Patents Examined by T. H. Tubbesing
  • Patent number: 5206652
    Abstract: A height measurement system uses an inexpensive ultrasonic height measuring evice to provide an apparent height of a descending airborne object. To compensate for movement of the object during the ultrasonic measurement, a Doppler radar velocity measuring device determines the vertical velocity in a short measurement period. The measured vertical velocity is used to determine the vertical distance travelled during the ultrasonic measurement and to compensate therefor by converting the apparent height to a true height of the descending object. Updates of the true height may be obtained by storing the vertical velocity and retrieving the vertical velocity for multiplication by a time value to obtain an updated value of the true height.
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: April 27, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Reed W. Hoyt, John F. Lanza
  • Patent number: 5204681
    Abstract: A radio frequency automatic identification system detects targets which include solid resonators resonating at several frequencies, attributing information to the frequencies at which the target resonates. Preferred resonators are quartz crystals, which may be made by a process of heating quartz to soften it and cutting crystals to approximate size and resonant frequency. Resonators produced by such a process are measured to determine their actual resonant frequency, and preferably the crystals are sorted into predetermined frequency windows in accordance with their measured resonant frequency. A set of resonators having frequencies corresponding to predetermined data is selected from the sorted groups of resonators and incorporated into a target. The preferred target is an ink-like material having a plurality of resonators disposed in a matrix which is radio frequency transparent at the frequency of interest.
    Type: Grant
    Filed: September 24, 1991
    Date of Patent: April 20, 1993
    Assignee: Gordian Holding Corporation
    Inventor: Morton Greene
  • Patent number: 5204680
    Abstract: A radar reflecting target comprises a plurality of reflecting elements spread along at least one linear physical dimension of the target, the elements being differingly spaced in the direction normal to said dimension so that respective retro-reflections by the elements of radio frequency energy from a remote soucre on a line of sight at an angle to said dimension, have differing phases and tend to cancel each other out. The invetion may be applied to single or two dimensional surfaces on such vehicles as ships or aeroplanes.
    Type: Grant
    Filed: October 24, 1991
    Date of Patent: April 20, 1993
    Assignee: Racal Defence Electronics (Radar) Limited
    Inventor: Marcus L. Allington
  • Patent number: 5204684
    Abstract: A digital telemetry device includes synchronous counters monitored by a clock. The counters are connected, on the one hand, to two comparators and, on the other hand, to a buffer memory. The comparators generate a telemetry mark which makes it possible to form a tracking window. The buffer memory stores or transmits the value of the counters whenever it receives an echo presence signal.The comparators work with most significant bits (MSB) to generate the telemetry mark, whilst the buffer memory works with least significant bits (LSB) which make it possible to determine the position of the target in relation to the center of the telemetry mark, for example by the use of a "complement-on-two" code.
    Type: Grant
    Filed: October 3, 1984
    Date of Patent: April 20, 1993
    Assignee: Thomson - CSF
    Inventor: Yves Caudroy
  • Patent number: 5202689
    Abstract: An adjustable focal length reflector for operation in space includes a membrane having a reflective surface. The membrane is subjected to incident radiation pressure. An assembly is located at the perimeter of the membrane to exert force on the membrane to counteract the incident radiation pressure in order to vary the focal length of the reflective surface. In a preferred embodiment the assembly includes an inflatable torus whose internal pressure is varied to vary the amount of force exerted on the membrane.
    Type: Grant
    Filed: August 23, 1991
    Date of Patent: April 13, 1993
    Assignee: APTI, Inc.
