35 results about "Maximum amplitude" patented technology

The invention discloses an ultrasonic head wave positioning method, device and equipment, and the method specifically comprises the steps: determining the head wave threshold value ratio of a transducer, the head wave threshold value ratio is determined according to the characteristics of the transducer, and specifically comprises the steps: calculating according to the head wave threshold value and the head wave amplitude value or the head wave threshold value and the maximum amplitude value of the transducer in a zero flow state; and selecting an initial value of a head wave threshold value, measuring a maximum amplitude value and a head wave amplitude value, and updating the head wave threshold value. Whether wrong waves occur is judged according to the relation between the head wave threshold value and the head wave amplitude value or the relation between the head wave threshold value and the maximum amplitude value, then the head wave amplitude value is adjusted, the head wave position is accurately positioned, and time measurement errors caused by wrong waves are avoided. According to the invention, accurate threshold value updating can be realized only by adding an amplitude value measuring unit or utilizing the existing amplitude value measuring unit and cooperating with a head wave threshold value ratio register and a judgment mechanism of the head wave threshold value ratio register.

The invention provides an azimuth transverse wave remote detection data processing method, system and device and a medium. The method comprises the steps that an instrument is adopted to collect novel four-component transverse wave data (xx, xy, yx and yy) of a target well section; under a coordinate system (x, y) of the instrument, synthesizing an XX reflected wave signal with an angle defined relative to the x-axis direction of the instrument by using the orthogonal dipole four-component reflected signal, and defining the XX reflected wave signal as an angle when the reflected wave signal reaches the maximum amplitude; obtaining two cross component signals xy and yx by using novel four-component shear wave data (xx, xy, yx and yy), performing sliding windowing on the cross component signals xy and yx, performing Fourier transform on the signals in the window to obtain phase spectrums, and comparing the phase spectrums of the two cross component signals to obtain an actual phase difference; according to a novel four-component data combination mode, changing the orientation of the reflector, theoretically calculating the theoretical phase difference between the two cross component signals xy and yx, and establishing a rule chart of the cross component signals along with the orientation change of the reflector outside the well based on the theoretical phase difference; and judging the real azimuth angle of the reflector according to the rule plate.

The invention discloses a single-photon laser ranging method based on laser pulse frequency modulation deblurring, and belongs to the field of laser ranging. In the ranging process, two different pulse frequency references are firstly set to correspond to two coding code elements respectively, n-bit random codes are generated according to n-time non-fuzzy distance expansion requirements, it is guaranteed that the n-bit random codes do not have displacement symmetry, then a laser source is made to repeatedly emit corresponding pulse signals according to a sequence represented by the random codes, then echo signal sequences are received, and the pulse frequency references correspond to the two coding code elements respectively. And performing cross-correlation operation on the single photon accumulation histogram and a pulse sequence represented by a known random code to obtain an operation result, determining one of the single photon accumulation histograms with the maximum amplitude, and calculating a histogram time position corresponding to the result, namely, calculating a distance measurement result of de-blurring. According to the method, the problem of range ambiguity of pulse radar ranging can be solved, the time sliding sequence matching method proposed in cross-correlation operation has the advantages of being efficient and flexible, and the time complexity of cross-correlation operation is effectively reduced.

The invention discloses a first-motion wave reverse time migration method and system based on excitation amplitude. The method comprises the steps of obtaining seismic wave field calculation parameters, performing forward continuation on a seismic source wave field, identifying a first-motion wave of the seismic source wave field, and reserving the maximum amplitude and the corresponding time of the first-motion wave on each space grid node. Carrying out reverse time continuation on a wave detection point wave field; and on each space grid node, according to the excitation time, carrying out cross-correlation on the maximum amplitude of the seismic source wave field and the detection point wave field at the same moment, and superposing cross-correlation values at all moments to obtain a reverse time migration result. According to the method, the maximum amplitude and the time of the first-motion wave are stored in the propagation process of the seismic source wave field, and then cross-correlation imaging is performed on the seismic source wave field and the detection point wave field, so that the calculated amount and the interference of multipath waves can be reduced while the reverse time migration imaging capability is ensured, and the signal-to-noise ratio is improved.

