Fast Fourier Transform (fft) Patents (Class 342/196)
  • Patent number: 7579982
    Abstract: A radar apparatus includes: a plurality of receiving antennas disposed at regular spacings; two transmitting antennas which are positioned each at opposed ends of the receiving antennas, and a spacing of which away from the receiving antennas adjacent thereto is a natural number multiple of half a disposition spacing of the plurality of the receiving antennas; and a signal processor which, after the two transmitting antennas transmit electric waves in time divisions, and then one for each of the plurality of receiving antennas receives waves reflected from a target, subjects the obtained received signals to a digital beam forming process, in which case the signal processor, after subjecting the received signals to a fast Fourier transform process in a time direction, carries out a fast Fourier transform process in a space direction.
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: August 25, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventor: Katsuji Matsuoka
  • Patent number: 7579981
    Abstract: Disclosed is a signal processing method for an FM-CW radar that can accurately detect the relative distance, relative velocity, etc. with respect to a target approaching or receding at a high relative velocity, wherein predicted values for peak frequencies currently detected in upsweep and downsweep sections are computed from the previously detected relative distance and relative velocity, and it is determined whether any of the predicted values exceeds a detection frequency range and, if there is a peak frequency that exceeds the detection frequency range, the frequency is folded and the folded frequency is taken as one of the predicted values, the method then proceeding to search the currently detected peak frequencies to determine whether there are upsweep and downsweep peak frequencies approximately equal to the predicted values and, if such upsweep and downsweep peak frequency are found, the peak frequency approximately equal to the folded predicted value is folded and the folded peak frequency is used.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: August 25, 2009
    Assignee: Fujitsu Ten Limited
    Inventor: Masayuki Kishida
  • Patent number: 7576688
    Abstract: Moving objects are detected with a radar by collecting samples of a received signal over an integration period. The terms of a match function contain a product of a sample of said received signal and a delayed-in-time, Doppler-shifted replica of a transmission and depend on parameters that describe an object that caused a reflection of the transmission. The most probable values of the parameters are found by maximizing the match function through Fourier transforming a vector consisting of terms of the match function. Those of said products that contain a non-zero contribution of said delayed-in-time, Doppler-shifted replica of a transmission are actually computed while the others of said products are zero Only non-zero blocks of the products count as final terms to the vector to be Fourier transformed that have nonzero value while intermittent blocks that have zero value are left out.
    Type: Grant
    Filed: February 20, 2006
    Date of Patent: August 18, 2009
    Assignee: Eigenor Oy
    Inventor: Markku Sakari Lehtinen
  • Publication number: 20090195442
    Abstract: A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveform and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.
    Type: Application
    Filed: February 5, 2008
    Publication date: August 6, 2009
    Inventors: Jeremy Francis Burri, Michael Howard Farris, Matthew Michael Pohlman, Randall Edward Potter
  • Patent number: 7570200
    Abstract: In the invention, a four-port junction (10) has a port (12) connected to an RF signal source (14). The four-port junction (10) also has an antenna port (16) coupled to a combined transmit/receive antenna (18). Two ports (20, 22) of the four-port junction (10) develop output power that is applied to an analogue-to-digital converter (24), that is in turn coupled to a central processor (26), that is in turn coupled to a user interface (28).
    Type: Grant
    Filed: January 12, 2006
    Date of Patent: August 4, 2009
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventor: Joshua D. Niedzwiecki
  • Patent number: 7570197
    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.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: August 4, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Kazuaki Takano, Jiro Takezaki, Hiroshi Kuroda, Hiroshi Kondo
  • Patent number: 7567202
    Abstract: Embodiments of the invention are concerned with a radar system, and relates specifically to scanning radar systems that are suitable for detecting and monitoring ground-based targets.
