Abstract: A radar device set on an automobile includes a transmitter for transmitting forward a beam of electromagnetic waves, a receiver for receiving reflected waves of the transmitted beam from a vehicle traveling in front, a measuring device for measuring a distance to the vehicle in front based on outputs from the receiver and a command outputting device for outputting a specified command signal when the distance measured by the measuring device is decreasing and reaches a threshold distance below which the measuring device becomes incapable of measuring the distance from the outputs from the receiver, and a beam adjusting device for changing either the elevation angle of the beam or its angular range of vision in response to the command signal.

Abstract: A scan type radar device capable of detecting a lateral position of a target even if a peak showing the lateral position of the target irregularly fluctuates in the lateral direction as well as reducing the mis-pairing. The former is achievable by changing a reference value of the lateral fluctuation of the target when all the past and present target data fluctuate to an extent exceeding the reference value. The latter is achievable by forecasting a representative peak position at this time in both of up-beat and down-beat from the peak position data at the preceding time and carrying out the past-correspondence grouping of the up-beat and the down-beat at this time in the vicinity of the position of the representative peak forecast this time; the pairing being carried out by using the representative peak calculated by the past-correspondence grouping.

Abstract: A vehicle speed sensing system includes an RF transceiver coupled to an antenna for transmitting an RF signal towards the terrain over which the vehicle moves and for receiving a reflected Doppler signal therefrom. The transceiver generates a time-domain in-phase reference signal I and a time-domain quadrature signal Q which is offset in phase by 90 degrees from the reference signal I. A digital signal processor which receives the I and Q signals, and uses a complex fast Fourier transform routine to convert the time domain I and Q signals to frequency domain values I(f) and Q(f). The digital signal processor further processes the I(f) and Q(f) values and generates a speed a direction signal which is unaffected by vehicle vibrations.

Abstract: A method capable of determining whether a target detected by a radar is a stationary on-road object or not is disclosed, wherein a fluctuation in the reception level of a reflected wave from a target is obtained in relation to the distance of the target, a difference in reception level between a maximum point and a minimum point is obtained from the fluctuation of the reception level, and when the obtained difference is larger than a predetermined threshold value, it is determined that the target is a stationary on-road object. Further, slope over the distance between the maximum point and the minimum point is obtained, and when the obtained slope is greater than a predetermined threshold value, it is determined that the target is a stationary on-road object. Further, the distance between maximum points or between minimum points is obtained, and when the obtained distance is smaller than a predetermined threshold value, it is determined that the target is a stationary on-road object.

Abstract: A bistatic radar system (100), method and computer program (178) are provided for mapping of oceanic surface conditions. Generally, the system (100) includes at least one transmitter (102) and at least one receiver (106) located separate from one another, and each having a local oscillator locked to a Global Positioning System (GPS) signal received by a GPS synchronization circuit (134) to provide the necessary coherency between the transmitted and received signals. Preferably, the present invention enables an existing backscatter radar systems to be quickly and inexpensively upgraded to a bistatic radar system (100) through the addition of a transmitter (102) and/or receiver (106) separate from the backscatter radar system, the GPS circuit (134), and use of the computer program (178) and method of the present invention.

Abstract: A police radar and/or laser detector senses radiant electromagnetic signals (e.g. radar, laser) characteristic of a police traffic surveillance device and responds thereto with a displayed and/or audible alert. During periods when no alert is necessary, the detector senses and displays, in numeric or bar graph form, vehicle parameters, such as sound pressure level and acceleration. In addition, calculations based on acceleration provide 0-60 m.p.h. time and quarter mile time. Thereby, the detector enhances information available to the driver without the inconvenience, expense, and clutter of multiple displays.

Abstract: A radar device for measuring the surface velocity of water moving in a horizontal plane in which the radar device is positioned above or below the horizontal plane. The radar device includes a tilt sensor, or accelerometer, to measure the angle of tilt of the radar device with respect to a target point located at a distance from the radar device. The accelerometer generates a signal representing the tilt angle. A processor in the radar device calculates the cosine correction factor that is applied to the measured velocity of the target point. This results in an automatically corrected measured velocity being displayed on the radar device.

Abstract: To measure the absolute speed of a body 100 moving relative to the ground 33 using an onboard speed sensor 1, a radar wave is transmitted towards the ground by an antenna with a wide aperture angle. The wave reflected by a reflecting obstacle on the ground and the transmitted wave are mixed and the frequency content of the low frequency signal obtained is determined. The speed of the moving object and the height of the transmitter and receiver antennas above the ground can then be measured by adjusting a theoretical curve to the time-varying evolution of the Doppler frequency corresponding to the reflecting obstacle.

