Sensitivity Time Control (stc) Patents (Class 342/205)
  • Patent number: 9720077
    Abstract: A method and system for adjusting a gain from a receiver antenna. The method may include accessing a radio altimeter data structure for antenna gain data. The antenna gain data may be associated with one or more antennas including a receiver antenna. Additionally, the method may include receiving aircraft maneuver data from a reference system. Furthermore, the method may include adjusting a gain from the receiver antenna based at least on the aircraft maneuver data.
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: August 1, 2017
    Assignee: Rockwell Collins, Inc.
    Inventor: Madjid N. Sarpoolaki
  • Patent number: 9465106
    Abstract: Embodiments of the invention are directed toward attenuation correction of radar data. Atmospheric attenuation is a function of atmospheric water drop size and temperature. A number of different theoretical models are available to mathematically describe the particle drop shape that influences attenuation estimation. Each of these models has proven effective in different scenarios. It can be difficult, however, to predict which theoretical model to use. The total differential phase gives an idea of the attenuation, but it depends on the model. Moreover, the total attenuation along a rain path must be apportioned to different parts of the radar path in order to correct for attenuation along a radar path. Embodiments of this invention allows for a system to apportion the attenuation to different parts of the radar beam. Embodiments of the invention also allow for optimization of a number of different theoretical models for both drop size and temperature.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: October 11, 2016
    Assignee: Colorado State University Research Foundation
    Inventors: Chandrasekaran Venkatachalam, Sanghun Lim
  • Patent number: 8755037
    Abstract: An optical device is disclosed that may be employed in distance measuring devices. In at least one embodiment, the optical device includes a control unit that is adapted to cause at least one control signal generator unit to generate at least one control signal according to a predetermined temporal function on the basis of an elapsed time from a predetermined point in time. On the basis of the generated at least one control signal, at least one parameter of a receiver unit may be adjusted during the travel time of the optical pulse, wherein the at least one parameter affects the dynamic range of the receiver unit. In this way, the dynamic range of the receiver unit may be increased. A method is further disclosed for operating such an optical device, along with a distance measuring device including such an optical device and a surveying instrument including such a distance measuring device.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: June 17, 2014
    Assignee: Trimble AB
    Inventor: Yuri P. Gusev
  • Patent number: 8599060
    Abstract: The present invention relates to a system (300) for reducing or cancelling unwanted signals when detecting objects of interest with a detection system (200). The detection system thereby is an antenna based system using two or more receive beams as echo response to an emission signal. The system (300) for reducing or cancelling unwanted signals comprises an input means (310) adapted for obtaining from said antenna system (210) receive signals from a first receive beam and receive signals from at least one second receive beam responsive to the same emission signal. It furthermore comprises a coupling means (320) adapted for coupling the receive signals from the first receive beam to the receive signals from the at least one second receive beam, so as to obtain a detection signal for the objects of interest with suppressed unwanted signal contribution.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: December 3, 2013
    Assignee: Intersoft Electronics NV
    Inventor: P. G. Marcel Vanuytven
  • Patent number: 8456352
    Abstract: Methods and apparatus to receive radar return information from signals transmitted by a radar, process the radar return information to identify sea clutter, process the sea clutter to fit an ellipse to arrange horizon of the sea clutter as a function of azimuth to determine a sea state, and select sensitivity time control (STC) attenuation of the sea clutter based upon the sea state.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: June 4, 2013
    Assignee: Raytheon Company
    Inventor: Thomas E. Wood
  • Publication number: 20120293361
    Abstract: Sidelobe suppression methods and systems for use in processing radar video streams generated by rotational radar antenna scanners. The sidelobe suppression methods function in parallel with traditional Sensitivity Control (SC) processing by selectively reducing sensitivity where necessary depending on sidelobe suppression schemes that can be either directional, omni-directional (non-directional), or a combination of these.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 22, 2012
    Inventors: Robert Stephen Mowbray, Roger Phillips
  • Patent number: 8223065
    Abstract: A method according to an aspect of the disclosure is for partitioning a radar acquisition volume, the method comprising the steps of: determining an allocated time to search an unpartitioned volume; determining a number of beam rows in an unpartitioned acquisition face; determining an average per-row search time for searching the angular region based on the determined allocated time and determined number of beam rows in an unpartitioned acquisition face; determining a number of beam rows in an allotted acquisition period that is searchable based on the average per-row search time; calculating a maximum elevation extent based on the number of beam rows in the allotted acquisition period; and searching an angular extent of the search volume based on the calculated maximum extent.
