427 results about "Pulse compression" patented technology

The invention discloses a composite board ultrasonic defect detection method which comprises the following steps: S1, fixing a carbon fiber circumferential winding composite pressure container on a bracket, and establishing a coordinate system with the axis of the container as a z axis; s2, a 40 MHz dry coupling phased array ultrasonic probe is attached to the scanning starting point, and the contact angle of the probe is recorded; s3, moving the probe along the spiral track of the outer surface of the container at the speed of 20mm / s, and collecting A-scanning echo signals of all array elements; s4, performing pulse compression and time domain deconvolution processing on the acquired signal to obtain a time domain echo sequence; s5, delay time is calculated according to the shell curvature, the array element signals are compensated, and focusing B-scanning data are generated; s6, splicing the B-scanning data at the step length of 0.5 mm * 0.5 mm, and reconstructing C-scanning data corresponding to the space coordinates; and S7, inputting the C-scanning data into the trained Transform network, and outputting defect types, sizes and three-dimensional coordinates. The method realizes high-frequency ultrasonic composite board defect accurate detection, remarkably improves the microcrack recognition rate, and is widely applied to safety evaluation scenes of high-pressure hydrogen storage tanks and pressure vessels.

The invention provides a radar signal multi-target tracking method and system based on a dynamic graph convolutional network. The method comprises the following steps: acquiring a radar one-dimensional range profile sequence of a target cluster, and performing pulse compression to form a radar echo two-dimensional sequence; separating position and amplitude data of aliasing scattering points based on scattering point distribution characteristics; calculating a spatial distance between targets by using position information, constructing a dynamic edge weight in combination with a radial speed difference, and generating a shielding relation edge; aggregating neighborhood features through a dynamic graph convolutional network, and learning trajectory decoupling features of the occlusion and intersection regions; and generating association weights based on the decoupling features, inputting the association weights into a multi-hypothesis tracking algorithm, generating a multi-branch trajectory, and if the spatial distance between two branches is smaller than a dynamic threshold value and the velocity vector included angle exceeds a set angle, retaining a branch with a higher association weight, and outputting a multi-target trajectory sequence. According to the invention, the multi-target tracking precision and robustness in a shielding and trajectory crossing scene are significantly improved.

The invention provides a target positioning method and system based on a distributed networking radar system, and belongs to the technical field of radars, and the method comprises the steps: controlling a plurality of radar nodes to transmit stepping linear frequency modulation continuous wave pulse signals, and collecting target echoes; carrying out band-pass filtering, pulse compression and fast time synchronization processing on the echoes, and generating interference-free data through a moving target extraction algorithm; realizing cross-node clock synchronization based on a moving target behavior cognition model and a template matching algorithm; constructing a multi-node distance estimation equation set, generating an accurate distance value through calibration broadband synthesis and FFT, and determining a target three-dimensional coordinate; and generating a motion track and speed prediction through Kalman filtering based on the target position sequence. The system comprises a signal emission and acquisition module, a signal processing module, a clock synchronization module, a distance estimation and coordinate fusion module and a trajectory prediction module. The method supports multi-target tracking, improves positioning precision and time synchronization precision, has few errors, and is compatible with any node deployment form.

The invention belongs to the technical field of radial artery compression hemostats, and particularly relates to a radial artery hemostasis method based on real-time pulse analysis and a hemostat control system. A slow and continuously changing force is applied to a radial artery puncture opening through the pressure applying module, meanwhile, the pulse detection module transmits a pulse forced feedback signal of the puncture opening to the main control module in real time, and the main control module analyzes and processes the received feedback signal in real time and judges the current hemostatic state of the radial artery. And on this basis, the pressure applying module is controlled to adjust the pressure. The method is characterized in that the relation between pulse forced feedback signals and the forced state of the radial artery is obtained through clinical tests according to the difference of the pulse feedback signals of the radial artery in different pressed states, and therefore the pressure is stabilized in the state that the blood flow of the radial artery is stable and a puncture opening does not bleeding. According to the scheme, the individual difference between different patients can be overcome, the compression hemostasis strength is adjusted in a self-adaptive mode, and the occurrence rate of related complications such as radial artery occlusion is effectively reduced.