Abstract: An FMCW radar is provided which may be employed in automotive anti-collision or radar cruise control systems. In a distance measuring mode, only one of channels is used to sample a beat signal continuously, thereby allowing a sampling frequency to be increased up to Nc times that in an azimuth measuring mode and a sweep time in which a transmit signal sweeps in frequency upward and downward cyclically to be minimized. This causes half the sampling frequency to be higher than a frequency component arising sufficiently from a distant target present outside a preset radar range, thereby eliminating an error in detecting the distant target as being located inside the preset radar range.

Abstract: An FM-CW radar system comprises a modulating signal generating means for changing a modulating signal to be applied to a FM-CW wave, a calculating means for calculating a distance or relative velocity with respect to a target object by performing processing for detection by fast-Fourier transforming a beat signal occurring between a transmitted signal and a received signal, and a control means for determining a detection range based on the calculated distance, and for performing control to change the modulating signal, wherein the modulating signal is changed by changing one parameter selected from among a modulation frequency, a triangular wave frequency, and a transmit wave center frequency. The detection range is set to a distance obtained by adding a prescribed distance to the shortest distance detected, or to a distance obtained by subtracting a prescribed distance from the distance of a fixed object.

Abstract: A compact, autonomous motion detecting and alerting system alerts to the movement of objects of interest. Mounted on an environmentally sealed PC board are a transceiver such as a CW radar front-end, connectors, signal processors and a communications device. The system provides early warning of movement of an ice sheet or rubble field via the communication device that may be a cellular telephone. This system is mounted proximate the target surface under observation, oriented at pre-specified offset angles both laterally and in elevation. The target is illuminated and energy reflected therefrom is mixed with a portion of the transmitted signal to produce a difference frequency signal that is processed to establish existence of motion within a pre-specified velocity range. Upon verification of motion, notification is sent to a responsible authority. An autonomous or semi-autonomous power source and integral power management function may be incorporated on the same PC board.

Abstract: The occurrence of an axis displacement in a horizontal direction in a vehicle-to-vehicle distance controlling radar is detected, the amount of the axis displacement is determined, and an azimuth angle is corrected using the thus determined amount of the axis displacement. The frequency with which vehicle-to-vehicle distance control is released or re-set is measured and, if the frequency is higher than a threshold, it is determined that the axis is displaced. The amount of the axis displacement is determined from the angle of the locus of a stationary target. The azimuth angle of the target is corrected using the thus determined axis displacement angle.

Abstract: In a homodyne-receiver radar system used for ranging and/or target detection, the frequency-modulated (FM) transmit phase are removed from the received signal. Removal of the known FM transmit phase from the received signal reduces the bandwidth of the received signal to half that of a system that does not remove the transmit phase. This allows the sampling rate, and thus the processor throughput, to be cut in half. With the FM transmit phase removed, the phase sequence of the processed signal is akin to a delayed version of the transmit signal phase history. This allows the range processing to use segments of a single phase sequence for processing all range gates, resulting in a large reduction in the amount of coefficient storage used for the matched-phase sequences required to process the set of range gates.

Abstract: A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circuit to the VCO. A high-frequency signal subjected to frequency modulation in the VCO is transmitted as a radio wave from a transmission antenna and is reflected on a target and the reflected radio wave is received at a reception antenna. The reception signal and the high-frequency signal are mixed by a mixer to provide a beat signal and frequency shift corresponding to a voltage V1 is detected from the frequency of the beat signal. If the voltage V1 of the modulation signal for detection is switched, the frequency shift corresponding to different voltage V1 can be provided and the frequency modulation characteristic can be detected.

Abstract: A transceiver assembly is provided for use in a Doppler-based traffic radar system for determining the speed of at least one target. The transceiver assembly includes a cover for receiving therein at least some of the component parts of the transceiver assembly. In other words, the cover is positioned over the component parts of the transceiver assembly which are enclosed by a cap removably attached to the cover. A conical antenna horn and turnstile waveguide cavities are formed from a unitary material. The circuitry associated with the transceiver assembly is modularized such that the circuitry may be removed from the transceiver assembly, or more specifically separated from the microwave components of the transceiver assembly, for testing.

