882 results about "Radar imaging" patented technology

A Catheter Guidance Control and Imaging (CGCI) system whereby a magnetic tip attached to a surgical tool is detected, displayed and influenced positionally so as to allow diagnostic and therapeutic procedures to be performed is described. The tools that can be so equipped include catheters, guidewires, and secondary tools such as lasers and balloons. The magnetic tip performs two functions. First, it allows the position and orientation of the tip to be determined by using a radar system such as, for example, a radar range finder or radar imaging system. Incorporating the radar system allows the CGCI apparatus to detect accurately the position, orientation and rotation of the surgical tool embedded in a patient during surgery. In one embodiment, the image generated by the radar is displayed with the operating room imagery equipment such as, for example, X-ray, Fluoroscopy, Ultrasound, MRI, CAT-Scan, PET-Scan, etc. In one embodiment, the image is synchronized with the aid of fiduciary markers located by a 6-Degrees of Freedom (6-DOF) sensor. The CGCI apparatus combined with the radar and the 6-DOF sensor allows the tool tip to be pulled, pushed, turned, and forcefully held in the desired position by applying an appropriate magnetic field external to the patient's body. A virtual representation of the magnetic tip serves as an operator control. This control possesses a one-to-one positional relationship with the magnetic tip inside the patient's body. Additionally, this control provides tactile feedback to the operator's hands in the appropriate axis or axes if the magnetic tip encounters an obstacle. The output of this control combined with the magnetic tip position and orientation feedback allows a servo system to control the external magnetic field.

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented.

A Catheter Guidance Control and Imaging (CGCI) system whereby a magnetic tip attached to a surgical tool is detected, displayed and influenced positionally so as to allow diagnostic and therapeutic procedures to be performed is described. The tools that can be so equipped include catheters, guidewires, and secondary tools such as lasers and balloons. The magnetic tip performs two functions. First, it allows the position and orientation of the tip to be determined by using a radar system such as, for example, a radar range finder or radar imaging system. Incorporating the radar system allows the CGCI apparatus to detect accurately the position, orientation and rotation of the surgical tool embedded in a patient during surgery. In one embodiment, the image generated by the radar is displayed with the operating room imagery equipment such as, for example, X-ray, Fluoroscopy, Ultrasound, MRI, CAT-Scan, PET-Scan, etc. In one embodiment, the image is synchronized with the aid of fiduciary markers located by a 6-Degrees of Freedom (6-DOF) sensor. The CGCI apparatus combined with the radar and the 6-DOF sensor allows the tool tip to be pulled, pushed, turned, and forcefully held in the desired position by applying an appropriate magnetic field external to the patient's body. A virtual representation of the magnetic tip serves as an operator control. This control possesses a one-to-one positional relationship with the magnetic tip inside the patient's body. Additionally, this control provides tactile feedback to the operator's hands in the appropriate axis or axes if the magnetic tip encounters an obstacle. The output of this control combined with the magnetic tip position and orientation feedback allows a servo system to control the external magnetic field.

Methods and apparatus are presented which reduce the overall cost and increase the imaging capability for medium and long range automotive radar sensing applications through the combination of a high signal-to-noise ratio and wide dynamic range radar waveform and architecture, antenna arrangement, and a low cost packaging and interconnection method. In accordance with aspects of the present invention, one way a high signal-to-noise ratio and wide dynamic range imaging radar with reduced cost can be achieved is through the combination of a pulsed stepped-frequency-continuous-wave waveform and electrically beam-switched radar architecture, utilizing a planar package containing high-frequency integrated circuits as well as integrated high-frequency waveguide coupling ports, coupled to a multi-beam waveguide-fed twist-reflector narrow beam-width antenna. Other methods and apparatus are presented.

Method and apparatus for developing radar scene and target profiles based on Compressive Sensing concept. An outgoing radar waveform is transmitted in the direction of a radar target and the radar reflectivity profile is recovered from the received radar wave sequence using a compressible or sparse representation of the radar reflectivity profile in combination with knowledge of the outgoing wave form. In an exemplary embodiment the outgoing waveform is a pseudo noise sequence or a linear FM waveform.