    Type: Grant
    Filed: May 19, 2008
    Date of Patent: July 28, 2009
    Assignee: Plextek Limited
    Inventors: Graham Pearson, Steve Greendale, David Spreadbury
  • Patent number: 7567198
    Abstract: Embodiments of methods, apparatuses, and articles for receiving phase history data collected from synthetic aperture radar imaging of a terrain, dividing the received phase history data into a plurality of subsets corresponding to a plurality of subaperture intervals, computing for each of a plurality of points of the terrain, a contribution of each of the plurality of subaperture intervals, each contribution including a magnitude and a phase calculated by interpolating the subaperture interval, using the corresponding subset of phase history interval data, and based at least in part on an arbitrary reference surface's elevation at the point, summing for each of the plurality of points of the terrain, the contributions of the plurality of subaperture intervals, and forming an image of the terrain based at least in part on the summed contributions of the plurality of subaperture intervals to the plurality of points of the terrain, are described herein.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: July 28, 2009
    Assignee: The Boeing Company
    Inventor: Brian H. Smith
  • Patent number: 7567204
    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.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: July 28, 2009
    Assignee: DENSO CORPORATION
    Inventor: Mai Sakamoto
  • Patent number: 7567206
    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.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: July 28, 2009
    Assignee: Robert Bosch GmbH
    Inventors: Ewald Schmidt, Klaus Voigtlaender
  • Patent number: 7561100
    Abstract: A correlation processor for a receiver is capable of carrying out a correlation process with highly suppressed side lobes, improved resolution, and minimized S/N loss. The correlation processor is provided for a receiver that receives a signal having a specific time width and shape, for carrying out a correlation process on the received signal. The correlation processor has a filter coefficient unit to calculate a coefficient vector that zeroes sample values of all sample points except a peak center sample point of a main lobe of a correlation-processed waveform of the received signal and sample points on each side of the peak center and minimizes S/N loss of the sample value of the peak center sample point of the main lobe and a filter to carry out a correlation process on the received signal according to the coefficient vector calculated by the filter coefficient unit.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: July 14, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Mitsuyoshi Shinonaga
  • Patent number: 7555169
    Abstract: An image noise reduction method in frequency domain is provided, comprising selecting a first image and applying a Fourier transform thereon to acquire a first frequency spectrum, wherein each pixel of the first frequency spectrum has a real part X and a imaginary part Y, calculating a first energy of each pixel and a first mean energy of all first energies of the pixels, calculating a first mean value and a first standard deviation of the real part of the pixels, calculating a second mean value and a second standard deviation of the imaginary part of the pixels, determining a first and a second predetermined values, when the first energy exceeds the first mean energy, the first and second predetermined value are replaced with X and Y, and when the first energy does not exceed the first mean energy, X and the Y are reserved.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: June 30, 2009
    Assignee: Lite-On Technology Corporation
    Inventor: Keven Yang
  • Patent number: 7551118
    Abstract: A filter scheme for broadcast interference cancellation that is computationally efficient and numerically robust Airborne Low Frequency Synthetic Aperture Radar (SAR) operating in the VHF and UHF bands has been shown. At least interference Doppler filtering or interference cancellation is utilised. The interference cancellation involves prediction of the interference for each particular reception interval of mixed interference and radar ground response. This prediction is then coherently subtracted from the incoming signal.
    Type: Grant
    Filed: April 26, 2004
    Date of Patent: June 23, 2009
    Assignee: Saab AB
    Inventor: Hans Hellsten
  • Patent number: 7548191
    Abstract: In order to enable intermittent output of an oscillation signal without essentially producing a leak in response to a pulse signal indicating a transmission timing of a radar wave, a radar oscillator is provided which employs a configuration in which an operation of an oscillating unit itself is alternately changed between an oscillating state and an oscillation stop state by a switch, rather than a configuration in which an output passage of an oscillation signal is switched to be opened and closed as in a conventional radar oscillator.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: June 16, 2009
    Assignees: Anritsu Corporation, Matsushita Electric Industrial Co., Ltd.
    Inventors: Yutaka Arayashiki, Sumio Saito, Masanori Ejima
  • Patent number: 7548193
    Abstract: For enabling determination on whether a sign of a Doppler frequency or a target angle is positive or negative even when only a real signal can be obtained as a received signal, the present invention provides a radar device including: an oscillator; a transmitting element; a distributor; receivers using the local wave to detect the received wave to generate a real received signal; a plurality of inter-channel phase correcting units; a spatial frequency information generating unit for converting a received signal string obtained by gathering a plurality of phase-corrected received signals into a signal in a spatial frequency domain; and a sign selecting unit for selecting a signal having a larger amplitude in a spatial frequency spectrum when two signals from a positive direction and a negative direction which are symmetrical with respect to a direction at approximately 0 degree.