The invention discloses a vortex electromagnetic wave modal purity estimation method and system based on main lobe ripple measurement, a storage medium and electronic equipment. The method comprises the following steps: measuring the electric field amplitude and phase of vortex electromagnetic waves in a free space; finding a vortex electromagnetic wave beam center through phase distribution; gradually determining the position of a vortex electromagnetic wave main lobe by taking the beam center as a circle center; calculating the average amplitude and the difference between the maximum amplitude and the minimum amplitude along the circumference where the main lobe is located, and calculating the relative main lobe ripple; and finally, calculating to obtain the modal purity of the vortex electromagnetic wave. According to the invention, the modal purity of the generated vortex electromagnetic wave can be accurately calculated, the subsequent collection and processing of the received data are facilitated, and the influence of the waste of the collected information caused by the modal aliasing can be effectively reduced.

The present invention discloses a method and system for reverse time migration of first-arrival waves based on excitation amplitude, including obtaining seismic wavefield calculation parameters, forward extension of the source wavefield, identification of the first-arrival waves in the source wavefield, and preservation of the maximum amplitude and corresponding time of the first-arrival waves at each spatial grid node; reverse time extension of the detection point wavefield; and cross-correlating the maximum amplitude of the source wavefield with the detection point wavefield at the same time according to the excitation time at each spatial grid node, and superimposing the cross-correlation values at all times to obtain the reverse time migration result. By preserving the maximum amplitude and time of the first-arrival waves during the propagation of the source wavefield and then performing cross-correlation imaging with the detection point wavefield, the present invention can reduce the computational complexity and interference from multipath waves while ensuring the reverse time migration imaging capability, thereby improving the signal-to-noise ratio.

The invention provides a high-precision DDS quantization error suppression method based on curvature adaptive segmentation. According to the technical scheme, the method comprises the steps that firstly, the curvature of a sine function at different positions and the bending degree of a function curve are analyzed, and optimal segmentation processing is conducted on the function; 2, selecting interpolation selection of a high-curvature region by analyzing a linear interpolation error and a quadratic interpolation error; and 3, selecting a segmentation density and interpolation method by setting a target error. And 4, performing parameter optimization on the secondary interpolation of the high curvature region through a Minimax criterion and a Levenberg-Marquardt iterative algorithm. And 5, calculating a frequency control word of the high curvature area by using the iteratively optimized data. And 6, calculating a conventional sine frequency control word of a low curvature area and generating a signal through a lookup table ROM. According to the invention, the quantization error of the traditional DDS is reduced, the maximum amplitude error is reduced to 0.1 LSB from 0.5 LSB (12 bits) of the traditional linear interpolation, the curvature is adaptively segmented, the Minimax quadratic interpolation is optimized, and the problem of high curvature region error is solved.

The application discloses a laser self-mixing interference displacement measurement method and device based on complex exponential transformation, and the method comprises the following steps: S1, obtaining a self-mixing interference signal P; S2, constructing a complex exponential self-mixing interference signal X by taking i*P as an index i*P , wherein X is a base number; S3, performing time-frequency transformation on the complex exponential self-mixing interference signal X i*P , to obtain a time-frequency matrix M=[t, f, A], wherein t is time, f is frequency, and A is a corresponding matrix amplitude; S4, extracting a maximum amplitude A t corresponding to each time t t , denoted as an instantaneous frequency, and constructing a new matrix N=[t, f t ]; S5, performing integration on the instantaneous frequency f t , to obtain a reconstructed displacement at the time t. The application is free from the dependence of a target motion direction on an advance estimation based on a time-frequency spectrum integral reconstruction algorithm, and high-precision real-time reconstruction of a steady-state or non-steady-state displacement is realized.

