Abstract: An object detection system may be capable of sensing a buried object and providing an estimate of the object's depth. The object detection system may comprise a signal generator transmitting one or more signals. At least one of the signals may be directed toward the buried object and reflected off of the object back to the system. At least one of the signals may be transmitted along a variable length path. A correlator may then receive the signals and determine an offset between their arrival times at the correlator. The variable length path may then be adjusted over a range which includes a minimum offset indicating a distance to the object.

Abstract: An audio device may be configured to detect proximity of a user hand based on analysis of audio signals captured by the audio device. For example, the audio device may be configured to perform acoustic echo cancellation based on dynamically calculated filter coefficients. The coefficients may be analyzed to determine proximity of the user hand. The proximity of the hand may be evaluated over time to detect user hand gestures.

Abstract: A radar apparatus for obtaining a higher range resolution than conventional radar apparatus without increasing the bandwidth comprises a transmitter antenna that transmits a frequency modulated transmit signal having a transmit bandwidth and a receiver antenna that receives a receive signal reflected from said scene in response to the transmission of said transmit signal. A mixer mixes said receive signal with said transmit signal to obtain a mixed receive signal, a sampling unit samples said mixed receive signal to obtain receive signal samples from a period of said receive signal, and a processor processes said receive signal samples by defining a measurement matrix and determines the positions of one or more targets of the scene by applying compressive sensing using said measurement matrix and said receive signal samples. A post-processor groups together receive signal samples having a depth within the same depth bin and belonging to the same target.

Abstract: A method for estimating a target direction of a wideband signal received on an electronically steered array includes: applying convolutional or stretch processing to spatial frequency data of the wideband signal; initializing a stabilization direction to a beam pointing direction; stabilizing the spatial frequency data to the stabilization direction; compressing the spatial frequency data to a plurality of frequency range or time bins; selecting range or time bins and forming a covariance matrix; calculating an estimated target direction using the covariance matrix; determining if a stabilization direction accuracy condition is met; recalculating the stabilization direction based on the estimated target direction if the stabilization direction accuracy condition is not met; and iteratively repeating until the stabilization direction accuracy condition is met.

Abstract: A communications device may include a wireless receiver, and a processor coupled to the wireless receiver. The processor may be configured to receive a spread OFDM signal having narrowband interference associated with the same, the spread OFDM signal having subcarriers with data distributed among the subcarriers. The processor may be configured to excise the narrowband interference from the spread OFDM signal, and despread the spread OFDM signal after excising and based upon the excising to recover the data.

Abstract: A method for classifying vehicles in which an angle-resolving radar device yields measurement signals which have frequencies corresponding to a Doppler shift and which originate from measured vehicles and from which radial distances, object angles and radial velocities can be derived. The frequencies of the acquired measurement signals are stored as functions over the measurement time period, and a spectrogram is formed for every vehicle therefrom. Subsequently, the spectrograms are checked for assessment regions with maximum bandwidth of the frequency. These assessment regions are compared with assessment regions of stored spectrograms for different vehicle classes and associated with the most similar such that the measured vehicles are classified.

Abstract: An altimeter system is provided. The altimeter system includes a receiver mixer including an antenna-input and a local-oscillator-input; a transceiver circulator communicatively coupled to an antenna via a transmission line having a selected length and communicatively coupled to the antenna-input of the receiver mixer; and a transmitter configured to output a transmitter signal to the antenna via the transceiver circulator. The transmitter signal is frequency modulated with a linear ramp. The transmitter is communicatively coupled to the receiver mixer to input a local oscillator signal at the local-oscillator-input of the receiver mixer. The receiver mixer is communicatively coupled to input a target-reflected signal from the antenna at the antenna-input of the receiver mixer. The selected length of the transmission line is set so that a composite-leakage signal at the antenna-input of the receiver mixer has a linear phase across a sweep bandwidth.

