230 results about "Wideband radar" patented technology

The invention discloses a multi-life monitoring system based on FMCW (frequency modulated continuous wave) wideband radar. The multi-life monitoring system comprises a transmitting unit, a receiving unit, a signal processing unit and a wireless signal transmitting unit; an FMCW signal is transmitted from the FMCW wideband radar to no less than one human object by virtue of the transmitting unit; a reflected echo signal is received by virtue of the receiving unit; the echo signal, which carries vital sign signals, is processed by virtue of the signal processing unit; the vital sign signals are demodulated and separated from the echo signal; and the vital sign signals are transmitted to a computer terminal by virtue of the wireless signal transmitting unit, so that respiration and heartbeat signals of detected persons are monitored under the condition of avoiding contact with the bodies of the detected persons. With the implementation of the multi-life monitoring system disclosed by the invention, under the circumstance of avoiding the contact of any electrodes and sensors with patients, the respiration and heart rates of the plurality of patients can be simultaneously monitored by a long time at a relatively long distance, so that the detected persons can feel more easily and comfortably; the multi-life monitoring system can be widely applied to clinical dynamic monitoring and sleep quality monitoring of patients with severe burn and the like; and meanwhile, the multi-life monitoring system can be also applied to researches in the field of psychology.

The present invention belongs to the technical field of radar target detection and discloses a range-extended target adaptive detection method under inverse Gaussian texture complex Gaussian clutter for the target detection under a wideband radar system. The method comprises a step of establishing the binary hypothesis model of radar target detection, a step of using a spherically invariant vector process model to construct an inverse Gaussian texture complex Gaussian clutter signal, a step of using a generalized likelihood ratio to obtain a range-extended target adaptive detector under the inverse Gaussian texture complex Gaussian clutter, a step of determining the detection threshold of the adaptive detector, a step of obtaining radar echo data and determining the detection statistic amount of the radar echo data according to the adaptive detector, and a step of judging whether the radar echo data has a range-extended target according to the detection statistic amount and the detection threshold, and if the detection statistic amount is larger than the detection threshold, determining that the radar echo data has the range-extended target, otherwise, determining that the radar echo data has no range-extended target.

The invention provides a method for detecting a broadband radar on the basis of continuous high-resolution target distance image-correction correlation matrix, and the method comprises the following steps: (1) standard deviation estimation is carried out to the noise of distance images that contain noise; (2) based on the standard deviation, a set of non-linear contraction mapping is established, and then the distance images that contain noise are refined according to the contraction mapping, thus obtaining refined multi-pulse distance images; (3) based on the multi-pulse distance images, cross correlation coefficient between every two refined distance images is calculated, thus obtaining a corrected cross correlation coefficient matrix; (4) the cross correlation coefficient matrixes are accumulated to establish the detecting statistic value, and the detecting threshold of current noise variance is set; (5) the detecting statistic value and the detecting threshold are compared to judge whether the target exists. The method has the advantages of cross distance unit detection and multi-pulse accumulation and is used for detecting a non-cooperative target under unknown prior information condition.

The spurious-free dynamic range of a wideband radar system is increased by apportioning de-ramp processing across analog and digital processing domains. A chirp rate offset is applied between the received waveform and the reference waveform that is used for downconversion to the intermediate frequency (IF) range. The chirp rate offset results in a residual chirp in the IF signal prior to digitization. After digitization, the residual IF chirp is removed with digital signal processing.

The invention discloses a radar based respiration and heartbeat signal detection method and system. The method comprises the steps of A, judging whether a target exists based on a transmitting signaland a receiving signal; and B, performing the following processing on a mixed vital sign signal of the target: B1, performing high-pass filtering and FFT on the mixed vital sign signal to obtain firstfrequency spectrum data; B2, if the frequency corresponding to a maximum amplitude value point is within a respiratory frequency range and the maximum amplitude value point exists at a Q frequency doubling position and/or near the Q frequency doubling position of the frequency, taking the frequency as a respiratory dominant frequency; B3, decomposing the mixed vital sign signal of the target based on empirical wavelet transform; and B4, if the maximum value frequency of a third component or a fourth component is within a preset heartbeat frequency range, taking the maximum value frequency asa heartbeat dominant frequency. Based on the empirical wavelet transform, respiration and heartbeat signals are adaptively separated and the frequencies of the respiration and heartbeat signals are accurately extracted, and the respiration and heartbeat frequencies of multiple persons can be simultaneously extracted and separated for a broadband/ultra-wideband radar.