A 3D imaging ladar system comprises a solid state laser and geiger-mode avalanche photodiodes utilizing a scanning imaging system in conjunction with a user interface to provide 3D spatial object information for vision augmentation for the blind. Depth and located object information is presented acoustically by: 1) generating an audio acoustic field to present depth as amplitude and the audio image as a 2D location. 2) holographic acoustical imaging for a 3D sweep of the acoustic field. 3) a 2D acoustic sweep combined with acoustic frequency information to create a 3D presentation.A system to fuse data derived from a three dimensional imaging ladar system with information from a visible, ultraviolet, or infrared camera systems and acoustically present the information in a four or five dimensional acoustical format utilizing three dimensional acoustic position information, along with frequency, and modulation to represent color, texture, or object recognition information is also provided.

A method of radar-imaging a scene in the far-field of a one-dimensional radar array, comprises providing an array of backscatter data D(fm, x′n) of the scene, these backscatter data being associated to a plurality of positions x′n, n=0 . . . N−1, N>1, that are regularly spaced along an axis of the radar array. The backscatter data for each radar array position x′n are sampled in frequency domain, at different frequencies fm, m=0 . . . M−1, M>1, defined by fm=fc−B / 2+m−Δf, where fc represents the center frequency, B the bandwidth and Δf the frequency step of the sampling. A radar reflectivity image 1(αm′, βn′) is computed in a pseudo-polar coordinate system based upon the formula (2) with formula (3) where j represents the imaginary unit, formula (A) is the baseband frequency, FFT2D denotes the 2D Fast Fourier Transform operator, αm′, m′=0 . . . M−1, and βn′, n′=0 . . . N−1 represent a regular grid in the pseudo-polar coordinate system, and Pmax is chosen >0 depending on a predefined accuracy to be achieved. A corresponding method of radar-imaging a scene in the far-field of a two-dimensional radar array is also proposed.I(αm′,βn′)=∑p=0PmaxIp(αm′,βn′),Formula(2)I(αm′,βn′)=1p![-j2πβn′fc]pFFT2D[D(fm,xn′)(f^m,xn′)p],Formula(3)f^m=-B / 2+m·ΔfFormula(A)

A short range millimeter wave surface imaging radar system. The system includes electronics adapted to produce millimeter wave radiation scanned over a frequency range of a few gigahertz. The scanned millimeter wave radiation is broadcast through a frequency scanned transmit antenna to produce a narrow transmit beam in a first scanned direction (such as the vertical direction) corresponding to the scanned millimeter wave frequencies. The transmit antenna is scanned to transmit beam in a second direction perpendicular to the first scanned direction (such as the horizontal or the azimuthal direction) so as to define a two-dimensional field of view. Reflected millimeter wave radiation is collected in a receive frequency scanned antenna co-located (or approximately co-located) with the transmit antenna and adapted to produce a narrow receive beam approximately co-directed in the same directions as the transmitted beam in approximately the same field of view. Computer processor equipment compares the intensity of the receive millimeter radar signals for a pre-determined set of ranges and known directions of the transmit and receive beams as a function of time to produce a radar image of at least a desired portion of the field of view. In preferred embodiment the invention is mounted on a truck and adapted as a FOD finder system to detect and locate FOD on airport surfaces.

A radar imaging system is provided that directly measures the spatial frequency components of a scene via digital-beam-forming techniques applied along the cross-track dimension. Separate transmit and receive antennas provide increased integration time for the receive function, thus improving the signal-to-noise ratio. A segmented receive antenna is employed and processed as a series of interferometers sensitive to spatial frequency components of the scene corresponding to the separation between pairs of antenna elements. Range gating is used in the along-track dimension to divide the return from an illuminated swath into multiple range bins that may be processed independently. The system provides an improved signal-to-noise ratio and lends significant flexibility to the image formation process, improving the quality of the radar imaging. An embodiment having multiple transmit antennas is also provided that enables the generation of three-dimensional stereoscopic radar images.