The invention provides an ultrasonic detection method for internal defects of an insulating part of a power system based on a piezoelectric ultrasonic transducer, and belongs to the technical field of insulating part detection. After wavelet denoising and deep attenuation compensation are carried out on echo signals, sound path distance time delay and sound pressure amplitude parameters are extracted, defect identification and position estimation are carried out by utilizing a layered variational auto-encoder, a high-frequency transducer is switched to aiming at tiny defects, a harmonic component is extracted by adopting a nonlinear ultrasonic method, and a characteristic size is calculated; a defect distribution space feature matrix is generated based on a synthetic aperture focusing technology, a unified or personalized processing strategy is selected according to an acoustic characteristic homogenization degree evaluation value, a complete defect detection result is output, and the technical problem that deep weak defects in the electric insulation part are difficult to accurately detect and recognize is solved.

The application discloses a method for simultaneously resisting suppressing interference forward-looking imaging of a missile-borne forward-looking array radar, adopts an array antenna in a cut-off track direction to receive echoes of a forward-looking area, and samples to obtain distance-pulse-array three-dimensional echo data; pulse compression in the distance direction is performed on the three-dimensional echo data, a pulse compression reference function and a migration correction factor are multiplied in the frequency domain, and high resolution in the distance direction is realized; multi-channel receiving data of each distance-pulse unit is selected, and is sequentially arranged to form a corresponding space snapshot of the unit; a covariance matrix of interference and noise is established, and the maximum likelihood estimation value of the target angle and amplitude in the interference environment is approximately solved by using an adaptive single-pulse algorithm on the space snapshot signal of each distance-pulse unit after distance pulse compression; and the angle measurement result is projected to the distance-azimuth domain, and through space coordinate conversion, a two-dimensional forward-looking imaging diagram is obtained. The application realizes high-resolution imaging of a forward-looking target while effectively suppressing main lobe suppressing interference.

The invention relates to a wind profile radar signal and data processing method and system, and the method comprises the steps: constructing a working parameter combination of a wind profile radar, and designing a radar detection mode of the wind profile radar based on the working parameter combination; the wind profile radar collects external wind field data based on the radar detection mode to obtain a wind profile radar signal; performing signal processing based on the obtained wind profile radar signal; performing pulse compression, moving target detection and Doppler spectrum analysis on the wind profile radar signal; extracting wind profile radar data from the processed wind profile radar signal, and processing the wind profile radar data; performing wind field inversion and quality control on the wind profile radar data; and constructing a three-dimensional wind field based on the processed wind profile radar data. According to the scheme, complete acquisition of weak meteorological echo signals under a clear sky condition is effectively ensured, and the accuracy of wind field inversion is improved.

The invention belongs to the field of particle accelerator microwaves, and particularly relates to a C-band compact spherical microwave pulse compression device which comprises a shell, a dual-polarization mode coupler and a circular waveguide, a spherical energy storage cavity is formed in the shell, and the circular waveguide and the spherical energy storage cavity are communicated through a coupling hole; the dual-polarization mode coupler comprises a rectangular waveguide, a butterfly-shaped matching section and a cylindrical matching section. According to the klystron radio frequency pulse compression circuit, the radio frequency pulse with the pulse width of 2.5 microseconds of the klystron can be compressed to 300ns, the average power gain in a single pulse is more than 4 times, the peak power gain is 6.3 times, and the compression efficiency is about 54%. According to the dual-polarization mode coupler, the functions of power distribution, mode conversion and polarization mode generation are synchronously realized, a TE10 mode in a rectangular waveguide is converted into two polarization TE11 modes which are equal in amplitude and orthogonal in phase, and then the two orthogonal TE114 modes are excited in a spherical energy storage cavity.

The invention discloses a generating device capable of generating an ultra-flat broadband micro comb. The generating device comprises a pump pulse generating module, a micro comb generating module and a micro comb generating module, the pumping pulse compression module is connected with the pumping pulse generation module; the high-Q-value microcavity module is connected with the pumping pulse compression module; and the micro comb detection and feedback module is respectively connected with the high-Q-value micro-cavity module and the pump pulse generation module, and is used for monitoring the output spectrum and power change of the high-Q-value micro-cavity module and adjusting the output wavelength of the picosecond pulse light according to the output spectrum and power change so as to stabilize the ultra-flat broadband micro comb. By arranging the high-Q-value micro-cavity, the spectral bandwidth of the micro-comb can be effectively expanded, and the ultra-flat broadband micro-comb is output; meanwhile, the defects that the hyperbolic secant single soliton micro-comb is poor in flatness and narrow in bandwidth are overcome, and the micro-comb has obvious advantages in the application field with high requirements for the flatness and the spectral bandwidth at the same time.