    Type: Grant
    Filed: September 20, 2010
    Date of Patent: July 17, 2012
    Assignee: Lockheed Martin Corporation
    Inventor: Mark Friesel
  • Publication number: 20120154208
    Abstract: Methods and apparatus to receive radar return information from signals transmitted by a radar, process the radar return information to identify sea clutter, process the sea clutter to fit an ellipse to arrange horizon of the sea clutter as a function of azimuth to determine a sea state, and select sensitivity time control (STC) attenuation of the sea clutter based upon the sea state.
    Type: Application
    Filed: December 17, 2010
    Publication date: June 21, 2012
    Applicant: Raytheon Company
    Inventor: Thomas E. Wood
  • Patent number: 8174435
    Abstract: Methods and apparatus to provide computing, using a processor, sea clutter threshold bias values as a function of range and azimuth, receiving a first shape corresponding to a first region of sea clutter about a radar, combining the sea clutter threshold bias values with the first shape to provide non-isotropic sensitivity time control (STC) for the radar, and outputting radar return for display with sea clutter suppressed in the first shape.
    Type: Grant
    Filed: June 1, 2010
    Date of Patent: May 8, 2012
    Assignee: Raytheon Company
    Inventors: Amir W. Habboosh, Nicholas F. Willis, Thomas E. Wood
  • Patent number: 8004451
    Abstract: A method and apparatus are provided for operating a microwave detector for detecting intruders within a secured area. The method includes the steps of selecting a noise floor based upon a setting of a range setting potentiometer, detecting a magnitude of a signal reflected from a test subject within the secured area that exceeds the selected noise floor and establishing a threshold value for detecting an intruder based upon the magnitude of the detected signal and sensor mounting height.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: August 23, 2011
    Assignee: Honeywell International Inc.
    Inventors: XiaoDong Wu, Roy Phi, Dave Eugene Merritt
  • Patent number: 7796082
    Abstract: Methods and apparatus to provide Log-Amp-detected radar sea clutter voltage modeled by a polynomial, such as a cubic polynomial, and using that model as a basis for sea clutter reduction filtering. In an exemplary embodiment, a navigational radar includes an STC filter design based on the cubic sea clutter modeling.
    Type: Grant
    Filed: February 8, 2007
    Date of Patent: September 14, 2010
    Assignee: Raytheon Company
    Inventor: Thomas E. Wood
  • Patent number: 7693499
    Abstract: In a transmission path, an input signal is amplified in a manner dependent on a digital control word present and is processed by an arrangement for signal processing to form an output signal. A digital setting word is read out from a memory device in a manner dependent on the digital control word, setting signals being derived from said setting word. The gain setting of the amplifier and the operating mode of the arrangement for signal processing are influenced by the setting signals.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: April 6, 2010
    Assignee: Infineon Technologies AG
    Inventor: Rainer Koller
  • Patent number: 7576683
    Abstract: In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: August 18, 2009
    Assignee: Honeywell International Inc.
    Inventors: Steven H. Thomas, Glen B. Backes, Timothy J. Reilly
  • Patent number: 7551988
    Abstract: A designated function or “golden” slot for implementing and managing re-configurable SDR modules is provided. In an embodiment, the slot includes at least one radio frequency (RF) front end for providing an interface with at least one antenna. In addition, the slot may include at least one slot modem coupled to the RF front end for implementing at least one designated function and at least one input/output (I/O) module coupled to the slot modem. The designated function or “golden” slot is capable of implementing and managing the at least one designated function in a re-configurable module during standard and emergency operations.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: June 23, 2009
    Assignee: Rockwell Collins, Inc.
    Inventors: Joel M. Wichgers, Demetri Tsamis, Terrence L. Leier, Gregory A. Arundale
  • Publication number: 20090096663
    Abstract: In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.
    Type: Application
    Filed: August 7, 2006
    Publication date: April 16, 2009
    Inventors: Steven H. Thomas, Glen B. Backes, Timothy J. Reilly
  • Publication number: 20090085799
    Abstract: In a pulse radar system where received echo pulses are expanded in time by multiplication with sampling pulses and subsequent integration, the effect of disturbances on the integration is reduced by using a sample and hold circuit having a switch and a hold capacitor and wherein the switch is closed only when a sampling pulse is applied for the multiplication.