A system for identifying an individual, including an imaging radar for receiving radar data pertaining to at least a portion of a skeleton of at least one individual, an imaging module for generating at least one skeletal image of the at least one individual based on the radar data, at least one database including a plurality of skeletal data pertaining to a plurality of individuals, an identification module for comparing the at least one skeletal image with the plurality of skeletal data to determine a match.

A method of detecting and tracking objects using multiple radar sensors. Objects relative to a host vehicle are detected from radar data generated by a sensing device. The radar data includes Doppler measurement data. Clusters are formed, by a processor, as a function of the radar data. Each cluster represents a respective object. Each respective object is classified, by the processor, as stationary or non-stationary based on the Doppler measurement data of each object and a vehicle speed of the host vehicle. Target tracking is applied, by the processor, on an object using Doppler measurement data over time in response to the object classified as a non-stationary object; otherwise, updating an occupancy grid in response to classifying the object as a stationary object.

A short range millimeter wave imaging radar system. The system includes electronics adapted to produce millimeter wave radiation scanned over a frequency range of a few gigahertz. The scanned millimeter wave radiation is broadcast through a frequency scanned transmit antenna to produce a narrow transmit beam in a first scanned direction (such as the vertical direction) corresponding to the scanned millimeter wave frequencies. The transmit antenna is scanned to transmit beam in a second direction perpendicular to the first scanned direction (such as the horizontal or the azimuthal direction) so as to define a two-dimensional field of view. Reflected millimeter wave radiation is collected in a receive frequency scanned antenna co-located (or approximately co-located) with the transmit antenna and adapted to produce a narrow receive beam approximately co-directed in the same directions as the transmitted beam in approximately the same field of view. Computer processor equipment compares the intensity of the receive millimeter radar signals for a pre-determined set of ranges and known directions of the transmit and receive beams as a function of time to produce a radar image of at least a desired portion of the field of view. In preferred embodiment the invention is mounted on a truck and adapted as a FOD finder system to detect and locate FOD on airport surfaces.

A tissue-sensing adaptive radar method of detecting tumours in breast tissue uses microwave backscattering to detect tumours which have different electrical properties than healthy breast tissue. The method includes steps for reducing skin reflections and for constructing a three-dimensional image using synthetic focusing which shows the presence or absence of microwave reflecting tissues.

An earth penetrating apparatus includes a cutting tool and a sensor housing. A radar unit, rate sensor unit, processor, and transmitter are provided in the sensor housing. An antenna arrangement is coupled to the radar unit and configured for transmitting and receiving electromagnetic signals in a relatively forward and / or lateral looking direction relative to a distal end of the cutting tool. The rate sensor unit may include one or both of a gyroscope and an accelerometer. The processor receives radar data from the radar unit indicative of subsurface strata and obstacles respectively located generally forward and / or lateral of the cutting tool, and receives displacement data from the rate sensor unit indicative of one or both of longitudinal and rotational displacement of the cutting tool. The transmitter is configured for transmitting one or both of the radar data and the displacement data to an aboveground location.

The invention provides a laser imaging radar device and a distance measurement method thereof. The laser imaging radar device and the distance measurement method thereof aims at the problem that an existing distance range gate laser imaging radar is low in distance resolution. The laser imaging radar device comprises a laser device, a laser modulation unit, an optical antenna unit, a detecting unit, a data processing unit and an image processing unit, wherein the detecting unit is composed of a counter, a gate controller and an array detector, and the data processing unit is composed of an accumulator and a correlator. According to the distance measurement method, an information loading process is carried out on laser signals with constant amplitude by using a phase code pulse amplitude modulation mode. The laser imaging radar device and the distance measurement method thereof have the advantages that the equipment and the method combine the advantages of long detecting distances of the distance ranging gate layer imaging radar and the advantage of high distance measurement resolution of the pulse phase coding mode, and meanwhile the detect of low distance measurement resolution of the distance ranging gate layer imaging radar and the detect of low imaging speed of the pulse phase coding mode are avoided.