Disclosed in the invention is a full-coherent X-waveband broadband radar object simulator comprising a radar signal generator, an up conversion assembly, an X-waveband fiber delay device, a digitally controlled attenuator and a frequency synthesizer. The output terminal of the frequency synthesizer is connected with the input terminal of the radar signal generator and the input terminal of the up conversion assembly; the output terminal of the radar signal generator is connected with the input terminal of the up conversion assembly, the input terminal of the X-waveband fiber delay device, and the input terminal of the digitally controlled attenuator; the output terminal of the up conversion assembly is connected with the input terminal of the X-waveband fiber delay device; and the output terminal of the X-waveband fiber delay device is connected with the input terminal of the digitally controlled attenuator. According to the invention, with cooperation of the existing radar signal generator, various intermediate-frequency signals needed by the modern radar system can be generated and a full-coherent large-broadband radar object echo radio-frequency signal with high simulation quality and excellent fidelity can be simulated. And the simulator can be applied to debugging and performance detection of a radar receiving sub machine and a signal processing sub machine.

The invention refers to a method and device for wideband radar, the method comprising: generating a wideband signal (1, 6) with a bandwidth B; copying the wideband signal (1, 6); transmitting the wideband signal (6′); receiving a returned echo signal (11) from the transmitted signal (6′); dividing the copied signal into a number, N_f, of subsequent frequency bands b; manipulating the copied and divided signal into an anticipated signal (10) by adding a number N_d of anticipated delays and a number of N_D Doppler stretches to the copied and divided signal for each N_f subsequent frequency band b; dividing the received signal (17) into a number, N_f, of subsequent frequency bands b; correlating corresponding frequency bands in the divided received signal (17) and the anticipated signal (10) giving N_dN_D correlated signals (19) for determining range (R) to a target and velocity (v) of the target.

The invention provides a wideband radar cross-section reduction slot array antenna based on hybrid super-surface. The antenna comprises a lower dielectric plate (1) and an upper dielectric plate (2),wherein second and third dielectric plates (3, 4) are sequentially and closely attached above the upper dielectric plate, and fourth, fifth and sixth dielectric plates (5, 6, 7) are sequentially placed at different intervals above the third dielectric plate; the upper surfaces of the second and third dielectric plates are respectively printed with L-shaped metal patch units (31, 41) in checkerboard type arrangement; the lower surface of the fourth dielectric plate is respectively printed with an impedance structure (51) and a metal patch unit (52) in checkerboard type arrangement; the lower surface of the fifth dielectric plate (6) is printed with a plurality of strip metal patches (61); and the upper and lower surfaces of the sixth dielectric panel (7) are respectively printed with the metal patch unit (52) and the impedance structure (51) in checkerboard type arrangement. The wideband radar cross-section reduction slot array antenna has good scattering characteristics and realizes effective reduction of the cross-band single-station and double-station radar cross sections in the slot array antenna.

The invention discloses a broadband radar target complex echo de-noising method based on sparseness constraints. The method comprises the steps of (1) obtaining a target complex distance image, (2) determining a coefficient vector and a penalty factor, (3) constructing a de-noising performance evaluation function, (4) updating the coefficient vector, (5) judging whether a relative error is larger than an error threshold or not, (6) restoring the complex distance image. According to the broadband radar target complex echo de-noising method based on the sparseness constraints, by the adoption of the super-resolution Fourier base, the signal to noise ratio of broadband radar target complex echoes can be better improved, and the broadband radar target complex echo de-noising method can be used for conducting noise suppression on the radar echoes of moving objects such as airplanes and automobiles under the noise background.

The invention provides an ultra-wideband radar signal generating and synthesizing device, which comprises a bus control communication module, an ultra-wideband waveform generating module and a simulated correction signal generating module, wherein the bus control communication module receives a control instruction and generates waveform control signals; the ultra-wideband waveform generating module comprises an FPGA and a DAC, the FPGA generates multichannel parallel digital signals according to the received waveform control signals and clock signals, and the DAC receives the parallel digital signals, carries out parallel-serial conversion to synthesize high-speed DDS data, and carries out analog-digital conversion to output radar signals; and the simulated correction signal generating module receives the ultra-wideband radar signals and outputs simulated correction signals of a sum channel and two difference channels. The generated ultra-wideband signals are synthesized by adopting a digital mode, and a hardware circuit is simple in structure.

