73 results about "Range gate" patented technology

The invention relates to the technical field of laser radar meteorological detection, in particular to a wind field feature detection method and device based on a laser radar, and the method comprises the following steps: S1, controlling the laser radar to execute dynamic hierarchical scanning, and generating three-dimensional laser scanning data; s2, carrying out aerosol backscattering signal preprocessing on the three-dimensional laser scanning data; s3, extracting an aerosol motion vector of each range gate, and decomposing the aerosol motion vector into a horizontal wind field component and a vertical wind field component; s4, performing spatial gradient calculation to generate a spatial gradient distribution map; s5, respectively calculating a horizontal energy spectrum and a vertical energy spectrum; and S6, outputting wind field characteristic parameters. According to the invention, through fusion of the dynamic features of the laser radar point cloud, the wind shear space gradient and the energy spectrum analysis method, precise extraction of the turbulence intensity, the main energy scale and the three-dimensional vortex features is realized, and the accuracy and the spatial resolution of wind field structure identification are improved.

This application discloses a method for combating multi-main-lobe intermittent sampling interference through multi-radar signal coordination, relating to the field of signal processing technology. It includes: expanding the summation or integration process of the matched filtering results of the signals received by M receiving nodes of a radar system along its expanded dimensions, and performing interference suppression processing along the expanded dimensions to obtain the filter output; sampling the filter output after range gate alignment, and converting it into a fast and slow time-dimensional matrix with A sampling points; performing Q-point coherent accumulation within each of the M receiving nodes' received signals, and combining this with the fast and slow time-dimensional matrix to obtain an R-D diagram of the M receiving nodes; performing P-point coherent accumulation between the receiving nodes on the R-D diagram of the M receiving nodes to obtain a two-dimensional matrix, and taking the x and y coordinates corresponding to the maximum value of the two-dimensional matrix as the target's range and velocity. This method addresses how to effectively suppress multiple intermittent sampling interferences in the absence of prior interference information.

The present invention provides a radar co-frequency asynchronous interference suppression method based on slow-time interpolation, the method comprising: extracting sample data sets X of the same range gate Nr received by the radar in the slow-time dimension. Nr_i The sample data group X Nr_i The process involves filtering to identify pulse period sequence group K containing interference signals. j And the pulse period sequence number group K that does not contain interference signals s The interference signal is restored; slow-time dimension sample interpolation is performed to obtain the processed signal X'. Nr_Kj Improve the performance of the radar.

The present invention discloses a method for designing discrete constant modulus quadrature phase coding for multiple targets. The method comprises the following steps: S1: determining the number of waveform signals M and the number of code elements N of each waveform of a multi-input multi-output radar, and randomly generating training samples of a size of M×N; S2: calculating the distance of a range gate and the waveform correlation function, and setting a loss function based on the distance and correlation function; S3: inputting the training samples into an established phase coding network for training, performing modulo-1 and discretization processing on the network output to obtain discrete constant modulus phase coding; S4: calculating the coding loss value based on the loss function, and updating the network parameters based on the loss value; S5: proceeding to S6 upon completion of training, otherwise returning to S3; S6: obtaining a trained network, inputting the data to be coded into the trained network, and obtaining a discrete constant modulus quadrature phase coded signal. This method enables the multi-input multi-output radar to operate normally in multi-target scenarios, and the output is a discrete code, which is more suitable for practical applications.

A coherent wind lidar echo signal spectrum simulation data generation method is provided, comprising: obtaining the bottom noise of the echo signal; removing the bottom noise from the echo signal spectrum data and counting the variance of the random noise; performing normalization processing on the random noise and performing Gaussian fitting to obtain the amplitude, Doppler shift and bandwidth of the echo signal; recording the Doppler shift difference between adjacent range gates to obtain the power spectrum peak energy of a single spectrum data and the correction amount of the distance; respectively counting the statistical parameters of the random variable, the power spectrum peak energy, the correction amount of the distance and the bandwidth; generating a group of wind speed profile graphs by using random walk and normal distribution characteristics of random variables, generating bandwidths under different range gates that satisfy the Lorentz distribution, power spectrum peak energies of a single simulated spectrum that satisfy the chi-square distribution, and distance correction amounts that satisfy the normal distribution; and generating a single simulated spectrum by a radar equation and repeatedly generating complete spectrum simulation data.

The present invention provides a method for suppressing folded clutter based on range gating and alternating inversion. The method estimates the range distribution interval of clutter echoes from an airborne radar based on the airborne radar scene; determines the spatial-Doppler distribution area of the clutter echoes according to the airborne radar platform parameters and the range distribution interval; determines the maximum number of range segments N for the clutter echo distribution according to the airborne radar parameters, with both the number of each range segment and its clutter echo being n; reconstructs the clutter echoes of the nth range segment using a clutter echo reconstruction submodule; and processes the reconstructed result of the clutter echoes of the range segments other than the nth range segment using a receive filter bank for the nth range segment to obtain the clutter of the nth range segment. The above steps are repeated until iterative convergence is achieved. For each range segment, folded clutter is suppressed by subtracting the reconstructed clutter outside the range segment from the total echo. The method has the advantages of low computational complexity, low complexity, and good robustness.