Disclosed systems and techniques are directed to improving chucking of substrates using stress-compensation beams with multiscale irradiation doses. The techniques include decomposing a profile of a deformation of a substrate into a plurality of harmonics, and identifying, using chuckability reference data, one or more harmonics of the plurality of harmonics having an amplitude above a maximum amplitude capable of being flattened by a predetermined clamping pressure exerted on the substrate by a chuck. The techniques further include determining, based at least on a subset of the one or more harmonics, settings of a stress-modulation beam, forming a stress-compensation layer (SCL) on the substrate causing a modification of the deformation of the substrate, and irradiating the SCL with the stress-modulation beam, wherein the stress-modulation beam causes a reduction of the deformation of the substrate.

The invention discloses an active target speed estimation method and system based on generalized cross-correlation, and relates to the technical field of speed estimation, and the method comprises the steps: obtaining a transmitting signal and a reference signal, presetting the transmitting signal and the reference signal, transmitting the transmitting signal, receiving an echo signal, and transmitting the echo signal to a target target. Calculating generalized cross-correlation of the echo signal and the reference signal based on a preset weighting function of generalized cross-correlation to obtain a vector; and obtaining a peak value with the maximum amplitude in the vector as a time delay value of the first sub-pulse, detecting a peak value with the maximum amplitude in a speed range based on a preset target, taking the peak value with the maximum amplitude as a time delay value of the second sub-pulse, and calculating based on the time delay value of the first sub-pulse and the time delay value of the second sub-pulse to obtain an estimated target speed.

The present invention discloses a novel wavelet transform modulus maximum calibration method based on distribution fault traveling wave location, including: performing wavelet transform decomposition and reconstruction on fault traveling wave data to obtain the waveform of the reconstructed first-layer high-frequency detail coefficients; dividing the time horizontal axis of the waveform of the reconstructed first-layer high-frequency detail coefficients into several equal-length time periods, each time period containing the same number of time points, and sequentially marking the maximum amplitude of the waveform of the reconstructed first-layer high-frequency detail coefficients in each time period. Starting from the amplitude at the 0 time point of the original reconstructed waveform, sequentially connecting the maximum amplitudes of each time period to obtain the upper envelope of the original reconstructed waveform. On this basis, extract all modulus maxima and their corresponding time points in the upper envelope. Finally, set a floating threshold value, compare all modulus maxima with the floating threshold value, and obtain the arrival time of each fault wave head according to the time point corresponding to the modulus maximum, thereby completing the calibration.

The present invention discloses a fast calibration and calculation method for improving the measurement accuracy of beam position and a fast calibration system, including: The method includes: Step 1, start the full-automatic calibration process, the signal generator generates an excitation signal, samples the signal using the reflected signal to obtain a sampling result, and calibrates the phase and amplitude of the cable; Step 2, based on the fast sampling method, adopt the undersampling method to achieve fast amplitude-phase extraction; Step 3, add a rotation matrix to normalize the IQ data; Step 4, among them, the reference clock, adopt a coherent manner with the beam signal, can be phase-shifted, to achieve the detection of the maximum amplitude, and ensure the maximum improvement of the signal-to-noise ratio to the greatest extent.

The invention discloses a sine frequency modulation carrier suppression method based on modulation depth extraction, and relates to the technical field of sine frequency modulation interference high-precision phase demodulation. In the prior art, the modulation depth is difficult to obtain with high precision, the carrier suppression is insufficient and periodic nonlinear errors are generated, so that the phase demodulation precision is limited. The method comprises the following steps: acquiring an interference signal formed by measuring light and reference light in a common path, mixing the interference signal with a periodic window function, performing spectral analysis, acquiring a rough modulation depth by using a maximum amplitude point, subdividing near a main peak to obtain a high-precision modulation depth, constructing a matched carrier based on the modulation depth, and multiplying the matched carrier with a mixing signal to realize carrier suppression. And performing low-pass filtering and orthogonal demodulation to obtain a high-precision phase. According to the method, the modulation depth extraction accuracy and the carrier suppression capability can be remarkably improved, the phase demodulation precision is improved, and the method is suitable for high-precision interferometer measurement scenes such as precision distance measurement, deformation monitoring and displacement detection.