Abstract: A process and apparatus to automatically determine whether a police radar is installed in a vehicle which has a coupling between a vehicle speed sensor and the police radar. The process automatically, without any operator input, determines the correct ratio between the true ground speed and the frequency output by vehicle speed sensor at that ground speed. The process and apparatus then use that ratio and the frequency from the vehicle speed sensor to establish a software search window that limits the speed range of the search by the police traffic radar for the true ground speed.

Abstract: In a system for estimating the launch point of a missile, Doppler shifted signals reflected from the missile as it travels from its launch point are used in a Kalman filter to estimate the missile position, velocity and acceleration, in earth centered fixed coordinates. The coordinate system is rotated to a rotated earth fixed (REF) coordinate system in which the X-axis passes through the estimated missile launch point and the Z-axis is made parallel to the missile azimuth as represented by the missile velocity determined by the Kalman filter. The error in the downrange component of the missile launch point is then reduced to a minimum in the REF coordinate system using a square root information filter. The coordinate system is then rotated to a second rotated earth fixed coordinate system in which the X-axis passes through the updated launch point position and the Z-axis is positioned at 45 degrees from the missile azimuth.

Abstract: In an FM-CW radar apparatus, while a distance and velocity of a target are measured by simultaneously transmitting an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction toward this target, physically-required radar signal measuring time thereof can be reduced by ½.

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

Abstract: In an FM-CW radar system, a frequency 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: In a radar, a coupler extracts a part of a transmission signal as a local signal and a mixer mixes a reception signal from a circulator and the local signal so as to output an intermediate frequency signal which is the frequency difference between the transmission signal and the reception signal. An IF-amplifying circuit amplifies the intermediate frequency signal and an AD converter converts the signal to digital data. A DC-removing unit removes a DC component by subtracting the average from the data and an FFT operation unit performs fast Fourier transform so that the distance to a target and the relative velocity of the target are calculated based on a peak included in the frequency spectrum.

Abstract: A system for sensing and measuring the relative motion of an object, comprising a transceiver device configured to transmit a signal toward an object, a plurality of detectors offset in phase to receive the transmitted signal and a reflected signal, and a processor configured with logic to measure a phase shift resulting from the relative motion of the object between the transmitted signal and the reflected signal at the plurality of detectors, wherein the processor is further configured with the logic to relate the phase shift to the relative motion of the object.

Abstract: A method and apparatus for measuring the parameters of atmospheric turbulent flows utilizes the Doppler shifted frequencies of received radar signals backscattered from sound generated aerodynamically by atmospheric turbulent flows. Doppler frequency bandwidths of the received backscattered signals are used to estimate the atmospheric flow turbulence and the mean frequency within a bandwidth is processed to estimate its radial flow velocity. Total flow velocity and the flow velocity angle with respect to the antenna boresight of the atmospheric turbulent flow may be estimated by estimating the radial flow velocity at two radial positions and processing these radial velocities. Processing of the Doppler data is initiated when the total signal power within the Doppler frequency band exceeds a predetermined power level.

Abstract: A continuous signal of a radio frequency source is connected to an antenna using at least one mixer to generate and analyze radar pulses. To generate a radar pulse, the at least one mixer is briefly placed into a state of low throughput loss. After the radar pulse is generated and transmitted, the at least one mixer is switched over to a receive mode to analyze a mixed signal formed by a receive signal, in particular at least one radar pulse reflected by an object, and the continuous signal of the radio frequency source.

Abstract: A Doppler-based radar system and related method are provided for determining the direction and speed of at least one selected target traveling in the same lane as a moving patrol vehicle supporting the radar system independent of the direction of the target relative to the platform. The radar system includes an oscillator to generate a signal, an antenna to transmit the signal toward the at least one target and to receive a return signal reflected from the at least one target, a turnstile in communication with the antenna for receiving the return signal and forming processing signals which are different in phase, and circuitry for determining the direction of the at least one target relative to the platform and the speed of the at least one target dependent upon a mode of operation of the radar system.

Abstract: A police radar and laser detector with networking capability is disclosed. By including the ability to wirelessly transmit the existence or even location of a detected radar or laser source, overall performance can be improved. Transmission of an actual radar or laser location gives other detectors advanced warning. Additionally, transmission of false alarm locations will allow other detectors to reduce false alarms.

Abstract: An intrusion detection system and method are provided that can utilize impulse radio technology to detect when an intruder has entered a protection zone. In addition, the intrusion detection system and method can utilize impulse radio technology to determine a location of the intruder within the protection zone and also track the movement of the intruder within the protection zone. Moreover, the intrusion detection system and method can utilize impulse radio technology to create a specially shaped protection zone before trying to detect when and where the intruder has penetrated and moved within the protection zone.

