Receiver Patents (Class 342/89)
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Patent number: 7417579Abstract: A weather radar system includes processing electronics. The processing electronics sense weather and determine significant weather based upon the altitude of the weather. The altitude of the weather can be compared to a flight path to determine its significance. A display can provide visual indicia of the significant weather in response to the processing electronics.Type: GrantFiled: September 12, 2006Date of Patent: August 26, 2008Assignee: Rockwell Collins, Inc.Inventor: Daniel L. Woodell
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Patent number: 7414570Abstract: An adaptive broadcast radar system for tracking targets is disclosed. The radar system includes a transmitter having sub-apertures and a receiver having sub-apertures. The transmitter sub-apertures generate and code a signal waveform. The signal waveform is coded with data about the transmitter, including the degrees of freedom. The receiver receives signals that may include direct path signals and scattered signals correlating to the signal waveforms from the transmitter. The receiver includes a signal processor that regenerates a transmit beam for the coded data, delay, and doppler information from the received signals. The signal processor data quads encapsulates the information.Type: GrantFiled: May 23, 2006Date of Patent: August 19, 2008Assignee: Lockheed Martin CorporationInventor: Robert D. Budic
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Publication number: 20080136703Abstract: A transmission side is provided with a power control signal generation section 2 for generating a power control signal whose amplitude is variable in order to equalize a signal intensity of a received signal, and an amplification section 4 for controlling transmission power of a transmission signal of a pulse train, by controlling a gain according to the amplitude of the power control signal.Type: ApplicationFiled: November 30, 2007Publication date: June 12, 2008Applicant: Fuji Jukogyo Kabushiki KaishaInventor: Naohide Yoshimura
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Publication number: 20080122678Abstract: The invention discloses a radar system (100) for the detection of low RCS-objects (110, 140, 150, 160, 190) such as forest fires, said system comprising a first plurality of stations (120) for transmitting radar energy, said stations having mechanically fixed antennas (220), and a second plurality of receive stations (130) for receiving reflections of radar energy transmitted from the transmit stations, said stations having mechanically fixed antennas (220). The antennas (220) of said transmit and receive stations have a main beam (221) which is essentially parallel to the ground, and at least a sub-set of the receive stations is equipped with means for recording a first and a second received signal, and means for subtracting one of said signals from the other of said signals. Said transmit and receive stations are arranged to function within the frequency range of 10-100 MHz.Type: ApplicationFiled: November 30, 2004Publication date: May 29, 2008Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)Inventors: Conrado Rivas, Patrik Rivas, Anders Hook
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Patent number: 7379018Abstract: The method and system provide provisions for generating a respective detection state value associated with each of a plurality of RF receive beams. A first state value is indicative of a detection. The method and system further provide provisions, for each of the detection state values equal to the first state value, for generating a respective detection range value. The method and system further provide provisions for selecting one of the detection state values equal to the first state value and verifying the selected detection state value to provide one of a positive verification and a negative verification associated with the selected detection state value. The method and system further provide provisions for setting the selected detection state value to be equal to the second state value in response to a negative verification.Type: GrantFiled: December 30, 2005Date of Patent: May 27, 2008Assignee: Valeo Raytheon Systems, Inc.Inventors: Stephen P. Lohmeier, Yong Liu
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Patent number: 7379017Abstract: A pulsed radar system uses phase noise compensation to reduce phase noise due to drift of the reference oscillator to enable detection of micro movements and particularly human motion such as walking, breathing or heartbeat. The noise level due to A/D sampling must be sufficiently low for the phase noise compensation to be effective. As this is currently beyond state-of-the-art for high bandwidth A/D converters used in traditional receiver design, the receiver is suitably reconfigured to use analog range gates and narrowband A/D sampling having sufficiently low noise level. As technology continues to improve, the phase compensation techniques may be directly applicable to the high bandwidth A/D samples in traditional receiver designs.Type: GrantFiled: January 24, 2006Date of Patent: May 27, 2008Assignee: Raytheon CompanyInventors: Wesley H. Dwelly, Vinh N. Adams
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Patent number: 7372396Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.Type: GrantFiled: November 10, 2006Date of Patent: May 13, 2008Assignee: Fujitsu Ten LimitedInventor: Masayoshi Shono