The invention relates to a sediment sound wave dissipation factor measurement method and system, processing equipment and a storage medium, and the method is characterized in that the method comprises the steps: determining an excitation waveform for carrying out a simulation test on a test pure waveguide phenomenon and an excitation waveform for carrying out an indoor transducer test on a test sample in a dissipation factor measurement system; based on the determined excitation waveform, performing a simulation test on the test pure waveguide phenomenon to obtain a simulation receiving end voltage, and further determining a simulation maximum amplitude; based on the determined excitation waveform, performing an indoor transducer test on the test sample in the dissipation factor measurement system to obtain a wave velocity and a test receiving end signal, and further determining the maximum amplitude of the test; according to the simulation maximum amplitude and the test maximum amplitude, the dissipation factor only considering absorption attenuation is calculated, and the method can be widely applied to the technical field of geotechnical tests.

The invention discloses a seismic exploration data regularization processing method and device. The method comprises the following steps: converting to obtain a wave number spectrum data volume based on time-space domain seismic data; carrying out the following regularization processing on the wave number spectrum of each frequency slice in the wave number spectrum data volume: determining the maximum amplitude in the amplitude spectrum of the wave number spectrum of the current frequency slice according to the inclination angle weight function, carrying out the least square optimization on the wave number component corresponding to the maximum amplitude, and updating the wave number spectrum of the current frequency slice in combination with a Grubrum matrix; returning to continue to execute the step of the maximum amplitude until the preset number of iterations is reached, and obtaining the wave number spectrum after the regularization processing of the current frequency slice; and obtaining a regularized wave number spectrum data body based on the regularized wave number spectrums of all the frequency slices, and converting to obtain time-space domain seismic data. According to the method, the reconstruction result is accurate, the pseudo Gibbs phenomenon is improved, the spatial sampling attribute of the data is improved, and the seismic exploration data imaging quality is improved.

Disclosed systems and techniques are directed to improving chucking of substrates using stress-compensation beams with multiscale irradiation doses. The techniques include decomposing a profile of a deformation of a substrate into a plurality of harmonics, and identifying, using chuckability reference data, one or more harmonics of the plurality of harmonics having an amplitude above a maximum amplitude capable of being flattened by a predetermined clamping pressure exerted on the substrate by a chuck. The techniques further include determining, based at least on a subset of the one or more harmonics, settings of a stress-modulation beam, forming a stress-compensation layer (SCL) on the substrate causing a modification of the deformation of the substrate, and irradiating the SCL with the stress-modulation beam, wherein the stress-modulation beam causes a reduction of the deformation of the substrate.

The invention discloses a broadband digital multi-beam joint detection method and system based on large beam amplitude selection, and belongs to the field of signal processing. Digital multi-beam forming is carried out on AD channel echo data of a receiving array plane; uniformly dividing the broadband signal into N paths of parallel narrowband channels according to a preset frequency interval by adopting a multi-filtering channelization technology; for the same channel, comparing each range gate signal amplitude of all beams on the channel, selecting a value with the maximum amplitude as the amplitude of a virtual detection beam of the channel, and performing signal detection; in each channel, according to the start of the signal envelope, comparing the average amplitude at the initial position of the envelope, determining a wave beam with the maximum amplitude as the arrival direction of the signal, marking the wave beam number of the signal as the wave beam, and switching the original data of the wave beam as the input of fine measurement; and in each channel, measuring each parameter of the signal by using the data of the selected beam.

