With Plural Fixed Range Gates Patents (Class 342/136)
  • Patent number: 11187800
    Abstract: A weather radar module includes a memory, a vertical weather display, and a processor. The vertical weather display is configured to display weather in a vertical format. The processor is configured to control a radar antenna of the aircraft to perform a sweep in the horizontal direction and receive horizontal sweep radar returns, determine first weather parameters of a weather model in the vertical format based on the horizontal sweep radar returns, and store the first weather parameters in the memory. The processor is further configured to provide an estimate of the weather in the vertical format based on fusing vertical weather data, which is based on the vertical sweep radar returns, with the first weather parameters in the memory or with vertical display data based on the first weather parameters, and cause the vertical weather display to display the estimate of the weather in the vertical format.
    Type: Grant
    Filed: September 2, 2015
    Date of Patent: November 30, 2021
    Assignee: Rockwell Collins, Inc.
    Inventors: Mark C. Fersdahl, Nathanael A. Meyer, Luis R. Granadillo, Edward A. St. John, Derek G. White
  • Patent number: 9494682
    Abstract: Disclosed is a radar weather data signal processing module comprising: a pulse compression unit for pulse-compressing a received weather signal; a correlation coefficient calculation unit for calculating a correlation coefficient on the basis of the pulse-compressed weather signal; and a weather variable calculation unit for calculating a weather variable on the basis of the calculated correlation coefficient.
    Type: Grant
    Filed: April 8, 2014
    Date of Patent: November 15, 2016
    Assignee: WEATHERLINK CO., LTD
    Inventor: Jeongho Choi
  • Patent number: 8724677
    Abstract: Provided are a method and apparatus (receiver) of receiving and processing a radio signal in a transmitter-receiver environment. The radio signals are transmitted across a wireless interface using Ultra Wideband (UWB) pulses. A transmitted reference approach is utilized. The radio signal include pairs of UWB pulses with each pair of pulses separated by a fixed time delay. The two pulses are then combined to provide for improved noise immunity.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: May 13, 2014
    Assignee: University of South Florida
    Inventor: James L. Tucker
  • Patent number: 8588270
    Abstract: The invention includes a method for transmitting and detecting high speed Ultra Wideband pulses across a wireless interface. The transmitter includes a serializer and pulse generator. The receiver comprises a fixed delay line, multiplier, local serializer (with a sequence matching the transmitter), digital delay lines, low noise amplifier and logic fan-out buffer along with an array of D flip-flop pairs. Each flip-flop pair is enabled, at fixed time increments, to detect signals at a precise time; the timing is controlled by the pseudo-random sequence generated by the local serializer. A local tunable oscillator is controlled by detecting the phase change of the incoming signal and applying compensation to maintain the phase alignment and clock synchronization of the receiver to the clock reference of the transmitter. The invention uses a pair of pulses with a fixed delay and then relies on mixing the two to provide better noise immunity.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: November 19, 2013
    Assignee: University of South Florida
    Inventor: James L. Tucker
  • Patent number: 8432309
    Abstract: A radar system (44) for a vehicle (42) includes a transmit unit (56) and a receive unit (58). The transmit unit (56) includes a single beam antenna (72) for output of a radar signal (74) into a target zone (46). The receive unit (58) includes a single beam antenna (76) for receiving a direct receive signal (78) and an indirect receive signal (80). The receive signals (78, 80) are reflections of the radar signal (74) from an object (34, 36) in the target zone (46). The indirect receive signal (80) is reflected off the object (34, 36) toward a reflective panel (54) of the vehicle (42), and the indirect receive signal (80) is reflected off the reflective panel (54) for receipt at the receive antenna (76). The receive signals (78, 80) are summed to produce a detection signal (81) indicating presence of the object (34, 36) in the target zone (46).