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Patent number: 7358887Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. When detecting emitter signals of a particular emitter, the receiver may periodically revisit the portion of the frequency spectrum in which that emitter operates. The revisit time that the receiver uses for a particular emitter may dependent on certain characteristics of the emitter. One of these characteristics is the illumination time of the emitter. Some emitters may present more than one illumination time to a detecting receiver. This may occur, for example, if the emitter sweeps azimuth and changes its elevation angle. Thus, a system and method are provided for computing revisit times for emitters with multi-valued illumination times.Type: GrantFiled: September 30, 2003Date of Patent: April 15, 2008Assignee: Lockheed Martin CorporationInventor: Anthony J. Gounalis
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Patent number: 7342532Abstract: Provided are a radar system and a contamination judging method capable of reducing adjustment costs and detecting contamination adhering to a radome with accuracy. The radar system includes an antenna for transmitting a transmission wave in a plurality of different directions and for receiving a reflected wave, a radome for protecting the antenna, and a signal processing unit for calculating a distance to an object based on the transmission wave and the reflected wave, in which the radome has a metallic reflecting section provided in a predetermined direction with respect to the antenna, the signal processing unit has a contamination judging unit which calculates a deviation between a reception level of the reflected wave from the reflecting section in the predetermined direction and a reception level of the reflected wave from directions other than the predetermined direction and judges contamination adhering to the radome based on the deviation.Type: GrantFiled: March 5, 2007Date of Patent: March 11, 2008Assignee: Mitsubishi Electric CorporationInventor: Katsuji Matsuoka
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Patent number: 7336220Abstract: In order to generate a signal for canceling a chirped signal, a transmitter generates a cancellation signal along with the transmitted signal, using a single term variable complex gain multiplier adapted to cancel the chirped signal only at its instantaneous frequency, rather than attempting to cancel it with a complex FIR filter that works over the entire bandwidth of the chirped signal. The cancellation signal is varied in amplitude and phase as a function of the frequency of the chirped transmit signal for which it is intended to compensate. Since the signal that is to be cancelled is essentially sinusoidal but swept through a frequency range, the cancellation signal for the instantaneous transmit signal needs to be swept in both amplitude and phase in unison with the change in frequency of the transmit signal in order to accommodate gain and phase changes in the transmitted signal as a function of frequency.Type: GrantFiled: June 1, 2006Date of Patent: February 26, 2008Assignee: M/A-Com, Inc.Inventor: Todd Alan Stewart
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Patent number: 7336217Abstract: In a method for interferometric radar measurement, at least two side looking RADAR systems on satellite and/or missile-supported platforms illuminate a common surface area by means of microwave signals. A first side looking RADAR system sends a first radar signal on a first transmit frequency, and at least a second side looking RADAR system sends at least a second radar signal on at least a second transmit frequency. At least one of the at least two side looking RADAR systems receives the at least two interfering radar signals reflected on the common surface area, determines difference phases of the received radar signals from the interferograms, determines therefrom a drift of a system clock of the at least two side looking RADAR systems, and compensates the determined drift.Type: GrantFiled: September 20, 2005Date of Patent: February 26, 2008Assignee: Eads Astrium GmbHInventor: Michael Voelker
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Patent number: 7333051Abstract: A method (for example, machine-implemented, e.g., via a receiver), for determining whether a transmitted pulsed-signal is a linear or non-linear frequency modulated (FM) signal, includes: iteratively determining upper and lower bound slopes associated with frequency components of a pulse of a signal during a time period of the pulse; and comparing each determined upper bound slope to a previous or initial upper bound reference slope and comparing each determined lower bound slope to a previous or initial lower bound reference slope in order to determine the linearity, or non-linearity, of the signal.Type: GrantFiled: November 19, 2004Date of Patent: February 19, 2008Assignee: Lockheed Martin CorporationInventor: Thomas A. Moch
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Patent number: 7327303Abstract: A hybrid radar receiver includes an antenna array for receiving an input signal having a radar signal from a signal emitter. Each array element outputs an analog signal on a respective data channel. For each data channel, an activatable A/D converter is provided. A dedicated hardware circuit, which typically includes a detector/log video amplifier that is coupled to a threshold/pulse digitizer, is included to determine when a radar pulse is being received. When the circuit determines that a pulse is being received, the circuit activates each A/D converter to generate a digital signal on each channel. When a pulse is not currently being received, the circuit deactivates each A/D converter and digital signals are not produced. Pulse parameter(s) generated by the hardware circuit and the digital signals on each channel are sent to a software equipped processor which implements a signal emitter identification algorithm.Type: GrantFiled: March 27, 2007Date of Patent: February 5, 2008Assignee: Information Systems Laboratories, Inc.Inventors: J. Doss Halsey, Katsumi Ohnishi