Abstract: A radar signal processing method and system for detecting target objects of unknown acceleration and having low SNRs which reduces the computational burdens and provides a more efficient way of performing the operation of non-coherent integration. Radar signal processing is conducted according to a predetermined scheme in which partially processed received signal data is selectively stored and reused, reducing redundant processing. The radar system receives return signals frequency shifted from a predetermined frequency scheme by unknown amounts. The received signals are coherently integrated transforming them into frequency domain templates which are non-coherently arranged into an array matrix. The data of the frequency domain templates are processed to form presums which are stored for use in forming higher level presums and for forming acceleration bins. Once the acceleration bins have been formed, they are analyzed to detect the presence of target object return signals.

Abstract: A system for sensing and measuring the relative motion of an object, comprising a transceiver device configured to transmit a signal toward an object, a plurality of detectors offset in phase to receive the transmitted signal and a reflected signal, and a processor configured with logic to measure a phase shift resulting from the relative motion of the object between the transmitted signal and the reflected signal at the plurality of detectors, wherein the processor is further configured with the logic to relate the phase shift to the relative motion of the object.

Abstract: A Doppler-based traffic radar system determines a speed of a moving target from a platform while substantially eliminating the possibility of detection by an operator of the moving target utilizing a traffic radar detector. The radar system includes a controller or digital signal processor for limiting the period of time the system is initially transmitting. The duration of the initial transmission period is limited such that presently available commercial radar detectors are substantially unable to detect and/or elect not to report the presence of the radar signal. Specifically, the radar system is adapted to monitor the number of accumulated digital samples from a reflected portion of the radar signal. Upon receipt of a number of samples sufficient to determine the speed of the target, the radar system ends the initial transmission. Once the samples are obtained, the radar system determines the speed of the target and displays the speed.

Abstract: A Doppler-based radar system and related method are provided for determining the direction and speed of at least one selected target traveling in the same lane as a moving patrol vehicle supporting the radar system independent of the direction of the target relative to the platform. The radar system includes an oscillator to generate a signal, an antenna to transmit the signal toward the at least one target and to receive a return signal reflected from the at least one target, a turnstile in communication with the antenna for receiving the return signal and forming processing signals which are different in phase, and circuitry for determining the direction of the at least one target relative to the platform. In particular, samples of the processing signals are transformed into the frequency domain and cross-correlated forming cross-correlation components.

Abstract: A radar apparatus mounted on a vehicle includes a detecting section and a fault determining section. The detecting section includes a radar unit and detects a detection object using radar wave radiated from a radar unit toward the detection object and reflected radar wave from the detection target to the radar unit. The fault determining section determines whether any fault has occurred in the radar unit, based on the detecting result of the detection object and a movement distance of the vehicle, and generates a fault detection signal, when it is determined that any fault has occurred in the radar unit.

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: A road antenna apparatus includes a road antenna 104 which is mounted on a post 103 and at an elevated position on a road R and establishes radio communication with an on-vehicle radio device 102 mounted in a vehicle 101 which is traveling over the road; and a laser-beam emitting device 111 which is mounted on the road antenna and radiates a laser beam onto a predetermined position 113 on the surface of the road. An offset in the angle at which a road antenna is mounted can be readily ascertained on the basis of a distance between a predetermined position on the surface of the road and a position 114 on the road surface onto which a laser beam is actually radiated.

Abstract: A compact millimeter wave radar transceiver at low cost is provided wherein a direct current voltage applying circuit is coupled to a high frequency line to apply a fast pulse wave without losing a sharp input pulse pattern. A voltage is applied to a negative resistance diode, such as a Gunn diode, which is variably controlled to vary the diode oscillating frequency signal, which signal is outputted as a transmitting wave. The transmitted wave is reflected by a target and received by the negative resistance diode. The received wave is detected as a heterodyne detection utilizing a non-linear property of the negative resistance diode. A frequency difference between the transmitted wave and the received reflected wave is outputted via a low-pass filter and processed to detect the target.