    Type: Grant
    Filed: October 15, 2007
    Date of Patent: June 16, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshio Wakayama, Masashi Mitsumoto, Naohisa Uehara
  • Patent number: 7538712
    Abstract: A computer system for decompressing synthetic aperture radar (SAR) images includes a database for storing SAR images to be decompressed, and a processor for decompressing a SAR image from the database. The decompressing includes receiving the SAR image, performing a dynamic range compression on the SAR image, and quantizing the compressed SAR image. The quantized compressed SAR image is then decompressed by applying an anistropic diffusion algorithm thereto.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: May 26, 2009
    Assignee: Harris Corporation
    Inventors: Josef Allen, Emile Ganthier, Mark Rahmes, Matthew Winter
  • Patent number: 7538720
    Abstract: A transmit signal is output from a transmitter towards a target and towards interference. A combination signal is received at a receiver, wherein the combination signal includes the transmit signal modified by interacting with the target and the interference along with noise. The receiver has a filter having a transfer function and the filter acts on the combination signal to form a receiver output signal having a receiver output signal waveform. The receiver output signal has a receiver output signal waveform that describes an output signal to interference to noise ratio (SINR) performance. Bandwidth and signal energy of the transmit signal are reduced simultaneously by modifying the transmit signal waveform and receiver output signal waveforms without sacrificing the output SINR performance level.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: May 26, 2009
    Assignee: C & P Technologies, Inc.
    Inventor: Unnikrishna Sreedharan Pillai
  • Publication number: 20090128400
    Abstract: A radar device (100) comprising transmit and receive parts, and a control unit (CU). The transmit part includes means (WG) for generating a signal within a certain band, and the receive part comprises a filter (AAF), an AD-converter (ADC) and a Fourier transform unit (FFT1). The transmit part generates a group of signals, each having a first bandwidth between a first and a second frequency, in such a way that a larger bandwidth (B1-B4) is covered by the group. The receive part is open over said larger bandwidth (B1-B4) during reception of each signal in said group, and the transmit part comprises means (PAD, FFT2) for creating FFT-copies of the received signals and means (CONJ) for creating conjugates of said copies. The receive and transmit parts comprise means (EXTR) for extracting data from the FFT from the first bandwidth covered by a received signal, and the radar device comprises means (DIFF) for correlating said extracted FFT-data.
    Type: Application
    Filed: May 31, 2005
    Publication date: May 21, 2009
    Inventors: Hans Hellsten, Nils Dagas, Torbjorn Elfstrom
  • Patent number: 7535409
    Abstract: A time-reversal imaging radar system for acquiring an image of a remote target includes an antenna array having a plurality of spaced-apart antennas, and a transceiver coupled to the antenna array for alternately transmitting a radar signal via the antenna array toward the target and for receiving target-reflected radar signals. The transceiver includes means for multiple-pass time-reversing the transmitted and received radar signals whereby coherent beam focusing is realized at both the target and at the receiver to thereby enhance the resolution of the acquired target image.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: May 19, 2009
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Joon Y Choe, Eung Gi Paek
  • Patent number: 7532154
    Abstract: The frequency modulation radar device includes a transmitting unit (5), M receiving units for receiving a reflected signal as M channels, a mixing unit (7) for mixing the transmitting signal with the M received signals to obtain beat signals for the M channels, a frequency analyzing unit (9) for analyzing the beat signals for the M channels in frequency, and a calculating unit (1) for calculating a distance to a target object and an orientation angle based on frequency analysis results. The calculating unit (1) calculates a noise level from the frequency analysis result, extracts a peak signal of a subject target object in each of the channels based on the calculated noise level to generate a covariance matrix, discriminates between a signal eigenvalue and a noise eigenvalue among M eigenvalues of the covariance matrix, and estimates the number of incident signals based on the number of signal eigenvalues.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: May 12, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventor: Shinsaku Noda
  • Patent number: 7532152
    Abstract: An automotive radar system having a high frequency radio transmitter which generates a radar signal in a known direction. A high frequency radio receiver receives echoes from the radar signal in which each echo represents a reflection of the radar signal from an object. A processor then identifies animate objects, if any, from the received echoes within a range of interest and generates an alert signal for each such identified animate object.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: May 12, 2009
    Assignee: Toyota Motor Engineering & Manufacturing North America, Inc.