In some aspects, the disclosure is directed methods and systems for establishing a wideband radar system for imaging. A receiver of a radar imaging system may receive a set of phase measurements for each of a plurality of frequency bands, each of the plurality of frequency bands established by up-converting or down-converting a base frequency band. A phase adjuster of the radar imaging system may identify, from each region of overlap between consecutive frequency bands of the plurality of frequency bands, a phase difference between corresponding sets of the phase measurements. The phase adjuster may adjust one or more sets of the phase measurements based on the identified phase differences to generate an image across the plurality of frequency bands.

The invention discloses an optical transparent ultra-wideband radar and infrared double-stealth structure, and relates to the technical field of multi-spectrum stealth, and the stealth structure mainly comprises a low-emissivity infrared stealth layer and an ultra-wideband radar wave-absorbing layer. In order to realize high transmittance of visible light, an optical transparent material transparent conductive film and a transparent dielectric are selected in the overall structural design; the radar wave-absorbing layer adopts a conductive film-medium-conductive film sandwich type wave-absorbing structure; the transparent conductive film is etched into a frequency selective surface by adopting a laser etching process to finish the preparation of the radar and infrared compatible stealth material; the optical transparent ultra-wideband radar and infrared compatible stealth material has high designability, the contradictory problem of optical transparency, radar stealth and infrared stealth can be well solved from the perspective of structural design by adopting a metamaterial technology, and the optical transparent ultra-wideband radar and infrared compatible stealth material has good ultra-wideband radar wave absorption performance, low infrared emissivity and optical transparency.

The invention relates to a target feature extraction method for one-dimensional imaging of a target by using a broadband radar. The target feature extraction method is used for solving the problems that the target features of a sea target are easily unstable under the influence of sea clutters when the sea target is subjected to broadband imaging, and the like, caused by the fact that the current broadband radar one-dimensional imaging method for the target mainly acquires the electromagnetic scattering characteristics of the external shape of the target. In order to obtain more stable identification results, a one-dimensional high-resolution distance feature extraction algorithm is provided by the technical scheme adopted by the invention, so that the accurate extraction of one-dimensional image features is realized, the discrimination and identification of one-dimensional broadband images of the sea target are realized. The target feature extraction method comprises the following specific steps of: judging the correctness of one-dimensional imaging data of the target so as to eliminate singular values which affect data computed results; accurately judging imaging starting and ending positions of the target so as to provide a basis for the judgment of target size and a support for back-end processing; and carrying out extraction and computation on numerical features of the target. The target feature extraction method provided by the invention has the advantages that the difficult problem in extraction of identification features of the target is solved, and a technical support for identification of broadband images of the target is provided.

The invention discloses a broadband radar three-dimensional interference measurement cone target fretting parameter estimation method. The method comprises steps that a transmitting-receiving integrated antenna A, a receiving antenna B, and a receiving antenna C are determined, and an interference phase difference between the transmitting-receiving integrated antenna A and the receiving antenna Bon a kth scattering center and the interference phase difference between the transmitting-receiving integrated antenna A and the receiving antenna C on the kth scattering center are acquired: k is anyone of a set number of scattering centers, which are disposed on a cone target; the reconstruction x axis coordinate curve of the kth scattering center after smoothing processing, and the reconstruction y axis coordinate curve of the kth scattering center after the smoothing processing, and the reconstruction z axis coordinate curve of the kth scattering center after the smoothing processing aredetermined, and then after the precession frequency estimated value <^>f<c> of the cone target, the angle of precession estimated value <^>Theta of the cone target, the half cone angle estimated value<^>Eta of the cone target, the height estimated value <^>H of the cone target, and the bottom surface radius estimated value <^>r of the cone target are acquired, a broadband radar three-dimensionalinterference measurement cone target fretting parameter estimated result is acquired.

