26 results about "Pulsed doppler" patented technology

The invention relates to a method for determining at least a flow velocity or a fluid volume flow (5) of a fluid flowing through an implanted vascular support system (1), comprising the following steps: a) carrying out a pulsed Doppler measurement by means of an ultrasonic sensor (2) of the support system (1), b) evaluating a measurement result from step a), which has a possible ambiguity, c) providing at least one operating parameter of a flow machine (3) of the support system (1), d) determining at least the flow velocity or the fluid volume flow (5) using the measurement result evaluated in step b), wherein the possible ambiguity of the measurement result is corrected using the operating parameter.

The invention relates to a method for determining a flow rate of a fluid flowing through an implanted vascular assist system, said method comprising the following steps: a) carrying out a first pulsed Doppler measurement at a first pulse repetition rate by means of an ultrasonic sensor of the assist system; b) carrying out a second pulsed Doppler measurement at a second pulse repetition rate by means of the ultrasonic sensor of the assist system, wherein the second pulse repetition rate differs from the first pulse repetition rate; c) determining the flow rate using measurement results of the first pulsed Doppler measurement and the second pulsed Doppler measurement.

The invention discloses a pulse Doppler radar target detection method and system based on a background contrast attention mechanism, and relates to the field of radar target detection. The method comprises the following steps: preprocessing data to generate a distance Doppler image; constructing a neural network based on a background contrast attention mechanism; the neural network is trained, and the trained neural network is obtained; and obtaining a detection result of a pulse Doppler image to be detected by using the trained neural network. Based on a background contrast attention mechanism, the method focuses on learning clutter distribution characteristics of a background in a distance Doppler map and inhibiting background features from a feature level, thereby improving the significance of target features. A multi-scale background learner module based on a random mask and an attention mechanism module based on background contrast are designed in a targeted manner, and JS divergence is introduced into a loss function, so that background interference can be better suppressed from a feature level, and the detection performance in a low signal-to-clutter ratio scene is improved.

The invention relates to a method for determining at least a flow velocity or a fluid volume flow of a fluid flowing through an implanted vascular support system, comprising the following steps: a) carrying out a pulsed Doppler measurement by means of an ultrasonic sensor of the support system, b) evaluating a measurement result from step a), which has a possible ambiguity, c) providing at least one operating parameter of a flow machine of the support system, d) determining at least the flow velocity or the fluid volume flow using the measurement result evaluated in step b), wherein the possible ambiguity of the measurement result is corrected using the operating parameter.

The application discloses a dual-channel parallel detection airborne phased array radar ground moving target extraction method, comprising the following steps: acquiring coherent pulse train data of an airborne phased array radar; forming sum-difference beam data according to preset sum-difference beam weighting coefficients; constructing a pulse compression matching function to perform pulse compression on the sum-difference beam data; performing platform motion compensation and pulse Doppler processing on the pulse compressed sum-difference beam data; performing high-speed channel determination according to amplitude statistical results of each Doppler unit of the sum beam, and performing CFAR detection; performing low-speed channel determination according to the amplitude statistical results of each Doppler unit of the sum beam, processing low-speed channel data by using sum-difference 3DT-STAP algorithm, and performing CFAR detection and amplitude normalization processing on the processed data; merging the CFAR detection results of the high-speed channel data and the CFAR detection and amplitude normalization processing results of the low-speed channel data, and extracting a point track.

The present invention discloses a method for estimating the target Doppler frequency based on T-IAA. The specific steps thereof include: uniformly gridding the Doppler frequency space to generate a pilot vector set; determining the range of the target Doppler frequency to be estimated; setting a transformation matrix; performing transformation processing on the received signal and the pilot vector set; estimating the target Doppler frequency by using the iterative adaptive algorithm; and statistically calculating the resolution probability of the target Doppler frequency and the root mean square error of the estimated value. Based on the received signal of the pulsed Doppler radar, the present invention forms T-IAA by setting a transformation matrix and then estimating the target Doppler frequency in the Doppler domain by using the iterative adaptive algorithm. The method of the present invention ensures achieving the super-resolution of IAA while reducing the dimension of the inverse matrix required in IAA, reducing the computational amount of the algorithm and the system complexity, and facilitating engineering implementation.