A time-reversal imaging radar system for acquiring an image of a remote target includes an antenna array having a plurality of spaced-apart antennas, and a transceiver coupled to the antenna array for alternately transmitting a radar signal via the antenna array toward the target and for receiving target-reflected radar signals. The transceiver includes means for multiple-pass time-reversing the transmitted and received radar signals whereby coherent beam focusing is realized at both the target and at the receiver to thereby enhance the resolution of the acquired target image.

A radar imaging apparatus includes: (i) a delay code generation unit which repeats, for M scan periods, scan processing of generating, using a transmission code, N delay codes in a scan period for scanning N range gates having mutually different distances from the radar imaging apparatus; (ii) a signal storage unit which stores, in association with a range gate and a scan period, a baseband signal; (iii) a memory control unit which repeatedly writes, in the signal storage unit, for the M scan periods, N demodulated signals corresponding to a single scan period, and reads out a group of M demodulated signals corresponding to mutually different scan periods; (iv) a Doppler frequency discrimination unit which performs frequency analysis on demodulated signals having the same range gate; and (v) a direction of arrival calculation unit which estimates a direction of a target.

A radar imaging system for capturing an image of an object within an area of interest through at least one visual impairment. The radar imaging system comprises at least one radar array. The radar array includes a plurality of transmitter elements and a plurality of receiver elements for receiving a plurality of coded return signals from an object through the at least one visual impairment. The system further comprises at least one processor coupled to the transmitter and receiver elements, which is adapted to transmit a plurality of differently coded signals toward the object and the at least one visual impairment; decode the plurality of coded return signals received by each of the receiver elements; extract from the decoded return signals a multiplicity of captured signals for each transmitter to receiver path; focus the multiplicity of signals on all points of interest within the area of interest by aligning the multiplicity of captured signals to be co-incident from a particular point within the area of interest; and sum the aligned signals to produce an image of the object. A method for capturing an image of an object in an area of interest through at least one visual impairment is also provided.

An earth penetrating apparatus includes a cutting tool and a sensor housing. A radar unit, rate sensor unit, processor, and transmitter are provided in the sensor housing. An antenna arrangement is coupled to the radar unit and configured for transmitting and receiving electromagnetic signals in a relatively forward and / or lateral looking direction relative to a distal end of the cutting tool. The rate sensor unit may include one or both of a gyroscope and an accelerometer. The processor receives radar data from the radar unit indicative of subsurface strata and obstacles respectively located generally forward and / or lateral of the cutting tool, and receives displacement data from the rate sensor unit indicative of one or both of longitudinal and rotational displacement of the cutting tool. The transmitter is configured for transmitting one or both of the radar data and the displacement data to an aboveground location.

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

A method of detecting and tracking objects using multiple radar sensors. Objects relative to a host vehicle are detected from radar data generated by a sensing device. The radar data includes Doppler measurement data. Clusters are formed, by a processor, as a function of the radar data. Each cluster represents a respective object. Each respective object is classified, by the processor, as stationary or non-stationary based on the Doppler measurement data of each object and a vehicle speed of the host vehicle. Target tracking is applied, by the processor, on an object using Doppler measurement data over time in response to the object classified as a non-stationary object; otherwise, updating an occupancy grid in response to classifying the object as a stationary object.

The invention discloses a scanning three-dimensional imaging laser radar based on a linear array APD detector and an imaging method. The laser radar shapes the circular Gaussian laser beams into stripe laser to be transmitted, the linear array APD detector receives the laser echo, and the receiving field of view of the linear array APD detector coincides with the far-field facula of the laser. The range data are finally obtained after the signals output by the detector are amplified and processed. The laser radar completes measurement of the whole field of view via a two-dimensional scanning mechanism. The invention greatly improves the detection efficiency without increasing the repetition frequency of the laser and can meet the application requirement for demanding imaging time.