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 invention relates to a tunable high-repetition-frequency high-power multi-wavelength optical pulse generation system, which belongs to the technical field of optoelectronic equipment and is structurally characterized in that the output end of a seed pulse source (1) is connected with the input end of a repetition-frequency multiplication module (2), and the output end of the repetition-frequency multiplication module (2) is connected with the input end of a shaping optical path module (3); the output end of the shaping light path module (3) is connected with the input end of the power amplification module (4), and the output end of the power amplification module (4) is connected with the input end of the pulse compression module (5); a multi-wavelength pulse seed source is designed by using a plurality of hybrid filters, and tunable multi-wavelength, high-repetition-frequency and high-power narrow pulse output is realized by using technologies such as an MZI-Sagnac hybrid repetition-frequency multiplication structure and the like.

The invention particularly relates to an airborne SAR distance compressed domain sea clutter suppression method based on generalized gamma distribution, and the method comprises the steps: carrying out the range pulse compression processing of an echo signal received by an airborne SAR, and extracting a pure sea clutter sample from compressed data through employing a non-local sampling strategy; then, a generalized gamma distribution model is quickly fitted for the clutter samples by using an analytical method based on a second type logarithmic cumulant, and a self-adaptive detection threshold is solved through an incomplete gamma function based on the model and a set false alarm probability. And finally, according to the threshold value, carrying out judgment and filtering on distance compressed domain data, suppressing clutter regions lower than the threshold value, and meanwhile, retaining potential target signals, thereby realizing efficient and steady clutter suppression under complex sea conditions.

The invention discloses a non-contact method for measuring a three-dimensional flow velocity field in a pipeline based on acoustic Doppler, and the method comprises the steps: transmitting a focused sound beam into the pipeline, receiving an echo signal reflected by a scatterer in fluid, and generating a Doppler echo signal set covering different angles and depth positions; performing pulse compression and time-frequency analysis on the Doppler echo signal set, and calculating the sight flow velocity component of each point along the sound beam direction; calculating a three-dimensional flow velocity vector of each sampling point based on the coordinate position of each space sampling point and the corresponding sight line flow velocity component, and realizing decoupling of the flow velocity direction and size; according to the spatial distribution of the three-dimensional flow velocity vector on the section of the pipeline, a three-dimensional flow velocity field model in the pipeline is generated through interpolation fitting, and section flow and flow state characteristic parameters are calculated according to the model. According to the embodiment of the invention, the limitation that only two-dimensional or one-dimensional flow velocity can be measured in a traditional method can be broken through, and the spatial resolution and measurement precision of flow velocity field reconstruction in a complex flow state are improved.

The invention relates to the technical field of radar target recognition, and discloses a radar target recognition method and system. The method comprises the following steps: acquiring an original echo signal sequence acquired by a radar sensor, and performing noise suppression and pulse compression processing on the original echo signal sequence by using a signal preprocessing unit to generate preprocessed radar echo data; based on the preprocessed data, fusing to generate a comprehensive feature description vector of the target; a dynamically updated target feature association network is constructed, network nodes represent feature sets of different targets, network edges represent space-time association or feature similarity among the targets, and an online learning mechanism is adopted to continuously optimize a network topology structure; according to the real-time comprehensive feature description vector, gradually positioning a potential target area in the target feature association network by adopting a hierarchical focusing mechanism; and in the potential target area, a candidate target set is screened through a multi-dimensional similarity measurement algorithm, and candidate targets are sorted and output according to a feature consistency criterion.

According to the megawatt-level half-cycle power generator based on the magnetic pulse compression system, by designing the constant-current magnetic switch reset circuit and the PID voltage stabilization charging technology, the pulse jitter characteristic within 10 ns can be achieved on the premise that megawatt-level power is output, the control precision is greatly improved, and stable output of high-power pulses is achieved. The problem that pulse generated by a traditional magnetic pulse compression amplifier is large in delay jitter is solved, high-precision output of megawatt-level pulses can be achieved, the high-precision magnetic pulse compression amplifier can be applied to a high-power transmitter needing to accurately control pulse output time, the high switching frequency and high switching efficiency of an MOS tube and the pulse compression characteristic of a magnetic switch are combined, and the high-precision magnetic pulse compression amplifier is achieved. The magnetic pulse power source has the advantages of high output power and high efficiency, improves the amplitude and phase stability of the output pulse compared with the traditional magnetic pulse power source, and expands the application scene and platform.