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: April 30, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: James D. MacDonald, Lawrence A. Rubin
  • Patent number: 8421669
    Abstract: A synthetic aperture processing system that includes a signal transmission unit for generating and radiating a plurality of chirp waves to an irradiation region from measuring sites, a signal reception unit for receiving a plurality of reflected waves caused by the plurality of chirp waves, a range compression unit for range-compressing each of the reflected waves and generating reception data consisting of sinc functions, a cross-correlation computation unit for, based on a plurality of model data segments, calculating correlation values representing a degree of correlation between each of the model data segments and the reception data, and image output unit for outputting the correlation values calculated by cross-correlation computation unit.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: April 16, 2013
    Assignee: Japan Agency for Marine-Earth Science and Technology
    Inventor: Takao Sawa
  • Patent number: 8264401
    Abstract: A micro-radar is disclosed that is operated based upon two Digital to Analog Converter (DAC) outputs that control its internal timing and Intermediate Frequency (IF) signal frequency. Calibration and temperature compensation is done through estimating the duty cycle of the transmit signal and possibly the reception signal that stimulate a pulse generator to create the transmit pulse and the reception pulse and adjusting one or both DAC outputs. Sensor processors, wireless sensor nodes and wireline sensor nodes are disclosed for operating the micro-radar. An integrated circuit is disclosed implementing all or portions of the micro-radar. Access points, servers as well as systems that include but are not limited to a traffic monitoring system, a traffic control system, a parking management system and/or a production management system are also disclosed.
    Type: Grant
    Filed: April 22, 2012
    Date of Patent: September 11, 2012
    Assignee: Sensys Networks, Inc.
    Inventor: Robert Kavaler
  • Patent number: 8193974
    Abstract: Signal compensation systems and methods compensate an estimated range profile from a plurality of detected signal returns from a true range profile, wherein the signal returns correspond to an emitted stepped frequency pulse-train. An exemplary embodiment utilizes knowledge of the radar system design to identify locations, predict power levels, and suppress the contributions of stepped-frequency range sidelobes (ambiguous peaks) in the estimated range profile, resulting in a cleaner and more accurate radar display.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: June 5, 2012
    Assignee: Honeywell International Inc.
    Inventors: Gloria Logan, Brennan Kilty, Paul Christianson
  • Patent number: 7889118
    Abstract: A radar system includes an antenna and has short range detection capability. The radar system includes a receiver coupled to the antenna for receiving a receive signal associated with a pulse compressed transmission signal and a matched filter configured to accumulate at least a portion of the receive signal for a particular range. The portion of the receive signal is associated with a corresponding portion of the pulse compressed transmission signal.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: February 15, 2011
    Assignee: Rockwell Collins, Inc.
    Inventors: Jeffery A. Finley, Daniel L. Woodell
  • Patent number: 7880668
    Abstract: According to an embodiment of the disclosure, a computer implemented method of configuring a land-based radar system for scanning a scan region is disclosed. The method comprises dividing the scan region into a grid of blocks and obtaining a terrain elevation data for the scan region. For an elevation angle for the radar system, determining those blocks in the grid that are visible to the radar system and those blocks that are not visible to the radar based on the terrain elevation data. Then, step of determining the visible blocks is repeated for all elevation angles in a predefined set of elevation angles for the radar system. Next, an optimal scan elevation angle for the radar system is determined as the scan elevation angle which resulted in the maximum number of visible blocks in the scan region and the radar system is set to the optimal scan elevation angle.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: February 1, 2011
    Assignee: Lockheed Martin Corproation
    Inventors: Stefan M. Krause, Eric D. Toal, Louis Lagonik
  • Publication number: 20100265122
    Abstract: A radar system comprising a transmitter to transmit radar signals into a region, a receiver to receive return signals of said radar signals reflected from within the region wherein the transmitter and receiver are adapted for location on a structure at a wind farm, and a processor to process the return signals to extract wind farm associated data for said region.
    Type: Application
    Filed: May 29, 2008
    Publication date: October 21, 2010
    Inventor: Gordon Kenneth Andrew Oswald
  • Patent number: 7463181
    Abstract: In a method for suppressing interferences while detecting objects in a target area, a transmitter transmits a sequence of pulses into the target area, and a receiver detects the resulting reflection signal of the pulses reflected from the objects, within successive time windows that are referenced to the moment of transmitting an individual pulse and thus represent distance gates. The time spacing between the successive individual pulses is variable and randomized according to the pseudo-noise principle within predetermined limits, and the time windows are adapted accordingly. The received reflection signal may be sampled, digitized, digitally pre-processed and digitally filtered in the individual distance gates. A non-linear digital filter, preferably a sliding median filter, is used for the filtering to suppress transient disturbances. The median is determined from an odd number of consecutive sampled values of a reflection signal detected within a distance gate.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: December 9, 2008
    Assignee: A.D.C. Automotive Distance Control Systems GmbH
    Inventor: Markus Wintermantel
  • Patent number: 7259713
    Abstract: A continuous wave ranging system, comprising a modulator 2 for modulating an r.f. carrier wave in accordance with a pseudo random code, a transmitting antenna 5 for radiating the modulated signal towards a target, a receiving antenna 6 and receiver 7 for detecting the signal reflected back from the target, a correlator 8 for correlating the reflected signal with the transmitted code with a selected phase shift corresponding to the current range gate to be tested, whereby the range of the target from the system may be determined, a store 12 containing a plurality of different pseudo random codes, and selector means 13 arranged to supply to the modulator 2 and to the correlator 8 a code from the store 12 which code does not produce a breakthrough sidelobe in at least the next range gate or gates to be tested.