The invention relates to the technical field of signal processing, in particular to a detection signal noise suppression method of a laser wind finding radar. Based on spatial physical redundancy of laser radar multi-range gate observation, the technical problem that a real wind field and platform noise are difficult to separate under the frequency domain aliasing condition is solved by utilizing the physical characteristics that platform rigid body motion is a full-field common modulus and atmospheric turbulence is a spatial differential modulus. By calculating a spatial frequency standard deviation sequence, the fuzziness of pure time dimension analysis is relieved by utilizing the redundancy of spatial information. According to the technical means, a motion inversion algorithm can adaptively adjust a trajectory smoothing weight coefficient according to environmental turbulence intensity, inertial constraints are automatically reduced at a strong turbulence moment to retain high-frequency wind speed characteristics, and constraints are enhanced at a weak turbulence moment to smooth observation noise; therefore, the method achieves the accurate stripping of the common-mode motion track of the platform under a complex meteorological condition, effectively inhibits the noise of a detection signal, and improves the wind speed inversion precision.

The invention discloses an SAR intermittent sampling forwarding interference detection and suppression method based on prominent edge perception, a storage medium and electronic equipment. The method comprises the following steps: accurately detecting an interference-containing pulse sequence through a variance sequence obtained through time-frequency analysis by adopting a prominent edge perception algorithm; all interference-containing pulses are superposed in the azimuth direction to increase the difference between an interference signal component and a target signal component, and the obtained result is used for accurately positioning the ISRJ component in the echo by adopting the prominent edge perception algorithm again. And according to the time mapping relationship between the signal time domain and the time-frequency domain, obtaining the time interval, namely a distance gate, of each interference slice in the time-frequency domain, so as to design a time-frequency domain filter to suppress interference. According to the method, high interference detection and positioning precision can be achieved for typical two-dimensional intermittent sampling forwarding interference forwarding types such as two-dimensional intermittent sampling direct forwarding interference, two-dimensional intermittent sampling repeated forwarding interference and two-dimensional intermittent sampling cyclic forwarding interference, and the suppression method can achieve a good suppression effect; and useful signals can be better protected.

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.

The present invention relates to the field of aviation safety technologies, and provides a method, a system, a device, a product and a medium for lidar wake vortex inversion. The method includes: obtaining meteorological parameters, aircraft type parameters and ADS-B data, and calculating the wake vortex circulation; constructing an axial scanning coordinate system; constructing a first radial velocity algorithm; calculating the background wind velocity through the first radial velocity algorithm; constructing a second radial velocity algorithm through the background wind velocity and the first radial velocity algorithm; determining range gates and obtaining corresponding probe point coordinate pairs, and traversing the absolute values of the gradients of the probe point coordinate pairs in the set of probe points to obtain the relative vortex core position; obtaining a first true vortex core position and a second true vortex core position and the distance therebetween in the region where the relative vortex core position is located, and iterating until the distance therebetween converges to determine the true vortex core position. The present invention effectively eliminates the interference of the background wind, and realizes the axial scanning of the aircraft wake based on lidar by calculating the true vortex core position.

The invention provides a triple constant false alarm target detection and multi-frame association tracking vital sign monitoring method. The method comprises the following steps: 1, carrying out differential and normalized preprocessing on an original chirp signal (Chirp signal); 2, carrying out range gate triple CFAR detection on the preprocessed signal, carrying out multi-frame association, and extracting a target range gate; 3, performing phase extraction on the target range gate; 4, filtering and Fourier transform are carried out on the phase, and heartbeat signal spectrum energy and respiration signal spectrum energy contained in the phase are separated; 5, performing multi-frame association tracking on the heartbeat and respiration signals; and 6, outputting the frequency data of the tracked heartbeat and respiration signals. When the CFAR is used for target detection, the cooperative effect of the global threshold, the local threshold and the fixed threshold is used, and noise and interference can be effectively restrained. Meanwhile, multi-frame correlation tracking of vital signs adapts to continuity of physiological signals, and stability and accuracy of monitoring are guaranteed.