Abstract: A radar system in an autonomous vehicle may be operated in various modes and with various configurations. In one example, the radar system determines a target range for further interrogation. The target range may be determined based on the radar system transmitting a first electromagnetic radiation signal and receiving a first reflected electromagnetic signal radiation signal. After the radar system determines a target range, it transmits an electromagnetic radiation signal according to a Frequency Modulated Continuous-wave (FMCW) operating mode. Additionally, the radar system receives a reflected electromagnetic signal radiation based on the transmission. After receiving the reflected signal, the radar system can process the reflected signal to only have components associated with the target range. The processing of the reflected signal may create a processed signal. Finally, the radar system may determine at least one parameter of a target object based on the processed signal.

Abstract: Using a radar system in a motor vehicle, high frequency individual signal pulses are transmitted from at least one transmitting antenna, and at least one receiving antenna receives reception signals formed by reflection of the transmitted signal pulses from objects in the surroundings. The reception signals are mixed with the high-frequency signal to produce low-frequency mixed signals representing the sequence of individual signal pulses. The phase angle of the mixed signals is varied over successive individual signal pulses thereof by varying the phase angle of: the successive individual transmitted signal pulses, the high-frequency signals used for the mixing, and/or the mixed signals. In further processing of the mixed signals to determine the distance and the relative velocity of detected objects, an interference component can be separated and/or suppressed from a useful signal component because the useful signal component has the known phase angle variation but the interference component does not.

Abstract: A method of compensating for transmitter instability of a radar system is provided. The method includes the steps of transmitting at least one electromagnetic pulse and directly measuring at least one characteristic of the transmitted pulse. A comparison is made between the at least one measured characteristic of the transmitted pulse to a reference pulse characteristic. The results of this comparison are used to generate a complex weight for the at least one electromagnetic pulse. The weight is applied to the received return of the at least one electromagnetic pulse.

Abstract: This disclosure provides a radar signal processing device, which includes an amplitude value change determiner for determining, among amplitude values of a series of reception data, an increase/decrease tendency of a predetermined number of amplitude values of the reception data, and a filter processor for filtering the reception data based on the determination result.

Abstract: A method of determining a filling level comprising transmitting a first transmit signal exhibiting a first ratio between bandwidth number of frequencies; receiving a first reflection signal; mixing the first transmit signal and the first reflection signal to form a first intermediate frequency signal; and determining a first data set indicative of a first set of surface echo candidates based on the first intermediate frequency signal. The method further comprises transmitting a second transmit signal exhibiting a second ratio between bandwidth and number of frequencies being different from the first ratio; receiving a second reflection signal; mixing the second transmit signal and the second reflection signal to form a second intermediate frequency signal; and determining a second data set indicative of a second set of surface echo candidates based on the second intermediate frequency signal. The filling level determined based on subsets of the first and second sets.

Abstract: The present invention relates to an object detection system and method for determining range and velocity of a target object by transmitting a frequency modulated continuous wave transmission signal and receiving transmission signal reflections of the transmission signal from the target object as a reception signal. Each modulation block of the transmission signal comprises a number of first type chirps, each first type chirp having a first slope, and a number of second type chirps, each second type chirp having a second slope different from the first slope. Two consecutive chirps of the same type have a frequency offset A mixed signal based on the transmission signal and the reception signal and using the first type chirps and the second type chirps is processed, in order to determine the range and velocity of the target object.

Abstract: System and method for determining the distance between a radio beacon and a vehicle device passing in the radio beacon, in a road toll system. A signal having a known temporal profile is emitted by one of the radio beacon and vehicle device. The signal is captured in the other component during the passing of the device and the temporal profile of the frequency is recorded in relation to the known temporal profile; a modification in the recoded frequency profile exceeding a first threshold value is detected; two distant wave zones in the frequency profile, lying temporally in front of and behind the detected modification are determined, the zones displaying a frequency modification below a second threshold value are searched for; the recorded frequency profile is scaled in such a way that the distant wave zones take the predetermined values; and the distance is determined from the scaled frequency profile.

Abstract: Systems and methods for allowing dual-mode radar operation. An exemplary transmission system includes a hybrid coupler that receives a signal produced by a synthesizer and couples the received signal to two output ports. A pulse transmitter receives a pulse transmit-activate signal from a controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received signal based on a predefined desired pulse output transmission setting. A frequency-modulation continuous-wave (FMCW) transmitter receives an FMCW transmit-activate signal from the controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received input signal based on a predefined desired FMCW output transmission setting. An isolator protects the pulse transmitter during FMCW operation and also the FMCW transmitter from receiving power reflected off of pulse transmitter components.