    Type: Application
    Filed: September 16, 2008
    Publication date: April 2, 2009
    Inventor: Gabriel Serban
  • Patent number: 7499796
    Abstract: A driver information device with a map display is designed in such a way as to make the map display clear and easy to read. This is achieved, in cases where multiple special objects are situated at one location on the map, through the use of an indicator symbol representing such special objects, with a selection menu for selecting individual special objects, instead of displaying an individual symbol for each one of them.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: March 3, 2009
    Assignee: Robert Bosch GmbH
    Inventors: Holger Listle, Andre Barkowski
  • Patent number: 6972709
    Abstract: A transceiver that includes a radio frequency source comprised of a monolithic millimeter wave integrated circuit. The transceiver generates a signal of a first frequency, which is then converted to a signal of a second frequency as the signal is conveyed through the transceiver. The value of the second frequency exceeds that of the first frequency.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: December 6, 2005
    Assignee: Yazaki North America, Inc.
    Inventors: Jake Deem, Terry B. Wilson
  • Patent number: 6965341
    Abstract: A stepped-frequency chirped waveform improves SAR groundmapping for the following reasons. Range resolution in SAR image is inversely proportional to the transmitted signal bandwidth in nominal SAR systems. Since there is a limit in the transmitted bandwidth that can be supported by the radar hardware, there is a limit in range resolution that can be achieved by processing SAR data in conventional manner. However, if the frequency band of the transmitted signal is skipped within a group of sub-pulses and received signal is properly combined, the composite signal has effectively increased bandwidth and hence improvement in range resolution can be achieved. The proposed new and practical approach can effectively extend the limit in range resolution beyond the level that is set by the radar hardware units when conventional method is used.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: November 15, 2005
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Kwang Myung Cho, Leo H. Hui
  • Patent number: 6903679
    Abstract: A video amplifier for a radar receiver includes a temperature compensating attenuator. The attenuator includes a temperature sensitive device, such as a thermistor, arranged in a voltage divider network and is coupled in cascade between two filter stages. Each of the filter stages has a bandpass characteristic in order to filter low-frequency leakage signals and provide sensitivity control based on frequency and thus range, while also filtering high frequency signals to reduce aliasing.
    Type: Grant
    Filed: August 16, 2001
    Date of Patent: June 7, 2005
    Assignee: Raytheon Company
    Inventors: James T. Hanson, Walter Gordon Woodington, Michael Joseph Delcheccolo, Joseph S. Pleva, Mark E. Russell, H. Barteld Van Rees
  • Patent number: 6842139
    Abstract: A separation frequency detector circuit and a method for detection of a separation frequency in a radar level gauge. A first circuit element (1) is arranged to receive a first clock frequency, and a second clock frequency. An instantaneous value of the first clock frequency will be transferred to and held at an output Q of the first circuit element (1) once each period of the second clock frequency. A predetermined value will be transferred to and held at an output Q of a second circuit element (3) triggered by the output Q of the first circuit element (1), and the predetermined value will be cleared from the output Q of the second circuit element (3) a predetermined time period after being triggered. An output is obtainable as a short pulse with a leading edge which will be synchronized with the first change of the leading signal edge of the first circuit element (1).
    Type: Grant
    Filed: October 20, 2003
    Date of Patent: January 11, 2005
    Assignee: Saab Rosemount Tank Radar AB
    Inventor: Leif Nilsson
  • Patent number: 6741203
    Abstract: A system and method for adapting weather radar gain is disclosed. The system and method includes estimating a freezing altitude. The system and method also includes determining, based on the freezing-altitude estimate, the altitude of more than one atmospheric layer. The system and method further includes determining the proportion of a radar beam sample in each atmospheric layer and adjusting the radar gain, based on the proportion.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: May 25, 2004
    Assignee: Rockwell Collins
    Inventor: Daniel L. Woodell
  • Publication number: 20030100285
    Abstract: A sensor front end for an electronic radar sensor is disclosed that provides for a lower parts count while providing technical functionality by using multifunction parts, i.e., parts that are used both in transmitting and receiving. The sensor front end includes a continuous wave signal source that functions as a signal source when the front end is transmitting a signal and as a local oscillator when the front end is receiving a signal. The sensor front end also includes a tri-mode mixer that functions as a phase-modulator and transmit switch when the front end is transmitting a signal and as a mixer/down-converter when the front end is receiving a signal. The sensor front end further includes a common aperture antenna that acts as both a transmitting antenna for transmitting a sensor signal and for receiving a reflected signal from a object.