    Inventor: Serdar H. Yonak
  • Patent number: 7528768
    Abstract: A radar device includes: an oscillator for generating a wave at a plurality of transmission frequencies; a transmitting antenna; a receiving antenna; a receiver for generating a real received signal; a Fourier transform unit for performing a Fourier transform on the real received signal in a time direction; a spectral peak detecting unit for receiving an input of a result of the Fourier transform to extract peak complex signal values of Doppler frequency points having a maximum amplitude; a distance calculating unit for storing the peak complex signal values and for calculating a distance to a reflecting object based on the stored peak complex signal values to output the obtained distance as a measured distance value; and a distance sign determining unit for determining validity of the measured distance value and for outputting the measured distance value and the Doppler frequency according to a result of determination.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: May 5, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshio Wakayama, Takayuki Inaba, Satoru Murayama, Takashi Sekiguchi
  • Patent number: 7522097
    Abstract: A method to compensate for radar platform angular motion may include measuring or estimating any radar platform angular motion. The method may also include substantially decoupling each array subsection response of a plurality of array subsection responses from any radar platform angular motion by applying continuous time varying phase adjustments to each individual array subsection response, prior to forming composite array Sum and monopulse Delta beam responses The time varying phase adjustments may be determined in response to any radar platform angular motion measured or estimated.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: April 21, 2009
    Assignee: The Boeing Company
    Inventor: David R. Wakeman
  • Patent number: 7511659
    Abstract: To provide a radar device which employs fast Fourier transform in a beam combining process to reduce the operation amount, the radar device including: a Fourier transform section that extracts a received signal that is obtained from waves radiated from a same transmitting element and received by a receiving element, and subjects a signal series of the extracted received signal to Fourier transform to generate a signal of a spatial frequency domain; a phase compensation section that compensates the signal of the spatial frequency domain with a phase difference that is caused by a difference between a predetermined reference position and a position of the used transmitting element; and a coherent integration section that adds the signals of the spatial frequency domain after the signals have been subjected to the phase compensation processing, which are obtained with the plurality of transmitting elements, in each of the spatial frequencies.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: March 31, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshio Wakayama, Masashi Mitsumoto
  • Patent number: 7511656
    Abstract: Embodiments of spotlight synthetic aperture radar (SAR) systems and methods generating a SAR map in real time with minimum latency using a modified Polar Format Algorithm are generally described herein. Other embodiments may be described and claimed. In some embodiments, FPGA implemented down-range and cross-range resampling filters generate fully interpolated data which may be FFT processed as it is generated. In some embodiments, the down-range resample filter and the cross-range resample filter are output-based resampling filters that align a sinc function with an output grid and input coordinates define filter coefficients to modulate the input samples. In some embodiments, the down-range and cross-range resample filtering, coordinate generation, timing, address, and control, fully-interpolated data storage and the down-range FFT may be implemented in a single FPGA.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: March 31, 2009
    Assignee: Raytheon Company
    Inventor: Rodney J. Callison
  • Patent number: 7508334
    Abstract: A computer system for processing synthetic aperture radar (SAR) images includes a database for storing SAR images to be processed, and a processor for processing a SAR image from the database. The processing includes determining noise in a SAR image to be processed, selecting a noise threshold for the SAR image based on the determined noise, and mathematically adjusting an anisotropic diffusion algorithm based on the selected noise threshold. The adjusted anisotropic diffusion algorithm is applied to the SAR image.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: March 24, 2009
    Assignee: Harris Corporation
    Inventors: Josef Allen, Emile Ganthier, Mark Rahmes
  • Publication number: 20090073028
    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.