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Patent number: 7324040Abstract: An attack is activated in a receiver amplifier of an interrogator whenever an amplified input signal exceeds an attack threshold voltage value Vatt, and the receiver amplifier at least during a waiting period, the length of which preferrably equals the double length of the longest time interval between adjacent pulses in a transponder data wave packet, after the end of the attack does not respond in the sense of setting the gain. However, the amplifier responds with a decay activated after the lapse of the waiting period, which started when the instantaneous amplified signal value for the last time after the end of the attack exceeded a waiting threshold voltage level Vw. The decay rate is of the same order of magnitude as the attack rate. The improved method for automatically setting the gain renders it possible that the interrogator receiver within the non-contacting identification system practically does not change the essential characteristics of the input signal.Type: GrantFiled: December 22, 2003Date of Patent: January 29, 2008Inventors: Vinko Kunc, Anton Stern
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Patent number: 7317417Abstract: The present invention relates to active sensor applications, and more particularly is directed to efficient systems and methods for detection and tracking of one or more targets. The invention provides a method for receiving signals reflected from one or more targets, processing the received signals and the transmitted signal to compute two or more slices of the cross ambiguity function associated with the signals, and estimating the signal delay and the Doppler shit associated with the targets from the computed slices.Type: GrantFiled: July 12, 2005Date of Patent: January 8, 2008Inventors: Orhan Arikan, Ahmet Kemal Ozdemir, Donald Spyro Gumas
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Patent number: 7312742Abstract: Sensing characteristics of an object includes transmitting a stepped-frequency radar through an object and detecting, with multiple receiving structures, deflected portions of the radar signal. The detected portions are processed to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected. The processed data is analyzed to determine information corresponding to dielectric properties particular positions within the object.Type: GrantFiled: May 30, 2006Date of Patent: December 25, 2007Assignee: L-3 Communications Security and Detection Systems, Inc.Inventors: William Steinway, David H. Fine, Steve Cole
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Patent number: 7307581Abstract: In a high-frequency circuit having a substrate having a high-frequency transmission line and an dielectric resonator formed on said substrate so that said dielectric resonator and said high-frequency transmission line may be coupled electro-magnetically to each other, a hole part or a cavity part is formed at a part of said substrate and a dielectric resonator is embedded in said hole part or said cavity part. In the same object, a high-frequency circuit having a dielectric resonator is produced by the step for forming a high-frequency transmission line on a substrate, the step for forming a hole part or a cavity part on a part of the substrate, and the step for mounting a dielectric resonator in the hole par formed on the surface of the substrate.Type: GrantFiled: June 21, 2004Date of Patent: December 11, 2007Assignee: Hitachi, Ltd.Inventor: Yoshiyuki Sasada
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Patent number: 7307577Abstract: A method of characterizing a maximum height of a storm cell for an aircraft is provided. First reflectivity data formed from a first scan of a storm cell by a radar is received and a first centroid of the storm cell is identified. Second reflectivity data formed from a second scan of the storm cell by the radar is received and a second centroid of the storm cell is identified. A scan axis for a third scan of the storm cell based on the first centroid and the second centroid is determined. Third reflectivity data formed from the third scan of the storm cell by the radar at a first time is received. The third reflectivity data is sampled to form pixel data that includes a reflectivity indicator determined for each pixel formed from the third reflectivity data. A maximum height of the storm cell is determined by processing the pixel data.Type: GrantFiled: September 28, 2006Date of Patent: December 11, 2007Assignee: Rockwell Collins, Inc.Inventors: Kevin M. Kronfeld, Daniel L. Woodell
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Patent number: 7301495Abstract: A moving radar (405) generates a synthetic aperture image from an incomplete sequence of periodic pulse returns. The incomplete sequence of periodic pulse returns has one or more missing pulses. The radar converts the incomplete sequence of pulse returns into a digital stream. A computer (403) processes the digital stream by computing an along track Fourier transform (402), a range compression (408), an azimuth deskew (410) and an image restoration and auto focus (412). The image restoration and autofocus (412) utilizes a low order autofocus (501), a gap interpolation using a Burg algorithm (503), and a high order autofocus (505) for generating an interpolated sequence. The interpolated sequence contains a complete sequence of periodic pulse returns with uniform spacing for generating the synthetic aperture image. The image restoration and autofocus (412) computes a linear prediction coefficients estimate using the Burg Algorithm (606).Type: GrantFiled: January 11, 2006Date of Patent: November 27, 2007Assignee: Raytheon CompanyInventors: Theagenis John Abatzoglou, Leo H. Hui, Kwang M. Cho