The invention belongs to the technical field of radar target imaging and monitoring, in particular relates to a compound electromagnetic scattering value simulation method of electrically large complex object and rough surface background. The method comprises the following steps of: synthesizing a two-dimensional arc aperture by using a frequency stepping radar in a down spotlight mode, simulating (observing) a electromagnetic scattered radar echo value of a electrically large complex three-dimensional target through the frequency stepping radar to obtain a three-dimensional back scattering matrix containing amplitude and phase; obtaining a uniform re-sampling data in an X-Y-Z coordinate system through a three-dimensional interpolation in a wave number domain; performing the three-dimensional rapid Fourier conversion on the re-sampling data to obtain a three-dimensional focus image to further reconstruct a geometric feature of the three-dimensional complex target. A numerical value execution result proves that the compound electromagnetic scattering value simulation method has feasible, accurate and high-efficient performance in the simulation of the three-dimensional complex target scattering monitoring, radar imaging and geometric feature reconstructing on a rough surface background.

An imaging processing system and method. In accordance with the invention, the illustrative method includes the steps of providing a transfer function between scene excitations and voltage returns based on geometry, beam pattern and / or scan rate; ascertaining a set of scene excitations that minimize a penalty function of the transfer function; and ascertaining a set of scene intensities based on the scene excitations, and a set of optimal weights for the penalty function based on the scene reflectivities. The inventive method provides significantly enhanced image sharpening. In the illustrative embodiment, the inventive method uses an iterative convergence technique which minimizes a penalty function of the sum of square errors between the scene excitations corrupted by the radar system (i.e. the antenna pattern and processing) and the radar voltage returns. The innovation significantly enhances radar imagery by iteratively deriving a best scene solution, which reduces corruption introduced by the radar system. The novel technique for enhanced discrimination by the radar imagery is an iterative technique, which models the true scene signal corruption and derives a solution for the scene intensities, which minimizes the errors in the derived image. The novel technique finds the scene scatterer powers, which best match the original image pixel powers. The effect of the antenna pattern is taken into consideration when computing the derived image, which is matched against the original image. The constraint is implemented iteratively by adding a weighted sum of scene powers to the penalty function. The weights are adjusted at each iteration.

A radar imaging system is provided that directly measures the spatial frequency components of a scene via digital-beam-forming techniques applied along the cross-track dimension. Separate transmit and receive antennas provide increased integration time for the receive function, thus improving the signal-to-noise ratio. A segmented receive antenna is employed and processed as a series of interferometers sensitive to spatial frequency components of the scene corresponding to the separation between pairs of antenna elements. Range gating is used in the along-track dimension to divide the return from an illuminated swath into multiple range bins that may be processed independently. The system provides an improved signal-to-noise ratio and lends significant flexibility to the image formation process, improving the quality of the radar imaging. An embodiment having multiple transmit antennas is also provided that enables the generation of three-dimensional stereoscopic radar images.

The invention discloses a method for obtaining mining area earth surface three-dimensional deformation fields through a single interferometric synthetic aperture radar (InSAR) interference pair. The method includes that a mining field radar sight deformation field is obtained through an InSAR technology, pixels with coherence which is lower than an unwrapping threshold value in the sight deformation field is subjected to spatial interpolation to obtain a spatial continuous deformation field, main effective radius of each pixel is calculated through mining area working face distribution and main effective angles, after mining area horizontal shifting coefficients are obtained, the mining area earth surface horizontal shifting is converted to an expression of a sinking value, an equation set is formed according to the radar imaging principle, the equation set is solved to obtain a solution of the earth surface sinking value, according to the sinking value, tilting values of east, west, south and north directions are calculated, and the deformation fields of the east, west, south and north directions are calculated according to a proportional relation among the tilting values of the east, west, south and north directions and the horizontal shifting. The method has the advantages that the restrictions that when the three-dimensional deformation field is solved by the aid of the InSAR, the requirements for data are strict, the monitoring cost is high and the like are broken, and the application space of the InSAR technology in the mining area is greatly widened.