13 results about "Maximum amplitude" patented technology

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 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.

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 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.

A first arrival wave reverse time migration (RTM) method based on excitation amplitude includes the steps of acquiring calculation parameters of a seismic wave field, performing forward continuation on a source wave field, identifying a first arrival wave of the source wave field, and preserving the maximum amplitude and corresponding time of the first arrival wave; performing reverse time continuation on a receiver wave field; and cross-correlating the maximum amplitude of the source wave field with the receiver wave field at the same moment on each spatial grid node, and superimposing cross-correlation values to obtain an RTM result. In the present disclosure, by preserving the maximum amplitude and time of the first arrival wave, and cross-correlation imaging is conducted with the receiver wave field. The present disclosure can reduce the calculation amount and the interference of multi-path waves and improve a signal-to-noise ratio while ensuring the RTM imaging capability.

The invention discloses a radar signal pre-sorting method based on simultaneous multiple beams, which comprises the following steps of: reading pulse description words in a time slice, identifying N beams of which the frequencies, the pulse widths and the time differences of arrival are smaller than a set threshold value as a group of simultaneous multiple beams, simultaneously completing pulse width division and storing until all current pulses are traversed; performing angle measurement on each group of obtained simultaneous multi-beams by adopting a three-point power centroid method, compensating a beam pointing error caused by frequency deviation of a radar and a radiation source to obtain a unique accurate direction of the beams in the group, taking a beam direction with the maximum amplitude as an output beam, and replacing the direction with the accurate direction to obtain an accurate direction of the beams in the group; keeping amplitude information of other beams in multiple beams at the same time to an output beam, and eliminating other beams to complete false beam suppression; and on the basis of the output pulse flow, interval division based on system or precision requirements is carried out in a time domain, a frequency domain and a space domain in sequence, and pre-sorting is completed. According to the invention, high-precision angle measurement, false wave beam and distorted wave beam removal and pre-sorting are synchronously completed.

The invention discloses a complex-valued wavelet depth-of-field fusion method and device, a storage medium and a program product. The method comprises the steps of collecting an original image, converting the image into a complex value wavelet domain, fusing the image according to an amplitude maximum principle and recording a layer number, using a highest frequency sub-band layer number to back-source construct a texture image, fusing the texture image, and using a low frequency sub-band cascade of the fused texture image to replace a low frequency sub-band of a preliminary fused image. And inverse complex value wavelet transform is carried out on the corrected fusion image. According to the method, the low-frequency substrate is corrected on the premise that error-prone high frequency is not directly carried, low-frequency drift, halation and local contrast abnormity caused by the fact that perfect reconstruction conditions are not met in traditional complex value wavelet fusion are relieved, meanwhile, the detail sharpness is kept, and the method is suitable for microscopic imaging, macro shooting and industrial detection.