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Patent number: 7298315Abstract: A radar pulse compression repair (RPCR) system includes a receiver for receiving a radar return signal, a matched filter for applying matched filtering to the radar return signal to generate a matched filter output, a processor programmed for applying Radar Pulse Compression Repair (RPCR) to the matched filter output to suppress a plurality of range sidelobes from the matched filter output, and a detector for receiving the RPCR-processed output. The RPCR invention in operating upon the output of the matched filter enables RPCR to be employed as a post-processing stage in systems where it is not feasible to replace the existing pulse compression apparatus. RCPR can also be selectively employed when it is possible that large targets are present that may be masking smaller targets, thereby keeping computational complexity to a minimum.Type: GrantFiled: November 7, 2005Date of Patent: November 20, 2007Assignee: The United States of America as represented by the Secretary of the NavyInventors: Karl R Gerlach, Shannon D Blunt
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Patent number: 7295148Abstract: There is provided a radar system having an input amplitude correcting function in which even when a large reflection wave exceeding a dynamic range of an A/D converter is inputted, an RCS calculation without a time lag can be executed at high precision, high reliability, and low costs without using power amplification degree control such as an AGC circuit or the like. Harmonic peaks of each target peak of an FFT-processed frequency spectrum are detected. When the harmonics are detected, it is determined that the large reflection wave exceeding the dynamic range of the A/D converter has been inputted, and a lost input amplitude is corrected in accordance with a correction table showing a relation between the harmonic order and an input amplitude correction amount which have previously been recorded.Type: GrantFiled: October 28, 2004Date of Patent: November 13, 2007Assignee: Hitachi, Ltd.Inventor: Ryuji Fukute
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Patent number: 7289060Abstract: A radar classifies an unknown target illuminated with a large bandwidth pulse. The large bandwidth pulse may be algorithmically synthesized. The target reflects the large bandwidth pulse to form a return. The return is digitized into digital samples at range bin intervals. A computer extracts unknown range and amplitude pairs descriptive of the unknown target from the digital samples. Some range and amplitude pairs are located within one range bin interval. Principle scatterers are extracted from the unknown range and amplitude pairs using Modified Forward backward linear Prediction to form an unknown feature vector for the target. A plurality of pre-stored, known feature vectors containing known range and amplitude pairs are retrieved from the computer. The known range and amplitude pairs are descriptive of known targets, and are grouped in clusters having least dispersion for each of the known targets.Type: GrantFiled: May 24, 2006Date of Patent: October 30, 2007Assignee: Raytheon CompanyInventors: Theagenis J. Abatzoglou, Raquel E. Maderazo, Jessica E. Swanson, Frederick A. Dominski
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Patent number: 7286080Abstract: Provided is a millimeter-wave transmitting/receiving apparatus of pulse-modulation type in which pulse-modulated millimeter-wave signals for transmission are prevented from being outputted to a reception system due to inner reflection or other causes. Included are: an NRD guide (basic structure) formed of a dielectric line sandwiched between parallel plate conductors; a millimeter-wave signal oscillator; a pulse modulator; a circulator; a transmitting/receiving antenna; and a mixer. At the output end of the mixer is disposed a switching device which interrupts intermediate-frequency signals in an opened state, and, when a millimeter-wave signal for transmission from the pulse modulator enters a non-output state and the condition is stabilized, changes into a closed state to pass intermediate-frequency signals.Type: GrantFiled: August 27, 2004Date of Patent: October 23, 2007Assignee: Kyocera CorporationInventors: Yoshihiro Sakamoto, Yuji Kishida, Kazuki Hayata, Yoshiko Oya
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Patent number: 7274324Abstract: A path in three-dimensions for an object in flight is determined according to a radar signal reflected by the object. The radar signal is transmitted at an offset angle from horizontal sufficient to capture the object within the transmitted radar signal. The transmitted radar signal is reflected by the object to form a reflected radar signal containing an indication of a position of the object. The reflected radar signal is received and used to determine two-dimensional position information for the object by detection of the indication of the position of the object in the received radar signal. Position information is derived in three-dimensions from the position information in two-dimensions. The path information representative of the path for the object is obtained from the position information in three-dimensions based on an optimization of a curvature of said path information.Type: GrantFiled: July 8, 2002Date of Patent: September 25, 2007Assignee: Her Majesty the Queen in Right of Canada as Represented by the Minister of National DefenseInventors: Rhonda L. Millikin, Joseph R. Buckley