The application discloses a single-photon laser ranging method based on laser pulse frequency modulation deblurring, and belongs to the field of laser ranging. In the ranging process, two different pulse frequency references are set to correspond to two encoding code elements, n-bit random codes are generated according to n times non-blurring distance expansion requirements, and the n-bit random codes are ensured to have no shift symmetry, then a laser source repeatedly emits corresponding pulse signals according to a sequence represented by the random codes, then a sequence of echo signals is received, a single-photon cumulative histogram is obtained, and a cross-correlation operation is performed on the single-photon cumulative histogram and the pulse sequence represented by the known random codes to obtain an operation result, one having the maximum amplitude in the operation result is determined, and a histogram time position corresponding to the operation result is calculated, that is, a ranging result without blurring can be calculated. The application can overcome the distance blurring problem of pulse radar ranging, and the time sliding sequence matching method proposed in the cross-correlation operation has the characteristics of high efficiency and flexibility, and effectively reduces the time complexity of the cross-correlation operation.

The invention discloses an LFMCW radar ranging method based on an improved Rife algorithm, and belongs to the technical field of radar signal processing, and the method comprises the steps: carrying out the calculation of an original signal of an LFMCW radar transmitting signal through employing the improved Rife algorithm, judging an interpolation direction, calculating a frequency shift factor, obtaining the value of the frequency shift factor, solving an amplitude value through employing a frequency spectrum refining technology, and carrying out the calculation of the amplitude value, according to the method, a Rife algorithm can be improved, an interpolation direction is judged by utilizing a phase difference between a spectral line with the maximum amplitude and a spectral line with the adjacent second maximum amplitude on two sides, and a frequency shift factor is changed according to different regions in which a real frequency is located, so that a target distance is obtained. Simulation experiments are carried out at different frequencies and frequencies under different SNRs, the performance is better than that of other algorithms, and the finally calculated target distance is more accurate.

The invention relates to an automatic adjustment method of an ultrasonic flaw detection gate, which is applied to a flaw detector and comprises the following steps: in the process of performing scanning flaw detection on a to-be-detected workpiece by using the flaw detector, determining the actual thickness of the to-be-detected workpiece based on an initial wave signal and a bottom wave signal obtained by scanning flaw detection of the flaw detector; calculating a bottom wave moment based on the actual thickness of the workpiece to be measured, wherein the bottom wave moment is the time corresponding to the maximum amplitude point of the bottom wave signal; determining a bottom wave gate of the to-be-detected workpiece based on the bottom wave moment, and determining an initial wave gate of the to-be-detected workpiece based on the initial wave signal; and determining a target flaw detection gate of the to-be-detected workpiece based on the initial wave gate and the bottom wave gate. The problem that in the prior art, the measurement precision of a continuous variable-thickness workpiece in the ultrasonic scanning process cannot be guaranteed is solved.

The invention discloses a parameter optimization method based on a transmission-type terahertz time-domain spectroscopy system, which comprises the following steps: firstly, collecting air and sample time-domain signals, performing Fourier transform to convert the air and sample time-domain signals into frequency-domain signals, then performing phase extraction and solution to obtain a phase difference between the air and sample time-domain signals, correcting the phase difference, and then obtaining an amplitude ratio by using a complex projection function; finding the maximum amplitude ratio and calculating the initial refractive index, inverting and optimizing the thickness by using a time domain signal, and calculating optical parameters such as the refractive index, the extinction coefficient and the dielectric constant based on the thickness. According to the method, optical parameter calculation of a sample of which the thickness cannot be directly measured is realized.

The invention relates to a method for determining starting and ending time and starting and ending frequency of a signal based on time-frequency analysis, which is characterized by comprising the following steps of: on the basis of a time-frequency analysis image and a related method, firstly, extracting frequency data in a signal frequency range in pairs, judging starting and ending time of an effective signal in a time domain after judging the effective signal in the frequency domain; and taking out the continuous time section and the continuous time length of the corresponding effective signal, finding out the maximum amplitude, and further determining the start-stop frequency and time of the effective signal. Judging whether an effective signal exists at the position or not according to the data characteristics in the frequency and time starting and ending positions; the method has the advantages in the application aspect of determining the frequency and time starting and ending positions of the signal, especially the burst signal.