Abstract: An apparatus for detecting a target in near field in accordance with an exemplary embodiment of the present invention includes: an RF transceiver configured to generate a transmitting signal of a frequency modulated continuous wave (FMCW) and delay the signal as much as a desired time; a transmitting and receiving antenna unit configured to transmit and receive the a transmitting signal and the received signal; and a signal processing unit configured to extract a range or a velocity of the target from the signal provided from the RF transceiver.

Abstract: One embodiment is directed to a method for operating a radar altimeter. The method includes transmitting a radar signal at a first frequency, ramping the frequency of the radar signal from the first frequency to a second frequency, and transmitting the radar signal at the second frequency. The reflections can be processed by determining an approximate distance to a target based reflections of the frequency ramp and the approximate distance can be refined based on a phase difference between a reflection of the radar signal transmitted at the first frequency and a reflection of the radar signal transmitted at the second frequency.

Abstract: A detection and ranging apparatus includes a probe signal generating unit that generates a probe signal according to a first modulation method, a transmitting unit that transmits the generated probe signal, a receiving unit that receives a signal including at least one of a reflection signal and an interference signal according to a second modulation method, a demodulating unit that demodulates the reception signal according to a method corresponding to at least one of the first modulation method and the second modulation method, an interference signal detecting unit that detects the interference signal from the demodulated signal, an interference signal identifying unit that identifies specifications and a delay amount of the interference signal from the demodulated signal, and an interference signal removing unit that removes the interference signal within the reception signal by using the identified specifications and the identified delay amount of the interference signal.

Abstract: Distance between two radio frequency devices is estimated by receiving a plurality of spread spectrum chirp signals frequency offset from one another, and evaluating the received plurality of spread spectrum chirp signals for relative phase shifts between the plurality of spread spectrum chirp signals. A fine propagation time is derived using the phase shifts between the spread spectrum chirp signals. A frequency domain despreading window is shifted to reduce the influence of time-delayed near multipath signals in receiving the plurality of spread spectrum chirp signals.

Abstract: A radar system (100) is described including a transmitting assembly (10), a receiving assembly (20), a control unit (30) and a signal processing unit (40). The transmitting assembly (10) receives an input signal (31) and transmits an incident radar signal (2). The transmitting assembly (10) includes a Rotman lens (12) having a lens cavity (74), a plurality of beam ports (60), a plurality of array ports (62) and a patch antenna assembly (14). The lens cavity (74) has a lens gap (h) between 10 microns to 120 microns, and preferably 40 microns to 60 microns. The patch antenna assembly (14) includes a plurality of antenna arrays (130) operable to receive a plurality of time-delayed, in-phase signals from the Rotman lens (12) and to transmit the incident radar signal (2) towards a target (4). The receiving assembly (20) receives a reflected radar signal (6) and produces an output signal.

Abstract: A radar apparatus for obtaining a higher range resolution than conventional radar apparatus without increasing the bandwidth comprises a transmitter antenna that transmits a frequency modulated transmit signal having a transmit bandwidth and a receiver antenna that receives a receive signal reflected from said scene in response to the transmission of said transmit signal. A mixer mixes said receive signal with said transmit signal to obtain a mixed receive signal, a sampling unit samples said mixed receive signal to obtain receive signal samples from a period of said receive signal, and a processor processes said receive signal samples by defining a measurement matrix and determines the positions of one or more targets of the scene by applying compressive sensing using said measurement matrix and said receive signal samples.

Abstract: The invention relates to a method for determining the distance between a radio beacon and a vehicle device passing in front of said radio beacon, in a road toll system. A signal of a frequency having a known temporal profile is emitted. Said method consists of the following steps: the signal is captured in the other component when passing and the temporal profile of the frequency is recorded in relation to the known temporal profile; a modification in the recorded frequency profile exceeding a first threshold value is detected; two distant wave zones in the frequency profile, lying temporally in front of and behind the detected modification, which displays a frequency modification below a second threshold value, are searched for; the recorded frequency profile is scaled in such a manner that the distance wave zones take the predetermined values; and said distance “a” from the scaled frequency path is determined.