    Type: Application
    Filed: November 28, 2001
    Publication date: May 29, 2003
    Applicant: TYCO Electronics Corporation
    Inventor: Kenneth V. Puglia
  • Patent number: 6404378
    Abstract: A device for increasing the dynamic range of frequency-modulated continuous-wave radar includes a transmitter, a send/receive antenna, a receiver circuit and a circulator. The circulator relays the transmission signals of the transmitter to the send/receive antenna and sends the echo signals of a target object to the input of the receiver circuit, which generates on the basis of the transmission signals and echo signals an intermediate frequency signal having a differential frequency corresponding to the distance from the target object. A reflected power canceler circuit equipped with a control amplifier is provided between the input and output of the receiver circuit. The frequency response of the control amplifier is selected so that the degree of suppression drops to a predeterminable extent with an increase in differential frequency above the cut-off frequency of the control amplifier.
    Type: Grant
    Filed: April 24, 2000
    Date of Patent: June 11, 2002
    Assignee: DaimlerChrysler AG
    Inventor: Klaus Solbach
  • Patent number: 6104197
    Abstract: An apparatus for acquiring waveform data from a metallic transmission cable under test includes a transmitter for generating interrogating pulses for examining a segment or segment lengths of the transmission cable under test. A variable gain receiver receives a return signal from the segment or segment lengths of the cable and generates at least two gain segment acquisitions of waveform data representative of the signal from each segment or segment lengths with each gain segment acquisition of waveform data being generated with a different receiver gain. A controller operating under program control initiates the generation of interrogating pulses, establishes the receiver gain for each gain segment acquisition of waveform data, and controls the gain segment acquisitions of waveform data over the segment or segment lengths. An event table is created containing event characterization data for each gain segment.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: August 15, 2000
    Assignee: Tektronix, Inc.
    Inventor: Phillip F. Kochan
  • Patent number: 6087977
    Abstract: An improved performance receiver associated with a radar system for detecting targets over a specified range area whereby the receiver, which is responsive to a return signal corresponding to an actual target or a false target, includes: an attenuator for attenuating an amplitude associated with the return signal; sensitivity time control means coupled to the attenuator wherein the attenuation is coordinated to the sensitivity time control means and the attenuation of the return signal is selectively variable such that the amplitude of the return signal is attenuated to a first level at closer ranges of the specified range area and attenuated to a second level at farther ranges of the specified range area, the first level being greater than the second level; a mixer for downconverting the return signal to a signal exhibiting an intermediate frequency; a detector for extracting a target video signal from the downconverted return signal; detection threshold setting means for generating a detection threshold sig
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: July 11, 2000
    Assignee: Cardion Newco, Inc.
    Inventor: David P. Rost
  • Patent number: 5905459
    Abstract: A radar system and method for operation of the same in a manner in which the false alarm rate is stabilized is provided. The system includes an automatic gain control (AGC) processing function which is utilized to control the pre-processed false alarm rate such that the displayed false alarm rate is substantially intolerant to temperature fluctuations.
    Type: Grant
    Filed: April 18, 1997
    Date of Patent: May 18, 1999
    Assignee: Honeywell Inc.
    Inventor: Brian Paul Bunch
  • Patent number: 5805107
    Abstract: For less expensive estimation the impulse response x.sub.MOS of a high-resolution, band-limited radar channel in a radar station operating with an expanded transmitted pulse a(t), from a received signal e, over which a correlated or uncorrelated additive interference signal n can be superimposed, with the use of knowledge about the spread code c and the use of a channel estimator with which a so-called linear, optimum unbiased estimation of the radar channel impulse response x.sub.MOS is performed in a time range covering M range gates of interest, the linear, optimum estimation in the unbiased channel estimator is modified in such a way that the pulse response x.sub.MOS of the band-limited radar channel is determined according to the basic principle of a multiplication of the sampled received signal e and an inverse estimation matrix A.sub.E.sup.-1. The matrix A.sub.E is formed by the extension of the rectangular matrix represented by the components c.sub.
    Type: Grant
    Filed: April 18, 1997
    Date of Patent: September 8, 1998
    Assignee: Deutsche Forschungsanstalt fur Luft-Und Raumfahrt e.V.