The application provides a radio direction finding system and a multi-beam switching amplitude comparison direction finding method. The method comprises: constructing an amplitude difference sample library; receiving a target source signal through an antenna array, and controlling a time delay unit and an attenuation unit connected with each array element to switch beams with different spatial directions on a receiving channel; obtaining the amplitude of the target source signal under each beam; calculating the measured amplitude difference between the first beam with the maximum amplitude and the second beam with the second largest amplitude according to the amplitudes under all beams; matching the amplitude difference sample library according to the frequency of the target source signal and the number of the first beam to obtain a coarse azimuth; and calculating the actual azimuth of the target source signal based on the coarse azimuth through an interpolation algorithm. The application switches multiple beams with different directions, matches and interpolates calculation based on the pre-generated amplitude difference sample library, and realizes high-precision and high-stability radio azimuth measurement.

The invention relates to a compressed sampling system suitable for high dynamic range broadband signals and a rapid reconstruction method, and the method is used for processing aero-engine blade tip vibration monitoring signals. Based on the signal Nyquist rate fNYQ, the bandwidth B, the effective frequency band number K and the maximum amplitude Amax, hardware parameters of a modulation broadband converter MWC and a threshold value of a self-recovery analog-to-digital converter SR-ADC are set in a priori mode; performing multi-channel frequency band demodulation, low-pass filtering and analog-to-digital sampling on the signal by using a modulation broadband converter and a dual-threshold self-recovery analog-to-digital converter to obtain the output of each channel; correct amplitude information is recovered from the collected signals according to the dual-threshold information, and continuous signals are constructed to a finite field conversion module; adaptively solving a spectrum support set by using variational Bayesian inference, energy aggregation, FDR saliency detection and a BIC model reduction algorithm; and performing up-sampling and frequency band modulation on the low-rate sample sequence based on the frequency spectrum support set, and reconstructing a high-dynamic range time domain signal meeting the Nyquist rate and a complete frequency spectrum located in an original frequency band.

The invention discloses a high-speed multi-target distance and speed joint estimation method, device and program product, relates to the field of radar signal processing, and is used for obtaining a stable and reliable multi-target distance and speed joint estimation result. FRFT processing is carried out on echo signals, peak points are extracted from an amplitude matrix of a processing result, effective peak points are screened out, effective target energy rays are extracted according to the effective peak points of each row, smooth filtering processing is carried out on the effective target energy rays, and the effective target energy rays are obtained. And finally, estimating the distance and the speed of the corresponding target according to the angle sampling value and the u-axis projection value of the effective peak point with the maximum amplitude on each effective target energy line. According to the method, the influence of the target speed on the radar echo frequency modulation slope is considered, the estimation result is more accurate, the joint estimation of the distance and the speed is realized on the single-cycle echo, and the average effect of multiple cycles is avoided.

The invention provides a self-adaptive estimation method for window length in SAR (synthetic aperture radar) self-focusing, which comprises the following steps of: S1, traversing an image distance dimension, and finding an amplitude maximum value Am of each distance unit to form a first array A (m), m representing a distance unit number; s2, amplitude maximum values Am in the first array A (m) are ranked from large to small, a ranked second array A '(m) is formed, a first distance dimension position array corresponding to the second array A' (m) is R (m), and a calculation formula of a distance dimension position Rm included in the first distance dimension position array R (m) is Rm = i * delta R, i is the distance unit number m corresponding to the maximum amplitude value in the second array A '(m), and delta R is the distance resolution of the image; s3, performing clustering processing according to the first distance dimension position array R (m) to obtain a clustered second distance dimension position array R '(m'); and S4, selecting the image of the second distance dimension position array R '(m') in the image, and estimating the azimuth dimension window length according to the image amplitude. According to the invention, the self-focusing performance is improved, and the imaging effect is enhanced.