The invention relates to a brain small vessel blood flow monitoring method and system based on ultrasonic imaging, and the method comprises the steps: setting pulse Doppler ultrasonic imaging devices at different positions, and carrying out the color pulse Doppler imaging of the artery and vein in a brain small vessel through the pulse Doppler ultrasonic imaging devices, arranging according to spatial positions corresponding to different positions to obtain three-dimensional color pulse Doppler imaging; in the process of color pulse Doppler imaging, comparing and analyzing a current frame of color pulse Doppler image and a previous frame of color pulse Doppler image to obtain an analysis result for optimizing a subsequent color pulse Doppler image; blood flow power information is extracted from the three-dimensional color pulse Doppler imaging, and the blood flow change condition of the small cerebral vessels is obtained based on the blood flow power information. The brain small vessel blood flow monitoring system can realize real-time and dynamic monitoring of brain small vessel blood flow, has high clinical application value, and provides a new technical means for prevention and treatment work of brain small vessel diseases.

The invention relates to the related technical field of signal processing, in particular to a signal processing method and system for a radar life detector, and the method comprises the steps: collecting a radar detection signal, and configuring a parameter judgment reference; evaluating the analysis feasibility of the pulse Doppler radar signal, and determining a local detection sub-region under the echo signal intensity distribution mark; and adjusting the sampling frequency and the detection coverage of the signal processing unit, and generating a detection report. The technical problems that signals are processed at a fixed sampling frequency and a detection range, blind analysis is still performed when the effective analysis probability of the signals is low, local signals are easily ignored under a complex terrain, and the detection reliability is difficult to guarantee are solved, an effective analysis probability evaluation mechanism is introduced, only high-probability analyzable signals are deeply processed, local detection sub-regions are locked, and the detection reliability is ensured. The technical effects of synchronously adjusting the sampling frequency and the detection coverage range, eliminating a detection blind area under a complex terrain, performing registration correction on radar scanning surface data and discrete point data, and ensuring the detection reliability are achieved.

The invention belongs to the technical field of radar height measurement, and particularly discloses an inter-pulse phase modulation radar height measurement method based on range ambiguity. The method comprises the following steps: a transmitting branch of a pulse Doppler radar altimeter transmits a pulse signal; a receiving branch of the pulse Doppler radar altimeter receives the echo signal; obtaining an echo signal after the range gate is gated, and determining a demodulation code corresponding to the range gate; and carrying out decoding identification on the echo signal of the target distance received at the distance door according to the demodulation code. According to the scheme, the technical problem of fuzzy ranging of the pulse Doppler system radar altimeter is solved.

A complex environment echo recognition method based on an invariant scattering convolutional network and LSTM, comprising the following steps: S1, establishing geometric models and electromagnetic parameter models of several typical environments; S2, based on the geometric models and electromagnetic parameter models in S1, simulating echo signals under a pulsed Doppler radar system; S3, establishing an invariant scattering convolutional network to extract characteristic data of the echo signals in S2; S4, based on the characteristic data of the echo signals in S3, establishing a training data set and a test data set; S5, establishing an LSTM network model, and inputting the training data set in S4 to train the LSTM network model; S6, using the trained LSTM model in S5 to perform classification tests on the test data set in S3. The present invention can not only reduce the complexity of signals, but also obtain high-order semantic information of signals.

The invention discloses an ultrasonic measurement method and an ultrasonic imaging device, and the method comprises the steps: obtaining a carotid artery ultrasonic image of a target object, and carrying out the image recognition, thereby obtaining a recognition result; displaying the measurement items in all the imaging modes corresponding to the recognition result on the same display interface; when any measurement item is selected, measurement of the measurement item is executed in the imaging mode corresponding to the selected measurement item, and a measurement result is displayed; wherein the identification result comprises a section type of a blood vessel section corresponding to a carotid artery blood vessel region in the carotid artery ultrasonic image; when the image is a cross section, displaying a measurement item in a two-dimensional gray-scale imaging mode; when the section is a longitudinal section, identifying a corresponding section type; displaying a measurement item in a two-dimensional gray-scale imaging mode when the carotid artery is the globe part of the carotid artery; and when the arteries are common carotid arteries, internal carotid arteries or external carotid arteries, respective measurement items in a two-dimensional gray-scale imaging mode, a color Doppler imaging mode and a pulse Doppler imaging mode are displayed. The method can reduce user operations.