    Type: Application
    Filed: August 13, 2008
    Publication date: March 19, 2009
    Inventors: Orhan Arikan, Ahmet Kemal Ozdemir
  • Patent number: 7504985
    Abstract: Radar systems are disclosed that include a signal generator, an antenna, a switching circuit, an I/Q sampling and signal-demodulation (demodulation) processor, and a FFT processor. The signal generator produces energization signals. The antenna has multiple individual antenna elements. The switching circuit is configured to deliver the energization signals to a selected antenna element at a respective moment in time to cause the selected antenna element to transmit a respective radar signal in response to the energization signal. At least one element receives a corresponding return-radar signal before the switching circuit selects a next antenna element to transmit a respective radar signal. The demodulation processor receives the return-radar signals from the antenna elements and demodulates the return-radar signals. The FFT processor fast-Fourier transforms the return-radar signals.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: March 17, 2009
    Assignee: Board of Regents of the Nevada System of Higher Education on Behalf of the University of Nevada, Reno
    Inventors: James M. Henson, Ross P. Kohlmoos
  • Patent number: 7504989
    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.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: March 17, 2009
    Assignees: Fujitsu Ten Limited, Fujitsu Limited
    Inventors: Masataka Tsuchihashi, Nobukazu Shima, Kazuo Shirakawa
  • Patent number: 7498977
    Abstract: Probing incident radar fields in a target test zone of a RCS test facility by exploiting angular radar response of a long and uniform rigid body supported horizontally across or vertically through the test zone. The rigid body is free to rotate about the broadside condition. Thus, the angle of the rigid body is gradually changed with respect to the direction of arrival of the incident wave. Radar echo from the rigid body is measured as a function of the rigid body angle. The data is then processed to yield a profile of the incident wave intensity along the rigid body. By varying the azimuth angle continuously while recording radar data, the data may be processed by the fast Fourier transform (FFT) algorithm to yield a profile of the incident wave intensity along the rigid body.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: March 3, 2009
    Assignee: The Boeing Company
    Inventors: Pax S. P. Wei, Anthony W. Reed, Craig N. Ericksen, James D. Doty, Robert K. Schuessler
  • Patent number: 7489266
    Abstract: A radar system comprises: a plurality of reception antennas; a transmission wave generating device; a transmission antenna; a mixer; an A/D converter; a storage device which stores the digitized beat signals in association with each of the reception antennas; a Fourier transformation device which Fourier transforms the stored beat signals; a digital beam forming device which generates beam signals at predetermined pitch angles based on the Fourier transformed signals; an orientation detecting device which detects an orientation of the object using the generated beam signals; a distance detecting device which detects a distance to the object using the generated beam signals; and a signal separation processing device which performs separation processing of the beat signals based on the detected orientation and distance of the object, using the beat signals associated with each of the reception antennas, which are Fourier transformed by the Fourier transformation device.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: February 10, 2009
    Assignees: Honda Elesys Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Kensuke Ohtake, Manabu Hirao, Masahito Shingyoji, Hiroyuki Ando
  • Patent number: 7482967
    Abstract: An apparatus for characterising an input signal within abroad frequency band by comparing the same input signal in a plurality of channels, in order to operate digital Electronic Support Measures (ESM) which require a broad bandwidth to function. The apparatus comprises one or more signal input bands spread across the broad frequency band, a means of splitting the input signal in each input band into a plurality of separate channels, and a means of sampling each channel, wherein the sampling means in each channel runs at a different clock rate from sampling means in each of the other channels within the input bands, so as to remove the ambiguities inherent in frequency aliasing.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: January 27, 2009
    Assignee: The Secretary of State For Defence
    Inventor: George Peter Beharrell
  • Patent number: 7479920
    Abstract: A method and apparatus for terrain mapping and/or obstacle detection for aircraft, including (a) transmitting a non-scanning beam that illuminates the terrain and/or obstacles; (b) receiving a Doppler shifted signal that is Doppler frequency shifted by an amount dependent on an angle between a line of flight of the aircraft and scatterers that reflect the transmitted beam; (c) determining the angle from the Doppler frequency; (d) determining the range of at least some of said scatterers; and (e) determining the azimuth and elevation of the scatterers.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: January 20, 2009
    Inventor: Haim Niv
  • Patent number: 7479921
    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.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: January 20, 2009
    Assignees: The University of Tokushima, Nohken Inc.
    Inventors: Tadamitsu Iritani, Kazuhiro Wakabayashi
  • Publication number: 20090009385
    Abstract: Moving objects are detected with a radar by collecting samples of a received signal over an integration period. The terms of a match function contain a product of a sample of said received signal and a delayed-in-time, Doppler-shifted replica of a transmission and depend on parameters that describe an object that caused a reflection of the transmission. The most probable values of the parameters are found by maximizing the match function through Fourier transforming a vector consisting of terms of the match function. Those of said products that contain a non-zero contribution of said delayed-in-time, Doppler-shifted replica of a transmission are actually computed while the others of said products are zero Only non-zero blocks of the products count as final terms to the vector to be Fourier transformed that have nonzero value while intermittent blocks that have zero value are left out.