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Patent number: 7259714Abstract: A method of detecting radar returns and measuring their parameters with or without clutter present and no clutter cancellation employed which includes transmitting at least one pulse; processing the returns surpassing a threshold detected in one range azimuth bin and by processing and separating out the returns based on their different range and azimuth. Another method includes transmission of many pulses and has minimum of one channel return surpassing detected threshold, which is detected in one range Doppler bin. The method also includes processing and thereby separating out the returns based on their different radial velocity and or azimuth and comparing the returns to a database of expected returns and adaptively processing returns that do not correspond to the expected returns. The method identifies the non-corresponding returns as indicative of at least one of clutter, land sea interface, clutter discretes and antenna sidelobe returns each without utilizing clutter cancellation.Type: GrantFiled: May 1, 2006Date of Patent: August 21, 2007Inventor: Thomas J. Cataldo
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Patent number: 7248210Abstract: The present invention is a man-portable counter-mortar radar (MCMR) radar system that detects and tracks enemy mortar projectiles in flight and calculates their point of origin (launch point) to enable and direct countermeasures against the mortar and its personnel. In addition, MCMR may also perform air defense surveillance by detecting and tracking aircraft, helicopters, and ground vehicles. MCMR is a man-portable radar system that can be disassembled for transport, then quickly assembled in the field, and provides 360-degree coverage against an enemy mortar attack.Type: GrantFiled: March 15, 2005Date of Patent: July 24, 2007Assignee: Syracuse Research CorporationInventors: Steven E. Bruce, Thomas A. Wilson
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Patent number: 7236125Abstract: A method for reducing angular blur in radar pictures achieved in range bin based detection systems includes measuring a variable S(x, y) such as amplitude or power as a function of an angle x and a distance y. An expression: corrected angular position=angular position+angle correction is determined in each range bin for a plurality of angular values x. The term “angle correction” includes derivative(s) of first or higher order of the variable S(x). The variable measured at the angular position “angular position” is moved to the variable in the angular position “corrected angular position”, and the moved variable and the variable in “corrected angular position” are processed by adding or maximizing the values.Type: GrantFiled: January 25, 2005Date of Patent: June 26, 2007Assignee: SAAB ABInventor: Bert-Eric Tullsson
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Patent number: 7218274Abstract: 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: GrantFiled: October 21, 2003Date of Patent: May 15, 2007Inventors: Orhan Arikan, Ahmet Kemal Ozdemir
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Patent number: 7215276Abstract: A method for detecting radar is provided by the present invention. The invention begins by sweeping a first local oscillator (LO). Once a band has been identified as containing a radar signal, the detector interrupts its normal operation and rechecks the frequency in question for confirmation of CW radar, rather than waiting for the initial sweep to finish. Upon receiving partial information from the initial fast sweep, the detector may repeat this sweep at a slower rate in order to improve sensitivity towards a CW source. If information was from a CW source one can be assured to see the information again when sweeping the same frequency. By contrast, if initial information is from a swept radar detector the information will not be present in the rescan, as the offending radar detector would have moved to a different frequency during the same period of time.Type: GrantFiled: December 19, 2003Date of Patent: May 8, 2007Assignee: The Whistler Group, Inc.Inventors: Michael Batten, Craig R. Autio
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Patent number: 7209072Abstract: A method of radar measurement by transmitting and receiving radar signals with at least two spatially separated radar systems. The method further includes exchanging reference radar signals between the at least two radar systems to determine measurement-relevant parameters. Moreover, a determination of at least one of a relative phase relationship of the reference radar signals of the radar systems and a relative time position of time references of the radar systems is based on reference radar signals received. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.Type: GrantFiled: October 14, 2004Date of Patent: April 24, 2007Assignee: EADS Astrium GmbHInventors: Harald Braubach, Michael Voelker