The present invention discloses a spatio-temporal blind synchronization method for underwater acoustic waves and airborne radar waves, which relates to the field of radar detection. The method includes: a pulsed Doppler radar generates multiple detection pulses in the air to conduct a cruising search of the sea surface; the radar uses the PRF search of multiple phase channels to sample the echo of the water surface micro-motion signal; the signal processor of the radar processes the sampled signal according to the different radial velocities of the sea clutter and the water surface micro-motion signal relative to the detection direction of the pulsed Doppler radar to obtain the acoustic time-domain waveform of the underwater acoustic wave target; the radar is controlled to hover at the intensity center according to the position of the maximum echo amplitude of the acoustic time-domain waveform, and the radar PRF parameter is adjusted according to the echo amplitude until the acoustic time-domain waveform is synchronized with the radar detection pulse, realizing the spatio-temporal synchronization and time synchronization of the underwater acoustic wave and the airborne radar wave, and providing technical support for the actual combat application of cross-media detection.

The present disclosure provides a kind of water flow rate and silt thickness measurement method, device, equipment and medium based on pulse Doppler, it is related to fluid measurement and pipeline monitoring technical field.The method comprises: obtaining Doppler echo signal and ultrasonic echo signal;Based on the Doppler frequency deviation information corresponding to the scattering echo signal of different water layers in Doppler echo signal, the water flow rate of different water layers in pipeline is determined;Based on the attenuation echo signal of silt layer in Doppler echo signal, the water body height between water surface and the interface between water body and silt in pipeline is determined;Based on ultrasonic echo signal, the liquid level height between water surface and pipeline bottom in pipeline is determined;Based on liquid level height and water body height, the thickness of silt layer in pipeline is determined.Thereby, the measurement efficiency and measurement accuracy of water flow rate and silt thickness can be improved.

The invention discloses a radar and photoelectric combined calibration method and calibration device, and belongs to the technical field of radar calibration. According to the method, errors caused by environmental interference can be effectively avoided through the certainty of the static position, so that high-precision calibration is realized; the calibration method disclosed by the invention reveals the basic principle of radar static calibration, establishes a set of complete signal processing method, is highly consistent with the actual engineering test result, ensures the scientificity and reliability of the method, and further ensures the measurement precision and stability of the calibration method. Besides, the calibration device provided by the invention is simple in structure and low in cost, and compared with traditional calibration equipment, the calibration device does not need to be physically connected with the radar and can be flexibly placed at any position, so that the complexity of installation and use is greatly reduced. The wireless connection design not only simplifies the operation process, but also improves the applicability and portability of the device, and is generally used for external field calibration of the pulse Doppler system radar.

The embodiments of the present disclosure disclose a filtering method and system for ultrasonic imaging. The method may include: obtaining a plurality of pulse Doppler echo signals, two adjacent pulse Doppler echo signals being distributed at intervals in a time domain; generating a plurality of discontinuous segments of IQ data by demodulating the plurality of pulse Doppler echo signals; for each segment of IQ data, performing first filtering on at least part of data points; and obtaining a segment of filtered IQ data by performing second filtering on the filtered data points and unfiltered data points; performing interpolation based on the plurality of segments of filtered IQ data; and generating a spectrum image based on the interpolated data.

The invention discloses an ultrasonic spectrum Doppler signal reconstruction method and device and imaging equipment. The method aims to solve the problem of intermittent lack of pulse Doppler signals caused by B-mode scanning insertion in an ultrasonic duplex mode. The method comprises the following core steps: firstly, continuously collecting a section of pulse Doppler signal, and learning a patient specific dynamic coefficient by using a sparse autoregression model; then during duplex operation, high-precision interpolation compensation is carried out on a signal containing a missing point by using the coefficient; constructing a pseudo-random observation matrix based on a Poisson disk sampling criterion, and sampling the interpolated signal; and finally, combining the observation data and introducing an interpolation signal as a priori, and reconstructing a complete time domain signal through a compressed sensing algorithm. The method can adapt to physiological features of different patients, while the real-time performance is guaranteed, the accuracy and continuity of spectrum reconstruction are remarkably improved, artifacts are effectively eliminated, and more reliable hemodynamic information is provided for clinical diagnosis.