Abstract: A high resolution spectral estimator (HREE) filter coupled to a spectral plotter processes either Doppler frequencies provided from the output of a pulse-Doppler radar or a frequency based output provided by a Fourier transformer coupled to a sensing device to allow the spectral plotter to determine the power frequency spectrum of either the pulse-Doppler radar output or sensing device output. The HREE filter preferably comprises a bank of first order filters tuned to a pre-selected frequency, a covariance estimator coupled to the filter bank for estimating filter covariances, and a decoder coupled to the covariance estimator for producing a plurality of filter parameters. Further, it is preferable that the filters comprising the filter bank be adjustable to permit their being tuned to a desired frequency based on a priori information.

Abstract: The present invention relates to a CW radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles. The present invention further provides that the transmission (s(t)) can be composed of at least four consecutive chirps (A, B, C, D), each having different slopes. The intersection points of all lines in the distance-relative speed diagram from two chirps (A, B) can be calculated from all the ascertained frequency positions K1,n and K2,p. To validate those intersection points, one may observe whether a peak exists in the Fourier spectrum of a third chirp C at a frequency position K3,q, whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram.

Abstract: A Doppler radar transceiver in a traffic monitoring system includes a pyramidal horn antenna having a rectangular aperture and a dielectric lens mounted at the rectangular aperture. Preferably the pyramidal horn antenna is corrugated and the rectangular aperture has a breadth at least twice its width in order to provide a fan-shaped radar beam most effective for detecting moving vehicles in a stream of traffic. To reduce standing waves in the horn antenna that would otherwise cause nulls that would intermittently interfere with detection of a Doppler signal, the dielectric lens has impedance matching means for matching impedance of the dielectric lens to impedance of free space to reduce standing waves in said horn antenna. Suitable impedance matching means include a quarter-wave transformer or a tapered transformer structure at the interfaces between the dielectric body of the lens and the free-space region inside the horn and outside of the horn.

Abstract: The present invention discriminates between moving targets and stationary targets in order to measure distances and speeds of the targets without producing a false target. The invention transmits signals whose modulating frequencies ascend or descend to a target, and receives signals reflected from this target. A frequency spectrum of a beat signal of each target is detected during a modulating frequency ascent period and a modulating frequency descent period. The frequency spectrum of the modulating frequency ascent period and the frequency spectrum of the modulating frequency descent period are used to set a reference spectrum. The reference beat frequencies of either the moving targets or the stationary targets are detected based upon the reference spectrum.

Abstract: A motion detector based on the Doppler principle contains a microwave module for emitting a microwave signal containing at least two frequencies into a room under surveillance and for receiving the radiation reflected from the latter. An evaluation stage is connected to the microwave module and generates first and second Doppler signals from the received radiation. The first and second Doppler signals have a phase difference which is proportional to the distance of an object reflecting the microwave signal. The phase difference is determined by an integral transformation. In addition, the relative size of an object and the direction of travel of an object reflecting the microwave signal can be determined by the evaluation stage.

Abstract: The invention relates to a radar station placed on the surface of the earth, and to a radar system comprising at least two such radar stations. The signal-processing equipment of the radar stations is adapted, at each point of time, to calculate probabilities of target positions and radial target velocity in relation to each individual radar station, based on the signals emitted and received by this station. These calculated values are associated over time, giving cumulative probability measures for target positions and radial velocities in relation to each individual radar station. By providing a system of at least two radar stations, it is possible to calculate the position of a target by associating target positions, such as they are perceived by the different radar stations, with each other by an association of characteristic movements of the target. This is done without having to synchronize the stations.

Abstract: Disclosed is a radar system capable of obviating a problem that a sufficient improvement of an S/N ratio could not be obtained in the prior art, and comprising a transmitter/receiver for detecting a phase of a receiving signal reflected from an observation target, an A/D converter for converting the receiving signal into a digital signal, a range gate for extracting the receiving signal having a time corresponding to the predetermined pulse width, a data dividing unit for dividing the receiving signals in to two groups of data, an FFT unit for fast-Fourier-transforming one group of data of the two groups of data, an FFT unit for fast-Fourier-transforming the other group of data, a complex conjugating unit for taking a complex conjugate of an output of the FFT unit, a complex multiplying unit for performing a complex multiplication for the every same Doppler frequency component with respect to an output of the former FFT unit and an output of the complex conjugating unit, and a complex adder for executing a co

Abstract: A device and process for measuring distances and/or speeds between a motor vehicle and several objects, like mobile targets and fixed targets, has an FMCW radar system, where the motor vehicle transmits a signal, whose transmitting frequency is modulated with at least two frequency ramps. A device detects the receiving signals from the objects and determines the respective straight lines and the intersecting points of these straight lines in a speed-distance diagram. A sorting device sorts out the intersecting points from fixed targets and the related straight lines. A device outputs the distances and/or the speeds, which correspond to the other intersecting points.