    Type: Grant
    Filed: August 16, 1990
    Date of Patent: August 21, 2007
    Assignee: Selex Sensors and Airborne Systems Limited
    Inventors: George Edward Matich, David Henry Ramsey, Raymond John Walls
  • Patent number: 7012561
    Abstract: In order to refine a device and a method for registering, detecting, and/or analyzing at least one object, a registration range and/or at a detection gate being displaced at a scanning speed over a measuring range, in such a way that a target-unique velocity measurement is ensured in continuous detection operation with low latency time and resistance to fluctuations, it is provided that, the receive circuit be divided into at least two channels, which are operable separately from one another, in particular using at least one power divider unit connected downstream from the output terminal of the I/Q mixing unit, of which the first channel of the receive circuit is designed for the purpose of displacing the registration range and/or the detection gate at a constant scanning speed over the entire measuring range, and the second channel of the receive circuit is designed for the purpose of displacing the registration range and/or the detection gate at a variable, in particular reducible scanning speed over the m
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: March 14, 2006
    Assignee: Robert Bosch GmbH
    Inventors: Tore Toennesen, Martin Reiche
  • Publication number: 20040263382
    Abstract: A pulse radar system has a high-frequency source, which supplies a continuous high-frequency signal and is connected on the one side to a transmission-side pulse modulator and on the other side to at least one mixer in at least one receive path. A pulse modulator is connected upstream of the mixer with regard to its connection to a receiving antenna. The mixer evaluates a radar pulse reflected by an object together with the signal of the high-frequency source. This system does not require a ZO switch and is insensitive to interference.
    Type: Application
    Filed: August 6, 2004
    Publication date: December 30, 2004
    Inventor: Frank Gottwald
  • Patent number: 6822605
    Abstract: A radar device is described having means (12) for generating a first code, means (18) for modulating a transmission signal in a transmitting branch using the first code, means (32) for delaying the first code, means (20) for modulating a signal in a receiving branch using the delayed first code, and means for mixing a reference signal with a reception signal, multiple receiving channels (111, 112, . . . 11k) being provided, the receiving channels (111, 112, . . . 11k) having means (1201, 1202, . . . 120k) for generating additional codes (C1, C2, . . . Ck), the receiving channels (111, 112, . . . 11k) having means (131, 132, . . . 13k) for demodulating using the respective additional codes (C1, C2, . . . Ck), and means (15) being provided for modulating the transmission signal using at least one of the additional codes (C1, C2, . . . Ck). A method which may be implemented advantageously using the radar device described is also described.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: November 23, 2004
    Assignee: Robert Bosch GmbH
    Inventor: Thomas Brosche
  • Patent number: 6750804
    Abstract: A system and method for detecting a target. The inventive method includes the steps of receiving a complex return signal of an electromagnetic pulse having a real and an imaginary component; extracting from the imaginary component information representative of the phase component of the return signal; and utilizing the phase component to detect the target. Specifically, the phase components are those found from the complex range-Doppler map. More specific embodiments further include the steps of determining a power spectral density of the phase component of the return signal; performing a cross-correlation of power spectral density of the phase component of the return signal between different antenna-subarray (quadrant channels); and averaging the cross-correlated power spectral density of the low frequency components. In an alternative embodiment, the cross-correlation is performed on the phase component of the range-Doppler map directly.