Abstract: The present disclosure relates to the field of pulse compression in signal processing, and more particularly, to systems and methods for the synthesis of waveforms for suppressing sidelobes and sidebands using a combination of time and spectral control. More specifically, the present disclosure relates to a set of waveform symbols which can be used to maximize use of disaggregated grey-space spectrum, adapt to changing spectral condition, and maintain or enhance data rates relative to standard binary phase-shift keying (BPSK) under normal conditions.

Abstract: Disclosed is a radar apparatus supporting short range and long range radar operations, wherein a plurality of short range transmitting chirp signals and a plurality of long range transmitting chirp signals are generated by a predetermined modulation scheme and is transmitted to an object through at least one transmitting array antenna and signals reflected from the object is received through at least one receiving array antenna, and the plurality of long range transmitting chirp signals have transmission power larger than that for the plurality of short range transmitting chirp signals.

Abstract: A method of using a directional sensor for the purposes of detecting the presence of a vehicle or an object within a zone of interest on a roadway or in a parking space. The method comprises the following steps: transmitting a microwave transmit pulse of less than 5 feet; radiating the transmitted pulse by a directional antenna system; receiving received pulses by an adjustable receive window; integrating or combining signals from multiple received pulses; amplifying and filtering the integrated receive signal; digitizing the combined signal; comparing the digitized signal to at least one preset or dynamically computed threshold values to determine the presence or absence of an object in the field of view of the sensor; and providing at least one pulse generator with rise and fall times of less than 3 ns each and capable of generating pulses less than 10 ns in duration.

Abstract: One embodiment is directed towards a FMCW radar having a single antenna. The radar includes a transmit path having a voltage controlled oscillator controlled by a phase-locked loop, and the phase-locked loop includes a fractional-n synthesizer configured to implement a FMCW ramp waveform that ramps from a starting frequency to an ending frequency and upon reaching the ending frequency returns to the starting frequency to ramp again. The radar also includes a delay path coupled between a coupler on the transmit path and a mixer in a receive path. The delay path is configured to delay a local oscillator reference signal from the transmit path such that the propagation time of the local oscillator reference signal from the coupler to the mixer through the delay path is between the propagation time of signal reflected off the antenna and the propagation time of a leakage signal through a circulator.

Abstract: In a radar apparatus, a peak extractor performs frequency analysis on a beat signal to obtain a frequency spectrum for each of first and second detection modes based on the beat signal for a corresponding one of the first and second detection modes. The peak extractor extracts a plurality of first peak-signal components from the frequency spectrum obtained for the first detection mode, and a plurality of second peak-signal components from the frequency spectrum obtained for the second detection mode. A determiner compares each of the plurality of first peak-signal components with a corresponding one of the plurality of second peak-signal components to deter mine whether a noise is included in the beat signal according to a result of the comparison.

Abstract: A method for estimating the position and the speed of a target with a radar is provided. The radar emits a waveform including a train of pulses, each pulse having an OFDM chip constructed from subcarriers, the subcarriers covering the whole bandwidth of the radar. Upon receipt of the echoed pulses, some of the subcarriers are used in a step of Doppler processing, each of the subcarriers being fixed over the pulses. Upon receipt of the echoed pulses, other subcarriers, which are not used for Doppler processing, are used in a step of High Range Resolution processing, the subcarriers being randomly distributed over the pulses.

Abstract: Provided is an object identification device and a method for the same that are capable of identifying a three-dimensional object and a road surface static object, irrespective of situations. The object identification device identifies an object, based on a transmission signal and a reflection signal caused by the object reflecting the transmission signal. The object identification device includes: a measurement section configured to measure at least one of the relative distance and the relative velocity with respect to the object; an intensity detection section configured to detect the intensity of the reflection signal; and an object identification section configured to identify the object which can be an obstacle object, based on at least one of the relative velocity and the variation in the relative distance, and on the variation in the intensity.