The invention provides an ultra-wideband radar human body target attitude visualization enhancement method and aims to solve problems that a traditional ultra-wideband radar human body imaging resultis relatively abstract, low in resolution and difficult to visually understand. The method comprises steps of firstly, carrying out three-dimensional imaging of a detection scene; detecting the position of a human body target, and obtaining the imaging result of the human body target; performing feature extraction of a radar image corresponding to the human body target by using a resnet network; converting a feature matrix into probability distribution of human skeleton points by using a headnet network; and lastly, extracting position coordinates of the human skeleton points by using a soft-argmax function, and connecting and displaying the coordinate points to obtain a visual three-dimensional attitude graph of the human target. The method is advantaged in that the three-dimensional human body posture is estimated from an abstract three-dimensional radar image by means of a deep neural network tool, visualization performance of ultra-wideband radar human body target detection is enhanced, and a user is assisted in interpreting the posture of the human body target with higher precision.

The invention provides an ultra-wideband radar single-channel digital beam forming method based on a space-time coding array, and aims to reduce the sidelobe level of the distance dimension and the angle dimension of a DBF output signal and improve the precision and the angle resolution of a beam pointing angle. The method comprises the following implementation steps of constructing a space-time coding array; obtaining a digital baseband signal based on the space-time coding array; performing pulse compression on the digital baseband signal; performing Fourier transform on the signal obtainedby pulse compression; performing Keystone transform on the frequency domain signal; setting frequency domain equivalent DBF algorithm parameters; and obtaining an ultra-wideband radar digital beam forming result based on a frequency domain equivalent DBF algorithm. According to the ultra-wideband radar single-channel digital beam forming method provided by the invention, the space-time coding array is constructed, and spatial coding is carried out on the array spatial domain signal, so that the sidelobe level of the distance dimension and the angle dimension of the DBF output signal is effectively reduced, the ultra-wideband radar digital beam forming result is obtained based on frequency domain equivalence, and the precision and the angle resolution of the beam pointing angle are effectively improved.

The invention discloses a wideband radar aperture transit effect adaptive compensation method. By means of the method, the aperture transit time difference can be adaptively compensated. The method takes a Chirp signal as a transmitting signal, and specifically comprises the following steps of receiving a target echo signal by a phased array radar; according to the transmitting signal, generatinga dechirped reference signal; performing frequency mixing and low-pass filtering on the target echo signal and the reference signal, wherein the processed echo signal adopts a wideband scattering point model, namely, the processed echo signal is formed by superposing echoes of target scattering points; selecting a reference subarray in the phased array radar, performing cross correlation operationon dechirped data of paths of other subarrays except the reference subarray and dechirped data of the reference subarray, and estimating the aperture transit effect compensation values of the paths of other subarrays according to a cross correlation operation result; and compensating the aperture transit time by adopting the calculated aperture transit effect compensation values of the paths of other subarrays.

A precession cone target parameter extraction method under a foresight condition comprises the following steps: (1) constructing a radar observation model, obtaining scattering point echoes of a precession cone target, multiplying an echo signal by a phase compensation function Scom (tm), and eliminating a micro-Doppler component brought by rotation of an antenna; applying an EMD method to the echo signal after phase compensation to obtain a plurality of intrinsic mode functions (IMFs), extracting each IMF frequency, and realizing effective estimation of a target coning frequency; (2) carrying out time-frequency analysis on the echo after phase compensation to obtain a micro-Doppler curve, and carrying out skeleton extraction on the curve to improve the estimation precision; a broadband radar is arranged at the original point, a high-resolution one-dimensional distance sequence of scattering points is obtained, and geometric parameters and motion parameters of the precession cone target are jointly estimated by combining the coning frequency, the high-resolution one-dimensional distance image and the peak value of the micro-Doppler curve obtained in the above steps. The method can overcome the defect that a single-base radar cannot effectively extract the target micro-Doppler parameters under the condition that the micro-motion plane is perpendicular to the radar sight line direction.

The present invention relates to a wide-band radar detector with an electronic compass integrated therein. The radar detecting unit includes a horn antenna, a signal processing unit for detecting signals received by the horn antenna, a laser module for receiving laser signals, a central processing unit for controlling the detection of the signals, a visual display means for visually displaying the detected signals, and a voice producing means for outputting the detected signals to a speaker. The electronic compass includes a magneto-inductive sensor for sensing the earth's magnetic field and a sensor controlling unit. The sensor controlling unit then transmits the values sensed by the magneto-inductive sensor to the central processing unit.