The invention provides a medium repetition frequency PD radar time-frequency domain two-dimensional sliding window ambiguity resolution method and device, and the method comprises the steps: 1, carrying out the distance dimension and speed dimension extension of a distance trace point formed by a multi-frequency period radar echo in an observation range, and determining all possible position and speed information of a target; step 2, quantizing the observation area according to the set quantization unit parameters, and marking all targets in a nine-square manner at the same time; 3, sliding window detection is sequentially carried out on the observation areas after quantitative marking in a matts mode, and whether a target exists or not is judged according to an M / N detection criterion; and 4, detecting and judging the existing target through the step 3, extracting target information by taking the maximum amplitude as a criterion, and clearing the identifier of the observation area of the target. According to the method, the difficulty and the calculation amount of fuzzy understanding are greatly reduced, and meanwhile, the generation of false plots is also reduced by utilizing distance and speed information.

The invention discloses a laser self-mixing interference displacement measurement method and device based on complex exponential transformation. The method comprises the following steps: S1, obtaining a self-mixing interference signal P; s2, taking an imaginary number unit i * P as an index, and constructing a complex index self-mixing interference signal Xi * P, where X is a base number; s3, time-frequency transformation is carried out on the complex exponential self-mixing interference signal Xi * P, a time-frequency matrix M = [t, f, A] is obtained, and t is time; f is frequency; a is a corresponding matrix amplitude; s4, extracting a frequency ft corresponding to the maximum amplitude At at each moment t, recording the frequency ft as an instantaneous frequency, and constructing a new matrix N = [t, ft]; and S5, carrying out integration on the instantaneous frequency ft to obtain the reconstruction displacement at the t moment. The method gets rid of the dependence of a reconstruction algorithm based on time-frequency spectrum integration on pre-estimation of a target motion direction in advance, and realizes high-precision real-time reconstruction of steady-state or unsteady-state displacement.

The invention provides a missile-borne bistatic forward-looking SAR time-frequency synchronization method based on direct waves, and the method comprises the steps: carrying out the data demodulation of a received direct wave signal, and carrying out the distance compression of the demodulated direct wave signal; extracting a peak signal with the maximum amplitude of each sampling pulse in the direct wave matrix after distance compression to form a peak signal vector, and performing Doppler centroid estimation on the peak signal vector; performing polynomial fitting on peak position historical data corresponding to peak signals in each sampling pulse, extracting linear components, eliminating deviations corresponding to Doppler centroids, obtaining an offset rate of a linear time synchronization error, and compensating the linear time synchronization error according to the offset rate; the peak phase of the peak signal is subtracted, deviation corresponding to the Doppler centroid is eliminated, an estimated value of the fixed frequency synchronization error is obtained, and the fixed frequency synchronization error is compensated according to the estimated value. According to the method, the time-frequency synchronization error between missile-borne double-base foresight SAR platforms can be effectively eliminated, and high-quality imaging in the whole guidance process is guaranteed.

The present application discloses an angle measurement method, device, terminal and medium based on angle correction, the method comprising: obtaining the DBF angle measurement curve of the target; obtaining the maximum amplitude and the second largest extreme value of the target DBF angle measurement curve; if the difference between the maximum amplitude and the second largest extreme value is less than a preset value, it is judged that there are two target angles; when the absolute value of the azimuth difference of two targets with the same speed and distance is within 0.73~1.4 times of the 3db beam width, there is a linear relationship between the absolute value of the angle difference of the two targets and the angle complement value, and the angles of the two targets are corrected respectively according to the linear relationship; when the absolute value of the azimuth difference of the two targets is between 1.4~1.5 times of the 3db beam width, the angle complement value is a constant. The logic of the angle correction of the two targets is to subtract the complement value from the measured small angle and add the complement value to the large angle. The present application can obtain target angle measurement with higher accuracy and solve the problem of inaccurate angle measurement of targets with the same speed and distance.