The invention belongs to the technical field of image processing, and discloses a three-dimensional radar sub-aperture imaging deformation monitoring device and method, and the device comprises a radar which is used for collecting echo signals passing through a preset position, processing the echo signals according to frequency mixing and analog-to-digital conversion, obtaining a three-dimensional echo matrix, and outputting the three-dimensional echo matrix; the three-dimensional echo matrix and a sampling ending signal are sent to a motion compensation module; the motion compensation module is used for resampling the azimuth direction of the three-dimensional echo matrix by adopting an interpolation algorithm; the distance matching filtering module is used for performing pulse compression on the distance direction of the three-dimensional echo matrix; the migration correction module is used for carrying out migration correction on the distance direction of the three-dimensional echo matrix after pulse compression; the sub-aperture imaging module is used for calculating a three-dimensional echo matrix after migration correction according to a sub-aperture imaging algorithm; and the deformation monitoring module is used for performing interference difference processing on the three-dimensional complex image to obtain deformation data. The imaging quality and the deformation monitoring precision can be improved.

The invention discloses an electromagnetic pulse simulation method and device, electronic equipment and a storage medium, and relates to the technical field of electromagnetic pulse simulation. The pulse compression loop module is used for performing sharpening treatment to form a double-exponential waveform conforming to high-altitude electromagnetic pulse characteristics, and meanwhile, an upper polar plate and a lower polar plate of the transmission line structure module are used for converting pulse energy into a bounded wave radiation field so as to simulate the coupling effect of the high-altitude electromagnetic pulse on ground equipment; and finally, a PoE port effect experiment module is injected to evaluate the response characteristic, the damage mechanism and the system-level failure behavior, so that the problems of insufficient waveform reproduction precision, huge system size and difficulty in deployment caused by the adoption of a traditional Marx generator and a modular splicing structure in an existing high-altitude electromagnetic pulse simulation method can be solved; the technical effect of improving experiment repeatability and protection design accuracy is achieved.

The invention provides a femtosecond pulse width precision adjustment compensation device and method, and relates to the technical field of laser processing, the device comprises a mode locking seed source, a stretcher, an amplifier, a first compressor and a second compressor; the second compressor comprises a movable reflecting mirror, a climbing mirror, a grating and a grating base material; the movable reflecting mirror is configured to adjust the diffraction times of the femtosecond laser on the grating by changing the distance between the movable reflecting mirror and the grating base material; the grating base material is made of a nonlinear material and is used for generating a self-phase modulation effect under the action of femtosecond laser to realize spectrum broadening and pulse compression; precise adjustment compensation of the femtosecond pulse width is achieved by adjusting the diffraction times. The invention provides a technical scheme which not only can bear high-power and high-energy laser, but also can realize on-line precise adjustment and compensation of pulse width.

The invention discloses a unified beam control mode back projection SAR imaging post-processing method, and relates to the technical field of radar signal processing, and the method comprises the steps: carrying out the range pulse compression and side lobe suppression of original echo data; then establishing a minimum error imaging grid and performing coordinate system conversion; constructing a uniform spectrum compression function, and designing an azimuth time domain windowing function according to the relative position of the beam pointing and the grid point; integrating a unified frequency spectrum compression function and an azimuth time domain windowing function in a back projection imaging process to realize focusing reconstruction of a preprocessed signal; and finally, a high-quality post-processing image is obtained through phase error compensation. The method effectively improves the imaging precision and efficiency, and is suitable for various beam control modes.

The invention discloses a pulse compression radar accelerator generation method based on model driving, and relates to the technical field of pulse radars, and the method comprises the steps: based on a pulse compression radar signal processing flow, splitting operators according to calculation, interconnection and storage dimensions, and extracting features; defining 9 types of core components to form a parameterized component library; the components and the connection relation are combined, and an architecture description graph in a JSON format is generated; analyzing the ADG through an architecture interpreter to obtain a standardized parameter, and generating an RTL code based on a Chisel hierarchical architecture; performing simulation verification on the RTL code, pre-estimating the resource if the simulation verification is passed, and returning an error if the simulation verification is not passed; injecting expert configuration and combining with Latin hypercube sampling to obtain an initial solution set, iteratively searching a high-quality solution cluster by a TPE algorithm, resetting a parameter boundary and then switching to an ILS algorithm, and combining with a hardware rule to obtain a global optimal solution; and repeatedly executing the steps until the end conditions that the resources reach the standard and iteration reaches the upper limit are met, and outputting the accelerator architecture with the optimal resources under the target application constraint and the complete RTL code.