The present invention discloses an ultrasonic pulsed Doppler blood flow measurement method and device. The blood flow measurement method includes: determining the physical position of a pulsed Doppler probe; based on the physical position of the current probe, determining an array formed by the arrangement of a plurality of array elements in the probe and determining the edge position of the array; based on the blood flow direction at the position to be detected, adjusting the positions of the sub-arrays for transmitting and receiving ultrasonic waves to shift towards the edge position to determine the positions of the sub-arrays; and performing ultrasonic pulsed Doppler blood flow quantitative measurement based on the positions of the sub-arrays. By only modifying the physical positions of the array elements participating in the current electronic beam synthesis, the steering angle is automatically enlarged, and even the steering angle that may have reached the limit (plus or minus 20 degrees) configurable by the user can be further enlarged to automatically meet the measurement included angle requirements of Doppler to the greatest extent.

The invention provides a pulse Doppler radar target distance-Doppler feature modulation method based on a phase modulation surface. The pulse Doppler radar target distance-Doppler feature modulation method comprises the steps of 1, presetting a coded modulation waveform; 2, modulating the position characteristics of the false target; 3, speed characteristic modulation of the false target; and step 4, deception of the CFAR detector is carried out. The PSS-based PD radar target distance-Doppler feature modulation method is innovatively provided, and the application of the PSS in the aspect of radar target multi-dimensional feature joint modulation is expanded. According to the invention, the cost is lower, the system complexity is lower, and the electromagnetic concealment is stronger. By applying different coding waveforms to the PSS feature modulation reflector, flexible and diversified feature modulation styles can be generated, the limitation of the traditional PD radar passive feature modulation method on functions of limited effect, insufficient flexibility and the like is overcome, and the advantage of reusability of an active feature modulation technology is also taken into account.

The application particularly relates to a pulse Doppler echo simulation method of a rotor unmanned aerial vehicle, which comprises the following steps: equivalent to a machine body as an isotropic scattering point, simulating a radar echo signal of the machine body based on an RCS of the machine body scattering point and a distance between the radar and a machine body gravity center; equivalent to rotor blades as a group of uniformly distributed isotropic scattering points on straight lines, simulating a radar echo signal of the rotor scattering points based on an RCS of the rotor scattering points and a distance between the rotor scattering points and the machine body gravity center; simulating a radar echo signal of a single blade based on the radar echo signal of the rotor scattering points, simulating a radar echo signal of a single rotor based on the radar echo signal of the single blade, simulating a radar echo signal of all rotors based on the radar echo signal of the single rotor; and simulating a pulse Doppler echo signal of the rotor unmanned aerial vehicle based on the radar echo signal of all rotors, the radar echo signal of the machine body and an echo signal noise. The method more truly simulates a radar echo characteristic of the rotor unmanned aerial vehicle.

This specification discloses a filtering method and system for ultrasound imaging. The method includes: acquiring multiple pulse Doppler echo signals, with adjacent pulse Doppler echo signals distributed at intervals in the time domain; demodulating the multiple pulse Doppler echo signals to generate discontinuous multi-segment IQ data; for each segment of IQ data: filtering at least a portion of the data points; and recursively filtering the filtered data points and the unfiltered data points to obtain segmented filtered IQ data.

The present invention discloses a method for identifying the flow pattern of gas-liquid two-phase flow in a pipeline based on pulse Doppler technology. Based on the pulse Doppler principle, the difference in Doppler frequency shift and amplitude of echo signals between the gas and liquid phases is utilized, the Doppler signal in the echo signal is extracted through an orthogonal demodulation method, and a time-frequency spectrum is drawn using short-time Fourier transform. The size of bubbles in the measurement channel is then judged based on the time-frequency spectrum, thereby identifying the flow pattern of the fluid in the pipeline. The method has the advantages of fast detection rate, high accuracy, stable performance and wide application range.