    Type: Grant
    Filed: April 4, 2002
    Date of Patent: June 15, 2004
    Assignee: Raytheon Company
    Inventors: Hai-Wai Chen, Harry A. Schmitt, George T. David, Dennis C. Braunreiter, Alphonso A. Samuel
  • Publication number: 20040070532
    Abstract: An embodiment comprises a unit generating a control pulse signal by delaying a basic signal in generating a transmission pulse, and a unit performing a gate operation on a received signal using the control pulse signal. Another embodiment comprises a unit generating a control pulse signal by delaying a signal generated using a first basic signal, a second signal for phase modulation having a lower frequency than the first signal, and a pseudo-random signal generated at an intermediate frequency between the frequencies of the first and second signals, and a unit performing the gate operation.
    Type: Application
    Filed: October 8, 2003
    Publication date: April 15, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Satoshi Ishii, Yoshikazu Dooi, Hiroyuki Yatsuka, Tetsuo Seki, Kazuaki Hamada
  • Publication number: 20030210176
    Abstract: A method for resolving radar range ambiguities is disclosed, where the radar is modulated with a phase code which comprises a number of chips. The method includes acquiring a radar return within a verify gate, the verify gate being aligned with one chip of the phase code, determining an amplitude of the return, stepping the gate outbound to a next chip of the code, acquiring a return, and determining if the return has an amplitude greater than a threshold based on the original return. The verify gate is repeatedly stepped outbound to determine if a chip can be found which has an amplitude in excess of the threshold or until returns from all chips within the phase code have been acquired. If such a position is found, search logic of the radar is moved outbound to the chip position which had the highest amplitude return, if not the original chip position and the entire process begins again.
    Type: Application
    Filed: May 13, 2002
    Publication date: November 13, 2003
    Inventors: James R. Hager, Todd R. Burlet, Jens M. Henrickson
  • Patent number: 6590522
    Abstract: A pulse radar device, which includes a timing control unit that controls a transmit interval of a pulse signal, a transmitting unit that transmits the pulse signal, a receiving unit that receives a receive signal including a reflection signal component from a target object and a noise component, a receive signal change detecting unit that detects a change in the assembly of the receive signals of the assembly of the pulse signals which are transmitted during a first transmit interval and the assembly of the pulse signals which are transmitted during a second transmit interval, a reflection signal rising detecting unit that detects a rising time point of the reflection signal component, and a ranging/detecting unit that obtains a distance value on the basis of the rising time point of the reflection signal and judges the presence of the target object.
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: July 8, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shigekazu Okamura
  • Patent number: 6480142
    Abstract: A method and apparatus for measuring the parameters of atmospheric turbulent flows utilizes the Doppler shifted frequencies of received radar signals backscattered from sound generated aerodynamically by atmospheric turbulent flows. Doppler frequency bandwidths of the received backscattered signals are used to estimate the atmospheric flow turbulence and the mean frequency within a bandwidth is processed to estimate its radial flow velocity. Total flow velocity and the flow velocity angle with respect to the antenna boresight of the atmospheric turbulent flow may be estimated by estimating the radial flow velocity at two radial positions and processing these radial velocities. Processing of the Doppler data is initiated when the total signal power within the Doppler frequency band exceeds a predetermined power level.
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: November 12, 2002
    Inventor: William L. Rubin
  • Publication number: 20020163465
    Abstract: A continuous signal of a radio frequency source is connected to an antenna using at least one mixer to generate and analyze radar pulses. To generate a radar pulse, the at least one mixer is briefly placed into a state of low throughput loss. After the radar pulse is generated and transmitted, the at least one mixer is switched over to a receive mode to analyze a mixed signal formed by a receive signal, in particular at least one radar pulse reflected by an object, and the continuous signal of the radio frequency source.
    Type: Application
    Filed: March 28, 2002
    Publication date: November 7, 2002
    Inventor: Dirk Steinbuch
  • Patent number: 6281833
    Abstract: A timing and control method and apparatus (111) for performing precise range rate aiding includes a range gate delay means (114) for generating an estimate of the range gate delay (135) each pulse repetition interval as a function of the initial range (134) and velocity (133) provided by a processor (104). The range gate delay (135) is converted into a coarse delay (138) defining the integral number of clock cycles preceding the range gate, and a fine delay (139) for positioning a range gate to within a fraction of a clock cycle. Fine temporal control is achieved using programmable delay lines (117) and (118), which retard various control signals, including the system clock signal (131), in accordance with the fine delay (139). A modified signal (126) then drives a counter means (119) which outputs a signal (128) that defines an analog-to-digital sampling window beginning at the elapse of the range gate delay (135).
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: August 28, 2001
    Assignee: Science and Applied Technology, Inc.