Abstract: There is provided a radar apparatus capable of extracting a peak signal obtained from a difference frequency between a transmitting signal and a receiving signal during first and second periods and deriving target information based on the extracted peak signals. A predicting unit derives a predicted peak signal obtained by predicting a current peak signal based on the peak signal obtained in a previous process. An extracting unit extracts a peak signal included within a predetermined frequency range, with the predicted peak signal being as a base point, in each of the first and second periods. A pairing unit pairs the peak signals extracted in the first and second periods. The pairing unit changes a pairing method according to the number of the peak signals extracted in each of the first and second periods.

Abstract: An electronic scanning radar apparatus mounted on a moving object includes a receiving unit including a plurality of antennas receiving a received wave arriving from a target having reflected a transmitted wave, a beat signal generating unit generating a beat signal from the transmitted wave and the received wave, a frequency resolving unit resolving the beat signal in beat frequencies and to calculate complex data based on the beat signal resolved for each beat frequency, and an azimuth detecting unit calculating a direction of arrival of the received wave based on original complex data calculated based on the beat signal, wherein the azimuth detecting unit includes a data extending unit generating extended complex data by extending the number of data based on the original complex data, and a first computation processing unit calculating the direction of arrival of the received wave based on the extended complex data.

Abstract: A method for lessening disturbances of a measurement signal in a radar unit for distance measurement by means of frequency-modulated radar in continuous wave operation. The method comprises steps of: registering, in a reference measurement, a reference signal as a function of time; deriving an error correction signal from the registered reference signal, wherein the error correction signal predominantly comprises spectral components caused or influenced by device-specific defects of the radar unit; registering a measurement signal; and correcting the measurement signal in accordance with the error correction signal by means of digital signal processing.

Abstract: A radar apparatus for obtaining a higher resolution than conventional SAR apparatus without increasing the bandwidth comprises a transmitter antenna and a receiver antenna. A mixer mixes said receive signal with said transmit signal to obtain a mixed receive signal, and a sampling unit samples said mixed receive signal to obtain receive signal samples from a period of said receive signal. A processor processes said receive signal samples by defining a spatial grid in the scene with a finer grid resolution than obtainable by application of a synthetic aperture radar algorithm on the receive signal samples and determining reflectivity values at grid points of said spatial grid by defining a signal model including the relative geometry of said transmitter antenna and said receiver antenna with respect to the scene, said transmit signal and said spatial grid and applying compressive sensing on said receive signal using said signal model.

Abstract: An FMCW radar sensor system is described having an antenna covered by a radome, a mixer for mixing a frequency-modulated transmission signal with a signal received by the antenna, a device for recording the mixed product of the mixer as a time-dependent signal, a device for calculating the spectrum of the time-dependent signal, and a device for detecting a reflecting coating on the radome, characterized in that the device for detecting the reflecting coating is configured for analyzing the time-dependent signal and for determining the extent of reflection on the radome based on the amplitude of this signal.

Abstract: A system and method for detecting dangerous objects and substances are disclosed. According to one embodiment, a method comprises generating a microwave signal that is reflected by a target to render one or more reflected signals. The one or more reflected signals are received at an antenna array. The one or more reflected signals are converted into digital reflected signals. The microwave signal is converted into a digital signal. The digital reflected signals and the digital signal are processed to determine the three dimensional position of the target. The digital reflected signals and the digital signal are processed to identify the target. The digital reflected signals and the digital signal are processed to determine a state of the target; and determine whether the target a dangerous object.

Abstract: A radar sensor for motor vehicles, having a transmitting part, which has two oscillators and a 90° phase shifter for generating a transmission signal, a first comparison signal, and a second comparison signal, which is phase shifted by 90° with respect to the first comparison signal, and a receiving part having an I mixer for mixing a received signal with the first comparison signal and a Q mixer for mixing the received signal with the second comparison signal, in which the transmitting part has a first transmit mixer, whose inputs are directly connected to the two oscillators, and a second transmit mixer, whose one input is directly connected to a first of the two oscillators and whose other input is connected via the phase shifter to the other oscillator.