The invention particularly relates to a pulse Doppler echo simulation method for a rotor unmanned aerial vehicle, which comprises the following steps: enabling a fuselage to be equivalent to an isotropic scattering point, and simulating a radar echo signal of the fuselage based on the RCS of the scattering point of the fuselage and the distance between a radar and the gravity center of the fuselage; rotor blades are equivalent to a group of isotropic scattering points uniformly distributed on a straight line, and radar echo signals of the rotor scattering points are simulated based on the RCS of the rotor scattering points and the distance from the rotor scattering points to the gravity center of the fuselage; simulating a radar echo signal of a single blade based on the radar echo signal of the rotor wing scattering point, simulating a radar echo signal of a single rotor wing based on the radar echo signal of the single blade, and simulating radar echo signals of all rotor wings based on the radar echo signal of the single rotor wing; and simulating a pulse Doppler echo signal of the rotor unmanned aerial vehicle based on the radar echo signals of all the rotors, the radar echo signal of the fuselage and the echo signal noise. According to the method, the radar echo characteristics of the rotor unmanned aerial vehicle are simulated more truly.

The embodiment of the invention provides a pulse Doppler filling data determination method and device and electronic equipment. The method comprises the following steps: acquiring reference Doppler data before and / or after a to-be-filled time period, wherein the reference Doppler data is obtained through scanning of Doppler ultrasonic equipment; performing spectrum analysis on the reference Doppler data to obtain corresponding reference spectrum information; and predicting Doppler data to be filled in the time period to be filled based on the reference frequency spectrum information to obtain target Doppler data, target frequency spectrum information corresponding to the target Doppler data being determined based on the reference frequency spectrum information. The target Doppler data obtained through prediction by the scheme is relatively accurate, and the scheme is relatively small in calculation amount and can be suitable for an application scene of real-time scanning.

The application belongs to the technical field of short-range radar signal processing, and provides a pulse Doppler short-range radar signal processing simulation method based on a multi-scattering point model. The application simulates and realizes the working process of the pulse Doppler short-range radar under the condition that a short-range body target is locally irradiated by a radar, and uses a multi-scattering point structure to approximately construct a body target scattering source model capable of generating a return signal. The return signal of the part of the rigid body target irradiated by the transmitted signal is calculated, the return signals in the same range gate are superimposed to form the overall return signal of the body target, the return signal containing noise is demodulated and filtered, and then the frequency domain constant false alarm detection and the time domain threshold detection are used for target detection, so that the target starting point information is obtained. The technical scheme provided by the application can guarantee the influence of the target surface details on the effective return signal amplitude, and can also consider the calculation efficiency of the short-range radar signal simulation and the target starting point information.

The application relates to an ultrasonic imaging method, an ultrasonic imaging device, an ultrasonic imaging equipment and a storage medium. The method comprises the following steps: encoding original transmission pulses of each array element according to a preset encoding mode, and transmitting the encoded transmission pulses to a target region; receiving echo signals of the target region through each array element, and extracting clutter signals from the echo signals according to a decoding mode corresponding to the encoding mode to obtain denoised echo signals; and performing ultrasonic imaging on the denoised echo signals to obtain a pulse Doppler image of the target region. The method can improve the accuracy of the obtained pulse Doppler image of the target region.

The application provides a multi-pulse repetition frequency (PRF) based integrated sensing and communications (ISAC) waveform design method, which improves the range ambiguity problem of the ISAC system. First, the full-duplex ISAC node transmits different PRF waveforms in multiple coherent processing intervals (CPIs), and under each PRF, fixed-length sensing signals and variable-length communication symbols are transmitted in turn. Second, the full-duplex ISAC node knows the transmitted sensing waveform, and performs target echo matched filtering. Third, the full-duplex self-interference and noise are reduced through pulse-Doppler processing. Finally, when the target is detected in all CPIs, the target apparent time delay in each CPI is obtained according to the range-Doppler matrix, the real time delay is solved by combining the remainder theorem, and the real distance of the target is estimated. The waveform method designed by the application has the ability to resist range ambiguity, significantly expands the maximum unambiguous range, and improves the detection probability and distance estimation accuracy of long-distance targets.