    Inventors: Richard C. Pringle, Charles T. McMurray
  • Patent number: 6243037
    Abstract: A tracking method for a signal echo system, including generating a plurality of gates for respective propagation modes on the basis of a target state prediction for a dwell time, and generating a target state estimate for the dwell time on the basis of target measurement points which fall within the gates.
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: June 5, 2001
    Assignee: The Commonwealth of Australia
    Inventors: Graham William Pulford, Robert Keith Jarrott, Robin John Evans
  • Patent number: 6232912
    Abstract: The invention particularly relates to the detection of fast-flying targets by means of an HPRF radar system that operates with a plurality of switchable pulse-repetition frequencies (PRFs). In the method, a high velocity resolution is attained, which permits a reliable detection of a multiple-target situation. At the same time, a precise range determination is attained with a high range resolution by means of a pure transit-time measurement of the pulses. The length of the used range gates is selected to correspond to the anticipated target length.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: May 15, 2001
    Assignee: Daimler-Benz Aerospace AG
    Inventor: Dieter Nagel
  • Patent number: 6111537
    Abstract: Method for reducing false target echo indications in a pulse Doppler radar having at least two different pulse repetition frequencies during the period in which the main beam of the radar illuminates a target. A target which is detected gives rise to a number of primary detections in each PRF. The method includes use of at least one variable criterion and a final criterion, which are both of the M/N type. The factor M in the variable criterion is initially greater than the factor M in the final criterion. The method also includes the feature that primary detections which are all to be found in the same range gate in a number of PRF's, which number is equal to the factor M in the variable criterion, are approved as targets in this range gate.
    Type: Grant
    Filed: March 15, 1999
    Date of Patent: August 29, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Bengt Andersson
  • Patent number: 5977905
    Abstract: Coherent bursts of N wideband, low repetition frequency width-modulated pulses are transmitted, and they are received with pulse compression and then sampling. For each range gate and each speed hypothesis, a selection is made of the corresponding samples of N repetitions of a burst after compensation for the migration in distance. On each set of N samples, for a given speed hypothesis, a Fourier transform and a threshold-setting operation are performed. The distance and the unambiguous speed of the detected targets are then extracted.
    Type: Grant
    Filed: July 8, 1997
    Date of Patent: November 2, 1999
    Assignee: Thomson-CSF
    Inventor: Fran.cedilla.ois Le Chevalier
  • Patent number: 5907301
    Abstract: A procedure and a device for controlling, in a radar unit for the measurement of target data, the transmission of radar pulses and the reception of target echoes originating from the transmitted radar pulses, in such a way that the performance of the radar unit increases, in order thereby to gain a longer range during a period of time. The period of time is preferably repeated continually. The period of time is divided into a first and a second partial period of time where the first and the second partial periods of time are each at least twice as long as a pulse repetition interval which is used during the first partial period of time. During the first partial period of time the radar unit is controlled so that it transmits radar pulses for the measurement of target data with a higher energy content than what is possible in a steady state.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: May 25, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Bengt Andersson
  • Patent number: 5774091
    Abstract: A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with atypical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: June 30, 1998
    Assignee: The Regents of the University of California
    Inventor: Thomas E. McEwan
  • Patent number: 5546088
    Abstract: The present invention pertains to a radar range finder for high-precision, contactless range measurement, which is based on the FMCW principle and operates with digital signal processing at a limited frequency shift. One exemplary embodiment is described.