    Type: Application
    Filed: February 20, 2006
    Publication date: January 8, 2009
    Inventor: Markku Sakari Lehtinen
  • Patent number: 7474255
    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.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: January 6, 2009
    Assignee: Chung Shan Institute of Science and Technology, Armaments Bureau, M.N.D.
    Inventors: Hung-Tao Hsieh, Feng-Ling Liu, Yao-Hwa Wen
  • Publication number: 20080303711
    Abstract: A radar apparatus includes: a plurality of receiving antennas disposed at regular spacings; two transmitting antennas which are positioned each at opposed ends of the receiving antennas, and a spacing of which away from the receiving antennas adjacent thereto is a natural number multiple of half a disposition spacing of the plurality of the receiving antennas; and a signal processor which, after the two transmitting antennas transmit electric waves in time divisions, and then one for each of the plurality of receiving antennas receives waves reflected from a target, subjects the obtained received signals to a digital beam forming process, in which case the signal processor, after subjecting the received signals to a fast Fourier transform process in a time direction, carries out a fast Fourier transform process in a space direction.
    Type: Application
    Filed: February 21, 2008
    Publication date: December 11, 2008
    Applicant: Mitsubishi Electric Corporation
    Inventor: Katsuji MATSUOKA
  • Patent number: 7460058
    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.
    Type: Grant
    Filed: November 2, 2007
    Date of Patent: December 2, 2008
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Motoi Nakanishi
  • Patent number: 7460059
    Abstract: Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: December 2, 2008
    Assignee: Sandia Corporation
    Inventors: Richard C. Ormesher, Robert M. Axline
  • Patent number: 7453398
    Abstract: The invention refers to array antennas consisting of a set of individual sources set out over the surface of the antenna and whose mechanical positioning is determined in such a way as to obtain the desired radiation pattern. The process according to the invention is designed to compensate for the positioning errors of radiating elements occurring when such an antenna is constructed. These positioning errors follow a law that is in theory random and whose result is known by determining the imperfection vector I whose components of real positioning errors measured for each feed of the antenna obtained comprising components forming values of an error function ?(n) where n represents the index attributed to the radiating element in question. The process according to the invention consists in first measuring the positioning errors. It then consists in determining the spatial spectral components making up error function ?(n).
    Type: Grant
    Filed: March 17, 2007
    Date of Patent: November 18, 2008
    Assignee: Thales
    Inventors: Benjamin Rouzeaud, Claude Chekroun, Marc-Yves Lienhart
  • Patent number: 7450057
    Abstract: A method for performing signal processing for accelerating moving targets, in one implementation, encompasses a method for performing coherent integration of pulses within a CPI for SMTI radar. In an embodiment, the method comprises the steps of determining the Fast Fourier Transform (FFT) for each pulse, and multiplying the FFT by a pulse compression reference function.
    Type: Grant
    Filed: October 20, 2006
    Date of Patent: November 11, 2008
    Assignee: Northrop Grumman Space & Missions Systems Corp.
    Inventor: David Charles Clark
  • Patent number: 7450054
    Abstract: A computer system for processing interferometric synthetic aperture radar (SAR) images includes a database for storing SAR images to be processed, and a processor for processing interferometric SAR images from the database. The processing includes receiving first and second complex SAR data sets of a same scene, with the second complex SAR data set being offset in phase with respect to the first complex SAR data set. Each complex SAR data set includes a plurality of pixels. An interferogram is formed based on the first and second complex SAR data sets for providing a phase difference therebetween. A complex anisotropic diffusion algorithm is applied to the interferogram. The interferogram includes a real and an imaginary part for each pixel. A shock filter is applied to the interferogram. The processing further includes performing a two-dimensional variational phase unwrapping on the interferogram after application of the shock filter.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: November 11, 2008
    Assignee: Harris Corporation
    Inventors: Kenneth Sartor, Josef Allen, Emile Ganthier, Bernard S. Gilbert, Gnana Bhaskar Tenali
  • Patent number: 7439905
    Abstract: In a radar apparatus constructed to perform switching between a plurality of receiving antennas by using a switch, the effect of noise induced by the antenna switching is eliminated. A situation where there is no echo signal from a target is created, for example, by turning off a transmitter amplifier, and the Fourier transformed result obtained at this time is taken as a correction value and stored in a memory. During radar operation, the effect of the noise induced by the antenna switching can be eliminated by subtracting the correction value from the Fourier transformed result.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: October 21, 2008
    Assignee: Fujitsu Ten Limited
    Inventors: Kanako Honda, Osamu Isaji
  • Patent number: 7432849
    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.
