next, targets are detected by analyzing each range bin to determine whether the corresponding complex coefficient has an absolute magnitude greater than a pre-determined threshold.

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: 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 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: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.

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: 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 radar-based distance measurement apparatus comprises a microwave circuit comprising a frequency generator which produces a microwave frequency signal, the frequency of which is modulated by an amount determined by a modulation signal applied to the frequency generator, a temperature sensor which measures the temperature of at least a part of the microwave circuit, compensating means for processing the output of the temperature sensor to produce a compensated temperature signal using information derived from the drive signal and an echo signal detected by a microwave detector; and a frequency regulating means which is adapted to receive the compensated temperature signal and to regulate the frequency of the signal generated by the frequency generator, thereby at least partially correcting for the effect of changes in temperature of the frequency generator.

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: A vehicle positioning and tracking radar system includes a rotating antenna with a pair of spatially separated transmit feeds for simultaneously transmitting a pair of frequency-modulated continuous-wave (FMCW) electromagnetic signals having a first polarisation and a pair of spatially separated receive feeds for receiving an electromagnetic signal having a second polarisation, wherein the first and second polarisations are different from one another, such that the transmit feed and receive feed at the rotating antenna are isolated from each other; and a coded modulated transponder receives transmit signals from the rotating antenna with the first polarization and transmits a receive signal to the rotating antenna with the second polarization.

Abstract: The invention relates to a method for detecting the passage by a vehicle of a determined point for monitoring on a road, wherein from a remotely situated location a radar beam is transmitted continuously to the point for monitoring, reflections from the transmitted radar beam are received at the remotely situated location, and it is determined from the received reflections that the vehicle is passing the point for monitoring. The radar beam can herein be transmitted at an acute angle to the travel direction of the passing vehicle. The detection can be used to activate a red-light camera, to measure the speed of the vehicle or measure the traffic intensity, without sensors, for instance induction loops, having to be arranged in the road for this purpose.

Abstract: Occurrence of interference is detected using sampled amplitude data obtained by oversampling a beat signal. It is detected by comparing the absolute value (|VD|) of variation in the sampled data with a threshold value (TH). When interference occurs, a wideband signal is superposed on the beat signal, and this disturbs the signal waveform of the beat signal to drastically varies its amplitude. Therefore, occurrence of interference can be detected without fail regardless of the scheme on which a radar as the source of an interference wave is based and even when the amplitude of the interference wave is low. In addition, when low-frequency noise is superposed on the beat signal, erroneous detection of occurrence of interference can be prevented.

Abstract: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.