    Type: Grant
    Filed: October 5, 1994
    Date of Patent: August 13, 1996
    Assignee: Deutsche Aerospace AG
    Inventors: Gunther Trummer, Richard Korber
  • Patent number: 5440311
    Abstract: A radar transmits dispersed pulses in which the subpulses are modulated by first and second mutually complementary code sequences, the autocorrelation functions of which are selected so that, in the sum of their autocorrelation functions, the main range lobes add, and the range sidelobes cancel. The received pulses with their Doppler sidebands are applied to a plurality of channels, each of which (except one) contains a mixer-oscillator combination that removes a specific Doppler phase shift along the range dimension at a different channel frequency. One channel has no mixer-oscillator because it is centered at a zero channel frequency. Within each channel, the received signals modulated by the first and second codes are matched-filtered by filters matched to the first and second codes, respectively, to produce first and second time-compressed pulses, each including (a) a main lobe representing the target range, and (b) undesirable range sidelobes.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: August 8, 1995
    Assignee: Martin Marietta Corporation
    Inventors: John J. Gallagher, Harry Urkowitz
  • Patent number: 5376939
    Abstract: A radar system simultaneously transmits first and second signals toward a target at higher and lower carrier frequencies, respectively. Each carrier is phase-modulated by a set of pulses. The first set of pulses is dispersed in time, and the second set of pulses is mutually complementary thereto. The transmitted pulses are reflected by the target and received simultaneously. The received signals are processed separately by Doppler filtering. Each Doppler-filtered return is code-matched filtered, and the filtered signals in each Doppler channel are summed with the corresponding Doppler-and-code-matched-filtered signals originating from the other transmitted frequency, to form range signals. Each range signal has its main lobe enhanced and its sidelobes suppressed by the summing of the code-matched-filtered mutually complementary echoes.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: December 27, 1994
    Assignee: Martin Marietta Corporation
    Inventor: Harry Urkowitz
  • Patent number: 5357331
    Abstract: An energy pulse capture system senses, receives, and processes signals reflected from a target. In an illustrative embodiment, light pulses are reflected off of a target, received by optical equipment, converted into analog electrical signals, and then processed to obtain information therefrom. The invention basically identifies targets by measuring the time delay between a transmitted signal and a received or "return" signal. The invention includes a windowing system to more efficiently process digitized electrical signals representing the return signals. The windowing system effectively defines a "window" in memory within which the return signal is stored, and "locks" on to this window to reduce time spent searching for the return pulses among other data. In another aspect of the invention, a real time return system is used to more efficiently process the electrical signals representing the return pulses.
    Type: Grant
    Filed: March 24, 1993
    Date of Patent: October 18, 1994
    Inventor: Stuart W. Flockencier
  • Patent number: 5293168
    Abstract: The invention provides a method of determining the range of a radar signal reflecting object by utilizing a radar frequency carrier wave modulated by a first short code having a first repetition rate and a second code having a bit rate equal to the first code repetition rate. A received echo is first passed to an analogue correlator for correlation against a delayed version of the first code, and the output of the analogue correlator is fed to a digital correlator for correlation therein against the second code. In this way, the high bandwidth (greater range resolution) of analogue correlation can be combined with the lower bandwidth (longer ambiguity function) of digital correlation to provide high resolution target detection without ambiguity and at a fast rate without the need for a very large number of correlators.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: March 8, 1994
    Assignee: GEC-Marconi Limited
    Inventor: Alistair R. Faulkner
  • Patent number: 5181039
    Abstract: A system for determining the trajectory of a missile and the minimum miss distance with respect to a target aircraft, comprises two transmitters on the aircraft each cooperating with four receivers on the aircraft. Each transmitter radiates a succession of pulses each having a very short duration of the order of 2 nanoseconds and each having a shape approximating to a single sine wave. The transmitted pulses are reflected from the missile and received by the receivers each of which is accurately time gated so that the received signal is sampled at a predetermined time delay after the radiation of each transmit pulse. A time delay corresponds to a particular missile range, and by gating at different delays the sampled signals indicate when the missile enters or leaves a plurality of range envelopes surrounding the target. Processing of the sampled signals enables the missile trajectory and minimum miss distance to be computed.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: January 19, 1993
    Assignee: Cambridge Consultants Limited
    Inventors: Gordon K. A. Oswald, Christopher S. Neal, Alan T. Richardson
  • Patent number: 5173706
    Abstract: A multipurpose system provides radar surveillance for air traffic control purposes. The system includes four separate active phased-array antennas, each with .+-.45.degree. coverage in azimuth, from 0.degree. to 60.degree. in elevation. Each antenna element of each phased-array antenna is coupled by a low-loss path to the solid-state amplifier associated with a transmit-receive (TR) module. Each antenna produces a sequenc of pencil beams, which requires less transmitted power from the TR modules than a fan beam, but requires more time beacuse the pencil beam must be sequenced to cover the same volume as the fan beam. In order to scan the volume in a short time, the PRF is responsive to the elevation angle of the beam, so higher elevation angles use a higher PRF. Low elevation angle beams receive long transmitter pulses for high power, and pulse compression is used to restore range resolution, but the long pulse results in a large minimum range within which targets cannot be detected.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: December 22, 1992
    Assignee: General Electric Company
    Inventor: Harry Urkowitz