Abstract: There is provided a radar apparatus for detecting a target. A detection signal generating unit generates detection signals of the target based on transmission and reception waves of antennas. A detection signal processing unit performs frequency analysis on the detection signals to extract signal components of the target, and performs a predetermined process on the signal components to calculate at least one of a distance to the target, a relative speed to the target, and an orientation of the target. The detection signal generating unit includes a filter unit for giving changes to the detection signals in a frequency bandwidth higher than Nyquist frequency which is a half a sampling frequency. The detection signal processing unit acquires the signal components from the detection signals to which the filter unit gives the changes to determine whether the signal components are generated by replication due to the Nyquist frequency.

Abstract: Provided is a radar device capable of preventing mispairing from occurring, and obtaining a distance to a target and a relative velocity to the target even if at least one of the peak frequencies of beat signals cannot be extracted and pairs of the peak frequencies cannot be generated. A target estimation part (20) estimates a distance (RN) to a target (21, 22) and a relative velocity (VN) to the target (21, 22) based on a distance (RO) to the target (21, 22) and a relative velocity (VO) to the target (21, 22), which have been decided by a target decision part (13) in a previous cycle, when at least one of the peak frequencies of the beat signal cannot be extracted and the pair of the peak frequencies cannot be generated.

Abstract: This disclosure provides a range side lobe removal device, which includes a pulse compressor for acquiring a reception signal from a radar antenna and generating a pulse-compressed signal by performing a pulse compression of the reception signal, a pseudorange side lobe generator for generating a pseudo signal of range side lobes of the pulse-compressed signal based on the reception signal, and a signal remover for removing a component corresponding to the pseudo signal from the pulse-compressed signal.

Abstract: There is provided a radar apparatus configured to emit a transmission wave, to receive a reflected wave as a reception signal, and to derive target information including at least position information of a target from peak signals which are extracted by performing FFT processing for a beat signal that is generated from the reception signal. A determination unit is configured to determine whether a specific peak signal exists at a frequency that is distant from a frequency of the peak signal existing at a first frequency by a frequency of one selected peak signal selected from the plurality of peak signals. An exclusion unit is configured to exclude the target information corresponding to the selected peak signal from an output object of the radar apparatus when the specific peak signal exists.

Abstract: A method and a radio beacon for determining a distance of a vehicle passing a radio beacon of a road toll system, from beacon. The vehicle is equipped with an onboard unit, which emits a signal with a known curve of its frequency over time. The method includes receiving the signal in the radio beacon during passage of the vehicle and recording a curve of its frequency over time in relation to the known frequency curve; detecting a change in the recorded frequency curve exceeding a predetermined threshold value; looking for two far regions in the frequency curve lying before and after the detected change in time and showing a frequency change below a threshold value; scaling the recorded frequency curve in such a manner that the far regions assume predetermined values; and determining the said distance from a gradient of the scaled frequency curve in an inflection point thereof.

Abstract: There is provided a radar apparatus. An extracting unit extracts a peak signal obtained from a difference frequency between a transmitting signal and a receiving signal during a first period in which the frequency of the transmitting signal ascends and a second period in which the frequency descends. A pairing unit pairs the peak signals of the first and second periods based on a predetermined condition. A deriving unit derives target information including a position of a target based on paired data obtained by pairing the peak signals. The pairing unit selects normal-paired data which is paired in a correct combination, from among the plurality of paired data, based on a plurality of parameter values of the peak signals of the first and second periods which are to be paired, and a discrimination function for discriminating true or false of the pairing.

Abstract: Methods and systems for post processing synchronization of bistatic radar data are disclosed. A transmitter is configured to transmit pulses at a first rate controlled by a first local oscillator. A receiver is configured to receive pulses at a second rate controlled by a second oscillator. A processing device is configured to synchronize, with respect to the first rate, in-phase quadrature data received from the receiver using a keystone formatting technique.

Abstract: Presented is a method for determining speeds (vr14, vr16) and distances (r14, r16) of objects (14, 16) relative to a radar system (12) of a motor vehicle (10), wherein a coverage area (EB) of the radar system (12) is divided into at least two part-areas (TB1, TB2, TB3), the coverage area (EB) is examined for reflecting objects (14, 16) in successive measuring cycles (MZ1, MZ2; MZi, MZi+1), wherein radar signals received in a measuring cycle (MZ1, MZ2; MZi, MZi+1) are processed separated in accordance with part-areas (TB1, TB2, TB3) and processed signals are assembled to form a total result differentiated in accordance with spatial directions. The method is characterized in that from signals received in a first measuring cycle (MZ1; MZi), hypotheses for the distance (r14, r16) and speed (vr14, vr16) of reflecting objects (14, 16) are formed and the hypotheses are validated in dependence on signals received in at least one further measuring cycle (MZ2; MZi+2).