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: October 7, 2008
    Assignee: Mitsubishi Electric Corporation
    Inventor: Shinsaku Noda
  • Patent number: 7425917
    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.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: September 16, 2008
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Motoi Nakanishi, Toru Ishii
  • Patent number: 7425693
    Abstract: A method of tracking a target. The method includes the steps of acquiring a first spectral image of a scene that includes the target, designating a spectral reference window, in the first spectral image, that includes a respective plurality of pixel vectors, acquiring a second spectral image, of the scene, that includes a respective plurality of pixel vectors, and hypercorrelating the spectral reference window with the second spectral image, thereby obtaining a hypercorrelation function, a maximum of the hypercorrelation function then corresponding to a location of the target in the scene.
    Type: Grant
    Filed: July 18, 2004
    Date of Patent: September 16, 2008
    Assignee: Rafael Advanced Defence Systems Ltd.
    Inventor: Ruth Shapira
  • Publication number: 20080191932
    Abstract: The invention relates to a method for determining a correlation between an unknown first data signal and a known second data signal in a spread spectrum transmission system consisting of a plurality of signal sources, each source being associated with a unique code, for identifying and tracking the source from which said unknown first data signal originates, the method comprising obtaining a first data signal originating from an unknown source of said plurality of sources; subjecting said first data signal to a Fast Fourier Transformation; selecting a code from said plurality of unique codes associated to said sources; generating a known second data signal in accordance with said selected code; subjecting said second data signal to a Fast Fourier Transformation; multiplying said Fast Fourier transformed first and second data signals; subjecting said multiplied data signal to an inverse Fast Fourier Transformation; determining a correlation between said first and second data signals based on said inverse Fast
    Type: Application
    Filed: March 31, 2005
    Publication date: August 14, 2008
    Inventors: Erwin Hemming, Marc Hoffman
  • Patent number: 7411540
    Abstract: A method of compressing phase history (PH) data includes (a) dividing PH data into multiple sub-apertures; (b) transforming the sub-apertures into multiple coarse resolution images; and (c) compressing each of the coarse resolution images. Compressing each of the coarse resolution images may include (i) selecting at least one image from the coarse resolution images to form a base image, (ii) differencing each of the coarse resolution images from the base image to form residual images, and (iii) quantizing the residual images.
    Type: Grant
    Filed: March 10, 2005
    Date of Patent: August 12, 2008
    Assignee: ITT Manufacturing Enterprises Inc.
    Inventors: Norman A. Lopez, Michael T. Mulford
  • Patent number: 7411544
    Abstract: A system for processing radar data from two or more areas of interest is provided, such as for simultaneously processing vehicle speeds in the opposite lane in front of the patrol vehicle and in the opposite lane behind the patrol vehicle. The system includes an antenna signal processor that receives radar data from one or more radar antennae and generates speed data for a first vehicle travelling in a first direction relative to a radar observation point and a second vehicle travelling in a second direction relative to the radar observation point. A display generator system receives the speed data and user-entered display control data, and generates user-readable display data based on the speed data and the user-entered display control data.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: August 12, 2008
    Assignee: Applied Concepts, Inc.
    Inventors: John L. Aker, Alan B. Mead, Robert S. Gammenthaler, Robert Vanman
  • Publication number: 20080174475
    Abstract: A method for performing signal processing for accelerating moving targets, in one implementation, encompasses a method for performing coherent integration of pulses within a CPI for SMTI radar. In an embodiment, the method comprises the steps of determining the Fast Fourier Transform (FFT) for each pulse, and multiplying the FFT by a pulse compression reference function.
    Type: Application
    Filed: October 20, 2006
    Publication date: July 24, 2008
    Inventor: David Charles Clark