The invention belongs to the technical field of inverse synthetic aperture radars, and particularly relates to a tidal deformation dynamic modeling and parameter inversion method based on hybrid GRFT. The specific process is as follows: dynamic slope distance and echo modeling: aiming at each scattering point of a target celestial body, combining a radar position and introducing three-dimensional rotation correction caused by rotation to calculate a dynamic slope distance, and simulating a radar echo signal based on the dynamic slope distance; echo processing based on mixed GRFT: performing pulse compression on echo signals, compensating phase errors caused by rotation and deformation in sub-apertures by using the mixed GRFT, and performing non-coherent superposition on GRFT output of each sub-aperture; searching parameters: setting a search range of initial height and dynamic viscosity of each scattering point, setting a fitness function as non-coherent superposition energy synthesis of each scattering point, and searching in the search range until a termination condition is met; and tide deformation quantity calculation: calculating the tide deformation quantity according to the estimated values of the initial height and the dynamic viscosity of the searched scattering points.

The invention provides a mid-infrared optical frequency comb. The mid-infrared optical frequency comb comprises a near-infrared optical frequency comb seed source of a polarization-maintaining all-fiber structure; the all-fiber nonlinear amplification and pulse compression module is connected with the near-infrared optical frequency comb seed source through a polarization maintaining fiber and is used for amplifying the power of the seed light and compressing the pulse width after generating a linear chirped pulse; the all-fiber nonlinear spectrum broadening module is connected with the all-fiber nonlinear amplification and pulse compression module through a polarization maintaining fiber and is used for broadening a laser spectrum; the difference frequency module is used for receiving the laser pulse processed by the all-fiber nonlinear spectrum broadening module and generating an intermediate infrared laser pulse through intra-pulse self-difference frequency; wherein the seed source, the all-fiber nonlinear amplification and pulse compression module and the all-fiber nonlinear spectrum broadening module are connected through a polarization maintaining fiber to form an all-fiber integrated structure. By adopting the scheme, the anti-interference capability of the system can be enhanced, miniaturization and high operation reliability are realized, the debugging process is simplified, and the difference frequency efficiency is improved.

The invention provides a digital beam forming method and device based on multiple time delays and scale correction, and the method comprises the steps: determining a reference time delay group based on a plurality of reference positions divided from a corresponding breadth range in a distance direction; on the basis of the reference time delay group, performing finite impulse response (FIR) time delay filtering processing, scale transformation processing and pulse compression processing on an echo signal in sequence; and on the basis of an error compensation function, receiving scanning SCORE weighting is carried out on the signal after pulse compression, and a digital beam forming DBF composite signal is obtained. Therefore, the problems of inter-channel time delay and scale mismatch caused by view angle change in a large-breadth SAR system are effectively suppressed, the signal-to-noise ratio and the target positioning precision are improved, meanwhile, residual phase errors introduced by scale change are eliminated through an error compensation mechanism, and finally high-precision digital beam forming is achieved.

The invention discloses a main lobe suppression type polarization agility interference suppression method, which aims at main lobe suppression type interference with polarization parameters dynamically changing, and constructs a transient polarization projection vector IPPV of an orthogonal polarization receiving signal based on the orthogonal polarization receiving signal of a dual-polarization radar. And detecting polarization parameter abrupt change points of the orthogonal polarization receiving signals by adopting a heuristic segmentation algorithm, and segmenting the orthogonal polarization receiving signals by using the polarization parameter abrupt change points to obtain polarization segmented receiving signals. And aiming at polarization segmented receiving signals with different polarization parameters, obtaining interference cancellation parameters and carrying out interference suppression by utilizing a self-adaptive polarization cancellation algorithm based on a minimum variance criterion to obtain interference suppression signals. According to the interference cancellation parameters of different polarization segment receiving signals, amplitude and phase compensation is carried out on the interference suppression signals, reference signals for pulse compression are reconstructed, and after pulse compression processing is carried out, main lobe suppression type polarization agility interference cancellation and target detection are achieved.

The invention belongs to the technical field of terahertz, relates to terahertz communication, and particularly discloses a quasi-optical resonant cavity and a terahertz pulse compression system. According to the invention, the pulse generation module and the coupling compensation module are connected in parallel and are connected to the common reflector through the common coupler, so that function decoupling is realized. In a pulse compression stage, the common coupler introduces an incident terahertz wave beam into two optical paths, and destructive interference occurs between two paths of leakage signals by adjusting the coupling compensation module, so that zero coupling loss is realized, and the problem of large energy loss is solved. Meanwhile, the pulse generation module can independently adjust the optical path of the pulse generation module to control the pulse width, and the adjustment process does not affect the optimized interference condition, so that the high robustness of adjustment is ensured. In the output stage, energy is released by switching the state of the common coupler. Compared with the prior art, low-loss accumulation and robust pulse width continuous adjustment are realized at the same time, so that the terahertz pulse compression effect is remarkably improved.