    Inventors: Arno Schroth, Tobias Felhauer, Walter Baier
  • Patent number: 5416501
    Abstract: A pair of holes are formed with a predetermined space therebetween on a long and narrow base plate. An adhesive is applied to the surface of the base plate. Head substrates each having a row of thermal resistors on the surface thereof are placed on the adhesive on the base plate such that the joint of the head substrates is positioned between the pair of holes of the base plate. The adhesive is hardened in the state in which the head substrates are pushed upward by a thruster(s) means inserted into a pair of holes while the base plate is supported from below and the head substrates is pressed from above. The base plate is bonded to a radiating plate by an adhesive only at the central portion. Thus, there is no difference in level at the joint of the head substrates, and even when the radiating plate expands due to heat, the base plate is not deformed.
    Type: Grant
    Filed: August 4, 1993
    Date of Patent: May 16, 1995
    Assignee: Rohm Company, Limited
    Inventors: Toshio Amano, Yoshinobu Kishimoto, Fumiaki Tagashira, Hisayoshi Fujimoto, Shigeo Ota
  • Patent number: 5337054
    Abstract: A four-terminal network in tandem with a tunnel diode (TD) threshold receiver currently used in radar or communications improves its sensitivity. Previous inventors have shown that the temperature and sensitivity properties of a conventional TD threshold device used for detecting very short duration bursts of microwave energy would be enhanced by appropriately biasing the TD by a current derived from the thermal noise; the current sets the TD operating point. The magnitude of the current is determined by a constant false alarm rate (CFAR) feedback loop. The subject invention recognizes that a TD changes states (i.e., a detection event) when the area under the current vs. time curve or the charge passing through the device exceeds a prescribed number of picocoulombs. To maximize the charge and improve detection, a form of superheterodyne conversion is introduced to convert the oscillatory short pulse microwave signal received by an antenna to a monopolar baseband signal.
    Type: Grant
    Filed: May 18, 1992
    Date of Patent: August 9, 1994
    Assignee: Anro Engineering, Inc.
    Inventors: Gerald F. Ross, Richard M. Mara
  • Patent number: 5311184
    Abstract: Sensitivity time control (STC) data for an airborne weather radar system is provided as a function of aircraft altitude and radar system antenna tilt angle to normalize radar return signals at high as well as low aircraft altitudes. In one form of the invention the STC data is used to adjust the gain of a signal applied to a radar system received by a system antenna and in another form of the invention the STC data is used to establish a desired threshold for said signal.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: May 10, 1994
    Assignee: AlliedSignal Inc.
    Inventor: Daryal Kuntman
  • Patent number: 5298905
    Abstract: A lidar apparatus for detecting an object. The lidar apparatus includes a laser providing a visible light output signal over a first field of view and a photodiode having a second field of view. At least some of the first and second fields of view overlap. The photodiode provides electrical signals in response to received optical signals. A controller is coupled to the laser and to the photodiode. The controller for provides electrical signals to the laser, causing emission of visible light output signals. A time varying threshold generator is coupled to the controller. The time varying threshold generator provides a time varying threshold signal in response to signals from the controller. A threshold detector is coupled to the time varying threshold generator and to the photodiode. The threshold detector compares the time varying threshold signal to the electrical signals to provide signals indicating presence or absence of the object.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: March 29, 1994
    Assignee: Motorola, Inc.
    Inventor: Randy L. Dahl
  • Patent number: 5293325
    Abstract: The signal that controls the gain of a sensitivity timing control (STC) circuit is slimmed with a gain correction signal to compensate for gain variations introduced by items such as variations in the parameters of electronic components. A known test signal is injected into the STC circuit and the resulting output signal is measured. The amplitude of the gain correction signal is determined based on the difference between the desired output signal amplitude and the measured output signal amplitude.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: March 8, 1994
    Assignee: AlliedSignal Inc.
    Inventor: Mark G. Roos
  • Patent number: 5221928
    Abstract: An apparatus comprises a signal input and a sampler and analog-to-digital (A/D) converter coupled to the signal input. The sampler and A/D converter forms a digital pre-look signal from an input signal. The apparatus further comprises a digital memory coupled to the sampler and A/D converter. The digital memory stores sensitivity time control (STC) data and provides specific STC data in response to the digital pre-look signal. The apparatus further comprises a digital-to-analog converter coupled to the digital memory. The digital-to-analog converter converts the specific digital STC data to a first analog STC signal. The apparatus also includes a first comparator coupled to the signal input and to the digital-to-analog converter. The first comparator has an input for receiving the first analog STC signal. The first comparator compares a present input signal to the first analog STC signal to provide a detection signal.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: June 22, 1993
    Assignee: Motorola, Inc.