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Patent number: 7205932Abstract: An improved system is provided for aiming a shotgun-based or other countermeasure system so as to be able to countermeasure incoming rockets or projectiles. In one embodiment a shotgun aimed and controlled by the subject system projects a pattern of pellets to intercept a rocket-propelled grenade or incoming projectile. The fire control system uses a CW two-tone monopulse radar to derive range and angle of arrival within 150 milliseconds, with range and angle of arrival measurements having approximately twice the accuracy of prior CW two-tone monopulse radars. The improvement derives from using all of the information in the returned radar beams and is the result of the recognition that one can use the Sum and Difference signals to assemble a two-by-two Rank One matrix that permits using singular value decomposition techniques to generate range and angle of arrival matrices in which all available information is used and in which noise is eliminated.Type: GrantFiled: October 1, 2004Date of Patent: April 17, 2007Assignee: BAE Systems Information and Electronic Systems Integration Inc.Inventor: Paul D. Fiore
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Patent number: 7205929Abstract: An electromagnetic wave is transmitted from a signal transmission antenna using a signal transmission IC; this electromagnetic wave is received, after having been reflected by a target object, by signal receiving antennas and signal receiving ICs; and the distance to the target object or the azimuth of the target object is detected by a signal processing section. The signal receiving antennas have approximately the same signal receiving characteristics and directivity in approximately the same direction, and are arranged in a row with a predetermined gap between them, thus constituting an antenna array.Type: GrantFiled: June 25, 2005Date of Patent: April 17, 2007Assignee: Honda Motor Co., Ltd.Inventors: Masahito Shingyoji, Hiroyuki Ando
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Patent number: 7199751Abstract: A radar equipment of the present invention amplifies a reception signal with feedback based on the delay amount obtained from the correlation detection result. Accordingly, it becomes possible to maintain the reception signal (demodulated signal) level to a proper level depending on the distance to the target, and accurate measurement can be achieved with high precision. Namely, the reception signal is amplified depending on the distance to the target, and the reception signal level is made within a tolerable input level range of a logic circuit for performing correlation calculation. In particular, during tracking the target, even when a reflected signal is received with abrupt level variation caused by noise or a reflected signal from an object other than the target, incorrect detection of the target can be avoided by disabling the correlation calculation.Type: GrantFiled: November 8, 2004Date of Patent: April 3, 2007Assignee: Fujitsu LimitedInventors: Satoshi Mikami, Kaoru Yokoo, Takayuki Sasaki, Takahiro Suzuki
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Patent number: 7196656Abstract: An apparatus for estimating direction of arrival of signal is provided that has excellent performance in terms of angular resolution and the number of signals that can be identified. In an array sensor comprising a plurality of sensor elements, the two outermost sensor elements are alternately selected by a switch for use as a transmitting sensor, and the other sensor elements are selected in time division fashion as receiving sensors. With this arrangement, the effective aperture is increased to about twice the physical aperture, to improve angular resolution in a direction-of-arrival estimator.Type: GrantFiled: December 21, 2004Date of Patent: March 27, 2007Assignee: Fujitsu LimitedInventor: Kazuo Shirakawa
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Patent number: 7193557Abstract: Tracking objects by receiving a dataframe from a detection sensor device, the dataframe containing a timestamp and data corresponding to each detected object, generating new observation nodes for each detected object, propagating group track state parameters to obtain posterior observable positions and projecting them onto the received dataframe, generating gates for the posterior observable positions and projecting them onto the received dataframe, determining feasible track node and feasible observation node assignments based on the proximity of the new observation nodes to the gates, updating track node state parameters and corresponding scores, performing a multi-frame resolution algorithm to resolve group track nodes into subtrack nodes, determining a set of feasible composite assignments for composite sets of track nodes and observation nodes, updating track node state parameters and corresponding scores, and determining a selected set of joint assignments based on the feasible composite assignments andType: GrantFiled: April 29, 2004Date of Patent: March 20, 2007Assignee: Lockheed Martin CorporationInventors: Michael A Kovacich, Thomas R Casaletto
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Patent number: 7193555Abstract: A method for receiving at least one signal emitted by at least one emitter includes defining a first dwell associated with a first signal. The first dwell has a frequency range that overlaps at least a portion of a frequency range of a second signal. The method also includes detecting the second signal responsive to the first dwell if the first dwell satisfies at least one criterion for detecting the second signal. The method further includes rejecting the second signal responsive to a characteristic of the second signal if the first dwell fails to satisfy the at least one criterion.Type: GrantFiled: March 31, 2005Date of Patent: March 20, 2007Assignee: Lockheed Martin CorporationInventor: Anthony J. Gounalis