This invention discloses a phase compensation method for ship targets using ISAR based on block phase gradient autofocus. The steps include: pulse compression; range cell migration correction; range-oriented block segmentation; block phase compensation; calculation of the offset between adjacent image blocks; and image block alignment and stitching. This invention performs range-oriented block segmentation of the target echo, overcoming the shortcomings of existing technologies that ignore the spatial variation of rotational phase error, leading to defocusing in ship imaging, thus improving the accuracy of phase compensation and achieving good image focusing effect. Because this invention uses a phase gradient autofocus algorithm to compensate for the phase error within each block, and then uses a cross-correlation method to align and stitch the images of each block region, it overcomes the shortcomings of parameter estimation methods, such as complexity, time consumption, and poor real-time performance, and has the advantages of simple implementation, high efficiency, and strong real-time performance.

A pulse modification apparatus includes at least one pulse stretcher for dispersive stretching of laser pulses and / or at least one pulse compressor for dispersive compression of the laser pulses, an actuator for setting a dispersion of the at least one pulse stretcher or a dispersion of the at least one pulse compressor by setting at least one manipulated variable, a controller for controlling the actuator based on a measurement signal, and an ambient sensor for detecting at least one ambient parameter as the measurement signal. The dispersion of the at least one pulse stretcher or the dispersion of the at least one pulse compressor is dependent on the at least one ambient parameter.

The invention relates to a multichannel real-time processing method and device for ultrahigh frequency river detection radar signals. The method comprises the following steps: synchronously sampling analog echo data of multiple channels to obtain a digital echo signal; based on the digital echo data, pulse compression processing is carried out, and baseband multi-channel data is output; performing memory scheduling processing on the baseband multichannel data based on a ping-pong buffer strategy to obtain continuous data blocks; based on a preset adaptive filtering weight, performing partition adaptive weighted summation filtering on the continuous data blocks to generate a clutter suppressed single-channel data matrix; performing constant false alarm rate detection based on the single-channel data matrix to obtain a target detection list; and based on the target detection list, performing visual rendering, and generating a radar detection report of the river detection radar for detection. By adopting the method, clutters can be effectively suppressed, and the credibility of the river detection radar signal is improved.

The application discloses a high-efficiency target distance migration compensation method based on Chirp-Z transformation and belongs to the field of radar target detection signal processing.The application realizes the method as follows: FFT is conducted on a reference signal and an echo signal along a fast time dimension, the fast time time domain is transformed into a frequency domain, and the echo signal is pulse compressed by conjugate multiplication, so that target echo energy is more concentrated in the fast time dimension; a Doppler ambiguity compensation function is transformed from an integer form into a fractional form, so that a compensation Doppler frequency interval is changed from a fixed value into a value that can be changed as required; a CZT formula with the fractional Doppler ambiguity number compensation function is used to transform the pulse-compressed signal, target distance migration is compensated, and the efficiency of target distance migration compensation is improved; IFFT is conducted on the fast time dimension of the signal, so that the fast time frequency domain is changed back into a time domain; and two-dimensional data containing target distance information and Doppler information are detected, so that distance and speed information of the target is obtained.

The utility model discloses a femtosecond laser pulse compression device. The femtosecond laser pulse compression device comprises an amplifier, a first half-wave plate, a compressor, a second half-wave plate, a plano-convex lens and a solid sheet group which are sequentially arranged along a light path, laser pulses output by the amplifier enter the compressor after the polarization state of the laser pulses is adjusted by the first half-wave plate, the compressor is used for pre-compensating negative dispersion, the laser pulses output by the compressor enter the plano-convex lens after the polarization state of the laser pulses is adjusted by the second half-wave plate, and the laser pulses are focused by the plano-convex lens, enter the solid sheet group, are compressed and then are output; wherein the laser pulse generates a self-phase modulation effect in the solid sheet group, and the pre-compensation negative dispersion can counteract the positive dispersion generated by the self-phase modulation effect. According to the technical scheme, a chirp mirror does not need to be arranged, the cost can be reduced, and system operation is stabilized.