    Inventors: Robert W. Bussard, Thomas H. Wallace
  • Patent number: 5200754
    Abstract: The present invention is a computational method, defined by a computational algorithm, that automatically corrects synthetic array radar (SAR) focus errors more accurately than conventional procedures. The novel feature is that the present method estimates residual phase errors by forming fourth-order subarray products in lieu of conventional second-order subarray products. As a result, a pull-in range for residual phase errors is vastly improved. The present invention advances the state of the art by creating a SAR autofocus method that has an unlimited pull-in range for both a quadratic and a cubic phase errors. The invention thus extends the operational range and resolution of SAR systems, and enables the effective use of the SAR sensor with a limited (less expensive) motion compensation subsystem. The present invention provides for a phase difference autofocus method that estimates the residual quadratic and cubic phase error that often requires only one autofocus iteration.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: April 6, 1993
    Assignee: Hughes Aircraft Company
    Inventor: Yoji G. Niho
  • Patent number: 5198819
    Abstract: A weather radar display system and method for obtaining and storing radar return data for a plurality of horizontal and vertical sweeps, each horizontal sweep occurring at a different tilt angle and each vertical sweep occurring at a different azimuth angle. The radar return data is displayed as plan views in a plurality of separate display sections, each corresponding to a plurality of separate horizontal sweeps in one embodiment and to a plurality of separate vertical sweeps in a second embodiment. Radar return data in one display section (horizontal or vertical) is displayed with a variety of colors to represent precipitation intensity. Radar return data in remaining display section (horizontal or vertical) is displayed as a first color with edge returns displayed in second color to differentiate the remaining sections.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: March 30, 1993
    Assignee: Thermwood Corporation
    Inventor: Kenneth J. Susnjara
  • Patent number: 5192955
    Abstract: A target tracking system and methods that can isolate and maintain stable track on a selected target in multiple-target environment. In multiple-target environments, the signal returns received at the sum and difference channels are composites of individual targets. By decomposing received signals into individual components, angle measurements to each target are computed, and consequently, a specified target is isolated and accurately tracked in a stable manner. The present invention provides for apparatus and methods that compute angle measurements to each individual airborne target in a multiple target environment. The composite return signals from a number of targets that are closely spaced in Doppler are decomposed into their individual components, and hence, tracking measurements to each target are obtained without interference from other targets. The present invention may be used to determine the angular position of individual airborne targets within a multiple target environment.
    Type: Grant
    Filed: September 25, 1991
    Date of Patent: March 9, 1993
    Assignee: Hughes Aircraft Company
    Inventor: Bao N. Hoang
  • Patent number: 5191348
    Abstract: A method and apparatus for performing simple, rapid and accurate tests to determine the operational status of police band radar detecting equipment. A low-power, hand-held transmitter capable of transmitting signals within police radar bands for testing the receiver section and alerting circuitry of a radar detector.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: March 2, 1993
    Inventors: Robert W. Brocia, Marie Dagata
  • Patent number: 5191345
    Abstract: In a system for the exchange of data by microwaves between a fixed station and a mobile station or portable badge, the information bit rate is limited, in the standby state, by the low power consumption of the badge and the high output impedance of the modem. To increase the information bit rate of the modem of a badge, the information processing circuit associated with the modem sends the modem an activation signal to reduce its output impedance. The means implemented are transistors that switch over the load of the detector transistor or of the amplifier transistor.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: March 2, 1993
    Assignee: Thomson Composants Microondes
    Inventors: Marc Camiade, Pierre Quentin, Pierre Savary, Jean-Philippe Brandeau
  • Patent number: 5191343
    Abstract: An improved radar system utilizing the principle of nonlinear contact effects for detecting and identifying a target, includes two radar transmitters (12,16) at least one of which is a baseband pulse radar transmitter. Both transmitters illuminate the same target and the signals from each transmitter are mixed in a nonlinear junction (40) of the target. Mixing the two signals provides a target return signal whose frequency spectrum contains cross product frequency components having high resolution target data due to the broad spectral content of the baseband pulse, and thus provides a system capable of detecting and identifying the illuminated target.
    Type: Grant
    Filed: February 10, 1992
    Date of Patent: March 2, 1993
    Assignee: United Technologies Corporation
    Inventors: Paul M. Danzer, Michael J. Brienza
  • Patent number: 5189428
    Abstract: Disclosed is a method for the processing of a signal received directly or indirectly from a transmitter, sending out pulses that are digitally encoded according to a transmission code of N instants; said processing comprising notably an operation of filtering that is matched with the transmitted signal and an operation of detection by the comparison of the post-filtering level of the signal with a so-called detection threshold; wherein the signal received is subjected to two processing operations A and B, the processing operation A comprising a self-correlation and the processing operation B comprising an intercorrelation with a mismatched code having a length at least equal to 3N, the function of intercorrelation of this mismatched code with the transmission code giving a major central lobe and at least N side lobes that are zero on either side of this major lobe; and wherein it is decided that there is a detection relating to one of the instants of the correlation or of the intercorrelation only if the leve
    Type: Grant
    Filed: December 19, 1991
    Date of Patent: February 23, 1993
    Assignee: Thomson-CSF
    Inventors: Jacky Bouvet, Anne Chapelet
  • Patent number: 5189427
    Abstract: When linearizing FMCW radars it is customary to produce a synthetic target signal independently of the radar signal and to use the synthetic target signal to linearize the sweeping of the transmitted VCO frequency or the sampling of the radar IF signal to be analyzed. In order to reduce the overall number of microwave RF components, the present invention uses one mixer (18) to produce the radar IF and linearizing IF. In one embodiment an RF STALO (32) is coupled by a directional coupler (34) into the return path of the radar signal. In other embodiments (not shown) the mixer comprises a dc biased waveguide harmonic mixer and the STALO generates a lower frequency which is applied to the mixer by way of either the bias port or the radar IF output port. The linearizing arrangements (28) disclosed are based on known designs.