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Patent number: 7187321Abstract: Occurrence of interference is detected using sampled amplitude data obtained by oversampling a beat signal. It is detected by comparing the absolute value (|VD|) of variation in the sampled data with a threshold value (TH). When interference occurs, a wideband signal is superposed on the beat signal, and this disturbs the signal waveform of the beat signal to drastically varies its amplitude. Therefore, occurrence of interference can be detected without fail regardless of the scheme on which a radar as the source of an interference wave is based and even when the amplitude of the interference wave is low. In addition, when low-frequency noise is superposed on the beat signal, erroneous detection of occurrence of interference can be prevented.Type: GrantFiled: April 13, 2006Date of Patent: March 6, 2007Assignee: Denso CorporationInventors: Yuu Watanabe, Kazuma Natsume
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Patent number: 7187320Abstract: A target tracking arrangement predicts the state of a target. The predictor may be a Kalman filter. In the presence of a target which is maneuvering, the prediction may be in error. A maneuver detector is coupled to receive residuals representing the difference between the predictions and the target state. The maneuver detector is matched to the predictor or Kalman filter to thereby tend to reduce the undesirable effects of system noise. The matching may be of the frequency response.Type: GrantFiled: August 27, 2004Date of Patent: March 6, 2007Assignee: Lockheed Martin CorporationInventor: Robert E. Yang
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Patent number: 7180442Abstract: A method of identifying an unknown target comprising creating a density function of cepstral coefficients for a known target; receiving a signal from the unknown target; transforming the signal from a time spectrum to a frequency spectrum using a Fourier transform; transforming the frequency spectrum to a cepstrum; creating a density function of cepstral coefficients for the unknown target; and comparing the density function of the unknown target with the density function of the known target.Type: GrantFiled: May 3, 2006Date of Patent: February 20, 2007Assignee: The United States of America as represented by the Secretary of the NavyInventor: Thach N. Nguyen
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Patent number: 7176826Abstract: A system and method is provided for detecting emitter signals and for determining a scan strategy for a receiver system that receives such emitter signals. A rule-based system is provided for determining how emitters should be detected by a detection system. Rules may be used to prioritize certain emitters with respect to other emitters. The rules may also specify parameters for emitter modes, such as probability of intercept, turn-on range, detect-by range, tolerance, tolerance direction, scan periods, and other parameters. The rules may be used to compute the revisit time for the receiver. Multiple sets of rules may be created and a scan strategy may be computed based upon the selected rule set.Type: GrantFiled: December 28, 2005Date of Patent: February 13, 2007Assignee: Lockheed Martin CorporationInventor: Anthony J. Gounalis
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Patent number: 7167124Abstract: A system and method for measuring ground penetrating radar data is described which includes controlling the timing for generating stimulus electromagnetic waves and the sampling rate of reflected electromagnetic waves in response to the stimulus electromagnetic waves. Generally, the timing is adjusted for spatially over-sampling the ground penetrating radar data. The speed of the system can also be adjusted based on the measured data.Type: GrantFiled: December 22, 2005Date of Patent: January 23, 2007Assignee: Sensors & Software Inc.Inventors: Alexander Peter Annan, Steve Cosway
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Patent number: 7161528Abstract: The invention relates to a method of suppressing pulsed signals in particular of DME or TACAN type present in the radio signals received (Ue) by a radio-frequency receiver, characterized in that the reception frequency band of the receiver is divided into frequency sub-bands corresponding to the transmission channels of the pulsed signals, in that the presence of the pulsed signals and the transmission channel of said pulsed signals in the frequency sub-bands are detected, and in that the frequency sub-band comprising the detected pulsed signals is filtered over the duration of the pulsed signal so as to eliminate said pulsed signals pulse type.Type: GrantFiled: December 20, 2002Date of Patent: January 9, 2007Assignee: ThalesInventors: Estelle Kirby, Alain Renard
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Patent number: 7161529Abstract: Analysis of electromagnetic (or acoustic) multipath propagation inventively focuses upon the transmitter-to-target propagation (transmitted propagation reaching target via both direct pathway and forward scattered pathway) and the target-to-receiver propagation (re-transmitted propagation reaching receiver via both direct pathway and forward scattered pathway). Transmitter-to-target propagation is calculated using conventional multipath modeling technique. The target's overall scattered field is calculated using the calculated transmitter-to-target propagation in conjunction with qualitative electromagnetic/acoustic target information. Target-to-receiver propagation is calculated using conventional multipath modeling technique and/or the reciprocity principle as applied to the calculated transmitter-to-target propagation.Type: GrantFiled: May 27, 2004Date of Patent: January 9, 2007Assignee: The United States of America as represented by the Secretary of the NavyInventor: Jerry Rosson Smith, Jr.