The airborne SAR real-time self-focusing imaging method comprises the following steps: estimating Doppler center frequency based on an amplitude equalization method; iterative calculation: utilizing the estimated Doppler center frequency, introducing a migration parameter correction term delta D (eta) and a frequency modulation correction term delta Km (eta), and recalculating a distance Doppler domain signal of the current iteration round; based on the improved CSA processing chain, performing phase error compensation on each range gate by using a space-variant phase error compensation function to obtain a compensated range Doppler domain signal; carrying out distance direction and azimuth direction compression in parallel to generate a focusing image, and evaluating image quality indexes; if not, extracting strong scattering points, estimating the residual two-dimensional phase error of each range gate, fitting and updating delta D (eta) and delta Km (eta), and carrying out the next round of iterative calculation; and if so, ending iteration, and outputting the focused image of the current round. According to the method, the pixel-by-pixel suppression of motion error correction and space-variant error independent of external sensing and embedded real-time imaging processing are realized.

The present invention provides a clutter suppression method based on a dual-base end-fire array airborne radar. The method constructs raw clutter echo data for all range gates, extracts unambiguous clutter data at small elevation angles to construct an unambiguous clutter covariance matrix, and then calculates a transformation matrix to transform the raw clutter echo data. Maximum likelihood estimation is performed on the transformed clutter data to obtain a filter weight vector, and clutter suppression is performed on the raw clutter echo data. The method utilizes the difference between the clutter scattering point and the incident cone angle of the transceiver platform to select an appropriate elevation angle to construct a far-field stationary unambiguous clutter covariance matrix as a reference covariance matrix for RBC compensation, thereby ensuring the stationarity of the reference clutter. Subaperture smoothing is also used to expand samples to estimate the covariance matrix, ensuring that the number of samples meets the required sample number. Furthermore, the method eliminates the non-stationarity of the clutter, thereby enabling effective clutter suppression using a space-time adaptive algorithm.

This invention discloses a method for testing the amplitude and phase characteristics of plane waves in a compact field quiet zone based on scattering measurements. It primarily addresses the shortcomings of existing methods, such as the difficulty in testing the amplitude and phase characteristics of plane waves in a compact field quiet zone and the challenge in eliminating environmental clutter interference. The implementation scheme is as follows: Spatial coordinate calibration of the area to be tested determines the coordinates of sampling points. A standard scatterer is placed at each point, and its single-station scattering data is measured. The standard scatterer is moved to the next sampling point, and this measurement process is repeated until scattering data from the standard scatterer at all sampling points are obtained. Environmental clutter in the data is filtered out using a range gate filter. The radiation pattern of the compact field feed antenna is measured, and a target scattering field compensation matrix is ​​constructed. This matrix is ​​used to compensate for the scattering of the filtered results. The amplitude and phase characteristics of the plane wave in the compact field quiet zone are calculated based on the compensation results, and the range of the compact field quiet zone is determined using these characteristics. This invention can achieve relatively simple measurement of the amplitude and phase characteristics of a compact field quiet zone and can be applied to the performance testing and analysis of compact field quiet zones.

This application discloses a respiratory and heart rate detection method and related equipment based on UWB radar, which is used to improve the accuracy of respiratory and heart rate detection. The method includes: acquiring a raw response signal; determining a target range gate for a target object within the range gate of the initial segment of the raw response signal using a first path signal detection algorithm; extracting the raw response signal from the target range gate to the Mth range gate as a valid response signal; sequentially performing short-window moving target display processing and long-window moving target display processing on the valid response signal; detecting moving human targets based on the short-window moving target display processing result; if a moving human target is detected, pausing the respiratory and heart rate detection process; detecting static human targets based on the long-window moving target display processing result; determining the range gate of the static human target; and determining the respiratory rate and heart rate of the static human target based on the range gate of the static human target.

The invention relates to the technical field of laser radars, in particular to an omnidirectional slant visibility prediction method and device based on a laser radar. The method comprises the following steps: determining a laser emission path according to a measurement area, and respectively acquiring scattered echo signal data, slant visibility data and wind data under the same range gate on the laser emission path through a micro-pulse laser radar and a coherent Doppler wind measurement laser radar; storing and processing the acquired data; and inputting the processed data into a vector autoregression exogenous variable prediction model to obtain a predicted slope visibility value at a future moment. Meanwhile, the invention discloses a device for executing the method, and the method and the device for predicting the omnidirectional slant visibility based on the laser radar are adopted, so that the slant visibility on a laser emitting path can be predicted, and technical support is provided for follow-up.

The invention discloses a space-time quick forward-looking imaging method for a forward-looking array radar of a motion platform, which comprises the following steps of: firstly, recording forward-looking area echoes by a multi-channel radar system based on a track cutting direction, and sampling to obtain distance-pulse-channel three-dimensional echo data; performing range-direction high-resolution processing, pulse compression and range migration correction on the data; traversing each range gate, performing azimuth Fourier transform on each frame-multichannel space-time two-dimensional data, intercepting a dominant Doppler unit greater than an energy threshold in a Doppler spectrum, and performing inverse Fourier transform to a time domain, namely performing dimension reduction processing in the Doppler domain; then, rank reduction processing is carried out based on the low-rank characteristic of the covariance matrix, and the energy of the signal is reserved through principal component analysis; and finally, estimating the position and amplitude information of the target through an adaptive iteration algorithm, and carrying out projection to obtain a final two-dimensional imaging result. According to the method, while the foresight resolution is effectively improved, the calculation complexity is remarkably reduced, and the operation efficiency is greatly improved.