Abstract: A DDS based system, such as a radar, includes means for generating a plurality of transmission signals using a DDS, and means for integrating signals derived therefrom, such as received signals. The system further includes means for varying the relative starting phase of the plurality of transmission signals, or adjusting the DDS input clock while maintaining similar primary output frequency characteristics of the transmission signals. The approach has the effect of changing the location of unwanted frequency spurs in each of the transmission signals, and hence the effects of these are decreased in the integration process. An improvement in the sensitivity of the system results. Although primarily suited to radar applications the invention may find utility in other systems such as sonar or lidar systems.

Abstract: The invention provides a security scanner that produces a radar profile of a clothed person or another object such as a bag carried by a person at a distance and does not require close proximity of the person or object to the scanner itself. The scanner includes a millimeter wave antenna system optimised for short-range active imaging and arranged to provide rapid high-resolution images of an object or person of interest and processing means for resolving the images so as to detect the presence of predetermined objects. The processing means preferably includes means for comparing contrasts in reflectivity in the scanned images with predetermined expected values from skin and light clothing. The processing means may also include means for detecting predetermined behavioral or physical traits such as the effect on gait on carried weighty objects or stiff structures strapped to the person from the images of a scanned object or person. The scanner may be incorporated within a turnstile access arrangement.

Abstract: Disclosed is a distance measuring apparatus which includes: a first pulse generating means (135) which generates reference signals; a second pulse generating means (137) which generates subject detection signals; a time measuring section (139) which measures a period of time from a time when a first pulse is generated to a time when a second pulse is generated; a first phase detecting section (141) which detects the first phase of a signal received using a signal at a first frequency; a second phase detecting section (163) which detects the second phase of a signal received using a signal at a second frequency; and a distance calculating section (165) which calculates the distance to the subject on the basis of output from the time measuring section, the first phase detecting section and the second phase detecting section.

Abstract: A signal processing device performs object detection processing in which peak signals each representing a differential frequency between a transmitted signal in which a frequency thereof changes in a predetermined cycle and a received signal are derived in a first period where the frequency of the transmitted signal rises and a second period where the frequency of the transmitted signal falls, and the peak signals in the first period are paired with the peak signals in the second period to detect object information related to the peak signals. A range setting unit sets a frequency range in each of the first period and the second period on the basis of a frequency of an integer multiple of the peak signal related to the object information which has been detected in previous object detection processing. A signal setting unit sets a peak signal as a specific peak signal in a case where the peak signal is within the frequency range in each of the first period and the second period.

Abstract: A radar apparatus for obtaining a higher range resolution than conventional radar apparatus without increasing the bandwidth comprises a transmitter antenna that transmits a frequency modulated transmit signal having a transmit bandwidth and a receiver antenna that receives a receive signal reflected from said scene in response to the transmission of said transmit signal. A mixer mixes said receive signal with said transmit signal to obtain a mixed receive signal, a sampling unit samples said mixed receive signal to obtain receive signal samples from a period of said receive signal, and a processor processes said receive signal samples by defining a measurement matrix and determines the positions of one or more targets of the scene by applying compressive sensing using said measurement matrix and said receive signal samples. A post-processor groups together receive signal samples having a depth within the same depth bin and belonging to the same target.

Abstract: A wireless ranging system for determining a range of a remote wireless device may include a wireless transmitter and a wireless receiver. The wireless ranging system may also include a ranging controller to cooperate with the wireless transmitter and receiver to generate a multi-carrier base waveform, transmit a sounder waveform to the remote wireless device including concatenated copies of the multi-carrier base waveform, and receive a return waveform from the remote wireless device in response to the sounder waveform. The ranging controller may also generate time domain samples from the return waveform, convert the time domain samples into frequency domain data, and process the frequency domain data to determine the range of the remote wireless device.