    Type: Grant
    Filed: July 9, 1991
    Date of Patent: February 23, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Andrew G. Stove, Michael B. Williams
  • Patent number: 5187484
    Abstract: The frequency-versus-time characteristic of the output signal of a swept-frequency radar is linearized by determining departures from linearity of the phase-versus-time characteristic of the beat signal obtained between an actual return from a selected radar target and a sample of the current radar output signal, and applying oppositely-directed corrections to the frequency-versus-time characteristic. The relevant beat signal is selected from the output signal of a mixer (8) by performing special analysis in a Fast Fourier Transform (FFT) calculating circuit (15) and then performing an inverse FFT on a windowed portion of the FFT obtained. A second or higher-order polynomial is then fitted to the phase-versus-time characteristic of the selected beat signal after it has been expressed as time versus phase, and correction terms are derived from the coefficients of this polynomial. The radar output signal is generated by a voltage-controlled oscillator (1) controlled by a control voltage generator (7).
    Type: Grant
    Filed: January 31, 1992
    Date of Patent: February 16, 1993
    Assignee: U.S. Philips Corporation
    Inventor: Andrew G. Stove
  • Patent number: 5185608
    Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic countermeasures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome an a "axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radome-induced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: February 9, 1993
    Assignee: Raytheon Company
    Inventor: Jerome H. Pozgay
  • Patent number: 5184137
    Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic counter-measures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome on a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radome-induced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: February 2, 1993
    Assignee: Raytheon Company
    Inventor: Jerome H. Pozgay
  • Patent number: 5184134
    Abstract: A phase difference autofocus method that only requires one FFT for estimating a phase error in the entire synthetic array radar data. The phase difference autofocus method of the present invention automatically and efficiently estimates phase errors from radar signals, allowing a well focused SAR image to be produced. The present method comprises the following steps. First, each range bin is divided into two subarrays. Next, the two subarrays are complex-conjugate multiplied together to produce a cross spectrum of the two submaps produced by the subarrays. Then, the phases of each cross spectrum are aligned with an accumulated sum of the cross spectrums from previous processed range bins. The phase aligned cross spectrum is then added to the accumulated cross spectrum sum. All range bins are processed to get a final cross spectrum sum. Next, a single FFT is performed on the final cross spectrum sum to produce the cross correlation function. Then, the cross correlation function is magnitude-detected.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: February 2, 1993
    Assignee: Hughes Aircraft Company
    Inventors: Yoji G. Niho, Eric W. Day, Tammy L. Flanders
  • Patent number: 5182563
    Abstract: An enhanced performance Mode S interrogator that includes a matched channel receiver. The receiver includes equiripple-phase response filters with finite peaks of attenuation. This new class of filters provides a faster rise of attenuation than all-pole filter while extending the equiripple delay further into the stopband.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: January 26, 1993
    Assignee: Westinghouse Electric Corp.
    Inventors: Herman J. Blinchikoff, Ann C. Schofield
  • 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: 5179385
    Abstract: A navigation aid is provided comprising a radar antenna, a position sensor, a compass, map/chart data, a display, and a controller. The controller determines whether the display depicts a chart, a radar sweep or both. Preferably, the visual navigation aid includes a point of interest feature, wherein at least one point of interest is visually selected on the chart or radar sweep by a cursor or the like. The controller also computes the location of the selected point of interest for display on the chart or radar sweep. In another aspect, the invention comprises methods for inputting and displaying a point of interest on a chart or radar sweep.
    Type: Grant
    Filed: January 2, 1992
    Date of Patent: January 12, 1993
    Assignee: International Marine Industries, Inc.
    Inventors: Thomas M. O'Loughlin, Douglas W. Low, Neil Titcomb