    Inventor: Randy L. Dahl
  • Patent number: 5196854
    Abstract: The present invention is a radar system that corrects for changes in apparent reflectivity and two-way precipitation attenuation using a correction curve that includes a segment for low rain rates, a segment for high rain rates and, if desired, a transition segment for medium rain rates. The signal to noise ratio is further improved by using a sliding azimuth window during post detection integration processing.
    Type: Grant
    Filed: June 13, 1991
    Date of Patent: March 23, 1993
    Assignee: Westinghouse Electric Corp.
    Inventor: Bruce D. Mathews
  • Patent number: 5115242
    Abstract: Disclosed is an in-furnace slag level measuring apparatus having a microwave radar for measuring a slag level in a convertor or the like. The level of a transmission signal or a reception signal is adjusted in accordance with the level of a detection signal so that the signal level in the microwave radar is adjusted to be constant. Further, the level measurement value and the detection signal are inputted and the level measurement values obtained in a predetermined time are subjected to averaging operation. In the averaging operation, when the detection signal is smaller than a set point, the averaging operation is performed while disregarding the level measurement value at that time.
    Type: Grant
    Filed: March 27, 1991
    Date of Patent: May 19, 1992
    Assignee: NKK Corporation
    Inventors: Akio Nagamune, Kouichi Tezuka, Isamu Komine
  • Patent number: 5050986
    Abstract: An optical ranging system includes optics that create a backscatter signal in response to a transmitted light pulse. The transmitted pulse is reflected from a target to provide range information. The backscatter signal is applied to trigger a threshold detector. The output of the threshold circuit is applied to a delay circuit to provide a receiver switch control signal which renders a receiver switch conductive after the backscatter signal. Accordingly, the receiver switch blanks the backscatter signal and applies the reflected signal to the receiver.
    Type: Grant
    Filed: June 5, 1990
    Date of Patent: September 24, 1991
    Assignee: Motorola, Inc.
    Inventors: Anthony J. Gatto, Randy L. Dahl, John A. Muir
  • Patent number: 4994811
    Abstract: In a sensitivity time control device for an imaging radar system with an automatic gain control attenuator, a sensitivity time control attenuator and an analog-digital converter, output signals of the analog-digital converter are applied, via a device (20) generating an average value and a comparator device, to a control device, which has a ideal on-off relay connected with a device for determining its control parameter, an integrating member, switched downstream, and a device for calculating the operating point of the automatic gain control attenuator device. Furthermore, an n-bit digital analog converter is switched downstream of the control device, by means of the analog output voltage of which the sensitivity time control attenuator is controlled. It is possible, with the aid of the sensitivity time control device, to evaluate continuously the backscatter signal of an imaging radar system in real time, so that it is continuously possible in this way to determine an optimal sensitivity time control curve.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: February 19, 1991
    Assignee: Deutsche Forschungsanstalt fuer Luft - und Raumfahrt e. V.
    Inventor: Joao Moreira
  • Patent number: 4837579
    Abstract: A pulse marine radar system having a threshold generator providing a range dependent threshold waveform which is a function of sea conditions, rain conditions, and radar parameters. Based on the radar settings and inputs from the operator regarding the sea and rain conditions, a processor uses a mathematical model to compute the mean of sea clutter, rain clutter, and receiver noise for each of a plurality of successive range intervals. In response to the mean values, a generator generates a range dependent piecewise linear analog waveform which is subtracted in range sychronism from the receiver video. Next, the video is filtered. For each range interval, the processor also calculates a threshold based on the probability of sea clutter, rain clutter, and receiver noise exceeding the threshold after subtracting the mean. In response to the threshold values, a generator generates a piecewise analog signal which is compared with the output of the filter to digitize the radar video.
    Type: Grant
    Filed: January 27, 1986
    Date of Patent: June 6, 1989
    Assignee: Raytheon Company
    Inventors: William M. Pease, William M. Hall
  • Patent number: 4728953
    Abstract: A radar system includes a variable delay circuit coupled between the transmitter and the receiver switch. A feedback loop including a comparator and an integrator is coupled between the receiver envelope detector and a control terminal for the variable delay circuit. The feedback loop controls the amount of delay of the receiver switch to maximize sensitivity to close range targets.
    Type: Grant
    Filed: October 3, 1986
    Date of Patent: March 1, 1988
    Assignee: Motorola, Inc.
    Inventor: Carl T. Richmond