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Patent number: 7154431Abstract: A digital synthesizer includes a digital radio frequency memory (DRFM) for storing phase values and corresponding digital signals. The digital synthesizer includes a digital processing circuit receiving input from the DRFM, the circuit including tapped delay lines and a summer summing the output of the tapped delay lines. The digital synthesizer includes a signal modulator independently synthesizing within each tapped delay line a frequency modulated and gain scaled signal, wherein input to the tapped delay lines are phase values from the DRFM.Type: GrantFiled: March 1, 2004Date of Patent: December 26, 2006Assignee: The United States of America as represented by the Secretary of the NavyInventors: Phillip E. Pace, Robert E. Surratt, Siew-Yam Yeo
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Patent number: 7151484Abstract: A pulse compression processor 20 compressing a modulated pulse signal correlately received by a receiver, includes a coefficient calculator 30 calculating a set of filtering coefficients for converting sampled output signal values outside a vicinity of main-lobe of a compressed pulse signal into zero as well as for minimizing S/N loss in a peak value of the main-lobe, and a pulse compression filter 40 compressing the modulated pulse signal based on the set of the filtering coefficients calculated by the coefficient calculator.Type: GrantFiled: September 29, 2004Date of Patent: December 19, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Mitsuyoshi Shinonaga, Shinkichi Nishimoto
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Patent number: 7148835Abstract: A method and apparatus for evaluating whether one or more threat sources is actively tracking an object, such as an aircraft. A tracking system may analyze information regarding signals received from a source and provide a track indication that the source is actively tracking the object without adjusting the dwell arrangement of the scan strategy of the receiver. A track indication may be provided where a sample count of signal intercepts from the source is greater than a track count during a window. A break track indication representing that the source is not actively tracking the object may be provided when a number of signal intercepts from the source is less than a break track count during a window.Type: GrantFiled: June 24, 2005Date of Patent: December 12, 2006Assignee: Lockheed Martin CorporationInventors: Jeffrey K. Bricker, Anthony J. Gounalis, James C. Rosswog, Stephen P. Wanchissen
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Patent number: 7145503Abstract: A surface wave radar system including a receive antenna array (20, 22) for generating receive signals, and a data processing system (24) for processing received data representing the receive signals to mitigate ionospheric clutter. The received data is range and Doppler processed, and a spatial adaptive filter (52) is trained using training data selected from the processed data. The training data includes ionospheric clutter data and excludes cells which contain target data and substantial sea clutter. The processed data is filtered using the filter (52), which may be based on loaded sample matrix inversion. The antenna array (20,22) may be two-dimensional having an L or T shape.Type: GrantFiled: November 12, 2002Date of Patent: December 5, 2006Assignee: Telstra Corporation LimitedInventors: Yuri Abramovich, Pavel Turcaj, Nicholas Keith Spencer, Robert M Ellard, Yuriy Lyudviga
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Patent number: 7145500Abstract: A pulse wave radar device controls an amplification degree of a receiving circuit, downward at a time of measuring an object at a short distance immediately after transmission of a transmitting pulse wave and upward, at a time of measuring the object at a long distance, by increasing the amplification degree of the receiving circuit progressively with the lapse of time after the transmission of the transmitting pulse wave.Type: GrantFiled: August 30, 2005Date of Patent: December 5, 2006Assignee: TDK CorporationInventors: Hiroshi Ikeda, Hideaki Shimoda, Takeshi Yokoyama
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Patent number: 7142150Abstract: A method and system for detecting an object uses a composite evidence grid based on dual frequency sensing. A source transmits a laser transmission in a first zone. A detector receives a reflection of the laser transmission from an object in the first zone to determine laser observed data associated with points on the object. A transmitter transmits a radar transmission in a second zone that overlaps with the first zone. A receiver receives a reflection of the radar transmission from an object in the second zone to determine radar observed data associated with points on the object. The laser observed data is processed to form a laser occupancy grid for the first zone and the radar observed data is processed to form a radar occupancy grid for the second zone. An evaluator evaluates the radar occupancy grid and the laser occupancy grid to produce a composite evidence grid for at least an overlapping region defined by the first zone and the second zone.Type: GrantFiled: December 15, 2004Date of Patent: November 28, 2006Assignee: Deere & CompanyInventor: Robert George Thackray
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Patent number: 7142153Abstract: A unique hardware architecture that combines short pulse, stepped frequency and centerline processing. The inventive architecture implements a radar system having a transmitter for transmitting short pulses, each pulse being stepped in frequency and a receiver receiving the pulses and providing an output signal in response thereto. In the illustrative embodiment, the transmitter includes a frequency source, an RF switch coupled to the source and a controller for controlling the RF switch. The receiver includes a signal processor implemented with a center line roughing filter. The signal processor has multiple channels each of which has a range gate and a digital filter. The digital filter includes a Fast Fourier Transform adapted to output a range Doppler matrix.Type: GrantFiled: June 8, 2004Date of Patent: November 28, 2006Assignee: Raytheon CompanyInventors: Wesley H. Dwelly, Vinh N. Adams