Abstract: A system for rapidly acquiring a time reference for the location determination of a wireless communication device. The system includes a wireless communication device (200), a GPS satellite (202) and a communication satellite (208). The method comprises the steps of acquiring a communication satellite signal (210) and using the finite frame time to establish a course time reference. Once the course time reference is established, an absolute device time is determined by the wireless communication device, which as a result is synchronized to the absolute time of the communication satellite (208) to within ten milliseconds. The absolute device time is then used to synchronize the GPS portion of the wireless communication device with the GPS satellite system.

Abstract: An FM-CW radar is provided which may be employed in anti-collision systems or cruise control systems installed in moving objects such as automotive vehicles. The radar analyzes a beat signal in frequency to produce peak frequency components in a modulated frequency-rising range wherein the frequency of a frequency-modulated radar wave transmitted from the radar increases and a modulated frequency-falling range wherein the frequency of the radar wave decreases. If one of peak frequency pairs, each of which is made up of each of the peak frequency components in the modulated frequency-rising range and one of the peak frequency components in the modulated frequency-falling range, lies within a given lower frequency range, the radar identifies the one of the peak frequency pairs as radar data arising from a moving object appearing suddenly in a radar detection zone.

Abstract: A method and apparatus for calibrating range in a radar system. Due mainly to temperature changes in a radar system which cause frequency deviation error, range errors can be introduced into the radar system, thus adversely affecting the determination of the position of targets relative to the host platform. These range errors can be corrected by detecting and accurately estimating the frequency deviation error of a radar system. The present invention improves target position determination performance in a radar system by reducing errors introduced by the frequency deviation error. The present invention relies upon the observation that the Doppler range rate is largely unaffected by frequency deviation error, and thus, is approximately equal to the actual range rate. In accordance with a first range calibration technique of the present invention, the radar system measures the range, Doppler range rate, and azimuth angle of a target during at least two successive time instances.

Abstract: Dual path detection processing in which a low SNR signal processor detects signals over a limited range of low acceleration values and a high SNR signal processor detects signals over a wider range of acceleration values. The low SNR signal processor uses acceleration bins formed from a noncoherent FFT array to detect low SNR signals of far away objects which tend to have lower angular acceleration. Because close proximity target objects tend to have higher SNR return signals, it is not necessary to rely on acceleration bins formed from an FFT array for signal detection. Close proximity targets with high SNR can often be detected in individual coherently integrated FFT templates, despite the likelihood of large acceleration uncertainty from higher angular acceleration rates.

Abstract: Method and device for calculating a velocity of a moving transmitter using Rayleigh-fading of a received radio signal are presented. The method includes the step of making at least two parallel calculations of at least two respective values using the received radio signal. The at least two respective values resulting from the calculations are then used as the basis for making a decision. The decision results in an optimal value for calculating the velocity of the moving transmitter being chosen from among the at least two respective values. Each of the at least two parallel calculations is carried out by respective devices each having at least one filter and at least one level crossing counter.

Abstract: A method and a system for detecting and ranging objects utilize summed and difference signals to determine whether a target is present at a predetermined distance from the system. The summed and difference signals represent corresponding points on two discriminator functions that are derived by summing and subtracting two autocorrelation functions. The two autocorrelation functions are identical functions, except that one has been shifted by a one-bit period. By analyzing the summed and difference signals, the system is able to detect objects that cross a boundary zone located at the predetermined distance from the system. In the preferred embodiment, an optical signal is transmitted by a transmitter of the system to detect a target. Preferably, the optical signal is modulated in accordance with a double concatenated eleventh order Barker-based code. The optical signal is received by an associated photodiode after being reflected by the target.

Abstract: Height-wise positions of objects are detected on the basis of distances to the objects from a vehicle, angles of the objects in a width-wise direction of the vehicle, and angles of the objects in a height-wise direction of the vehicle. A plurality of objects, which satisfy conditions predetermined depending on physical characteristics of delineators, are determined to be objects composing a delineator group. When the detected height-wise position of an object in the delineator group which is nearest to the vehicle corresponds to a predetermined value or less, the delineator group is determined to be a delineator group on a road surface. A determination is made as to whether each object in the on-road-surface delineator group is a non-delineator in response to conditions of the detected height-wise positions of the objects in the on-road-surface delineator group.