The present invention discloses a radar measurement data processing method and device, wherein the method includes: obtaining a radar speed range Doppler map and moving target point cloud data of a measurement area at the current moment; comparing a plurality of signal power values corresponding to a plurality of range gates in parallel, and obtaining a moving target information area set of the measurement area at the current moment according to the comparison result; clustering the moving target point cloud data to obtain first moving target motion information of the measurement area at the current moment; filtering the first moving target motion information according to the moving target information area set at the current moment to obtain second moving target motion information. The present invention obtains a moving target information area set of the measurement area at the current moment through the comparison result, and obtains the first moving target motion information using a clustering method. The first moving target motion information is filtered according to the moving target information area set at the current moment, thereby obtaining more effective second moving target motion information, thereby reducing the false alarm rate of radar target detection in complex environments.

The invention discloses a multi-radar signal cooperative multi-main-lobe intermittent sampling interference resisting method, and relates to the technical field of signal processing. Comprising the following steps: carrying out dimension expansion on a summation or integration process of matched filtering processing results of received signals of M receiving nodes of a radar system, and carrying out interference suppression processing along the expanded dimension to obtain a filter output result; the output result of the filter is sampled after being subjected to range gate alignment processing and converted into a fast and slow time dimension matrix, and the number of sampling points is A; q-point coherent accumulation in the receiving nodes is carried out on the receiving signals of the M receiving nodes, and R-D graphs of the M receiving nodes are obtained by combining the fast and slow time dimension matrixes; and performing P-point coherent accumulation among the receiving nodes on the R-D graph of the M receiving nodes to obtain a # imgabs0 # two-dimensional matrix, and taking the horizontal and vertical coordinates corresponding to the maximum value of the two-dimensional matrix as the distance and speed of the target. The method and the device are used for solving the problem of how to realize effective suppression of multiple intermittent sampling interferences under the condition of no interference prior information.

The application discloses a kind of based on FPGA's step frequency high-resolution short-range radar detection system and method, the system includes: transmitting receiving combination module, for generating, sending step frequency signal, and receiving its target reflection echo signal in turn into intermediate frequency echo signal;Signal processing combination module is connected with transmitting receiving combination module and receives intermediate frequency echo signal therein;Control module is connected with signal processing combination module and receives one-dimensional range image;Signal processing combination module includes FPGA operation module, and intermediate frequency echo signal is preprocessed, velocity compensation, range gate division, high-resolution imaging, same distance selects big method to remove redundancy, timing control obtains one-dimensional range image, FPGA operation module receives the control instruction issued by control module and sends it to transmitting receiving combination module.Its advantages are: the system is detected by step frequency broadband synthesis method, and the advantages of FPGA operation module parallel processing are fully utilized, and high-resolution, high-speed signal processing is realized.

This invention provides a frequency domain imaging method for spaceborne large-angle high-resolution sliding convergence SAR, achieving high-precision imaging of spaceborne large-angle high-resolution sliding convergence SAR. This invention solves the problem of nonlinear variation of the Doppler center of each target point with azimuth time by nonlinear deskewing, and solves the problem of inconsistency of azimuth spatial variables of range migration at different range gates by azimuth resampling, thus making up for the shortcomings of the prior art.

The invention discloses a method and system for accurately estimating the inclination angle of an interference baseline of a wide-swath altimeter, and the method comprises the steps: setting a search range based on a satellite rolling angle as an initial value of the inclination angle of the interference baseline, and selecting N inclination angles in the search range; sea surface height inversion is carried out on observation data of right side view and left side view of the altimeter, averaging is carried out in the azimuth direction, one-dimensional height vectors of right side view and left side view are obtained, each vector comprises height values corresponding to M range gates, then a right side view matrix and a left side view matrix are obtained, and the sizes of the right side view matrix and the left side view matrix are both N * M; differential operation is carried out in the column direction, and a right side parallax matrix and a left side parallax matrix are obtained; calculating the absolute value of the sum of the two difference matrixes to obtain an absolute value matrix; searching a minimum value of each column, and taking a corresponding inclination angle as a preliminary estimation value of each range gate; performing error correction to obtain a corrected inclination angle estimation value; and averaging all the corrected inclination angle estimated values of the range gates to obtain a final interference baseline inclination angle estimated value.

The invention discloses an underwater sound source target detection, identification and positioning method and device based on a millimeter wave radar, and belongs to the technical field of underwater target detection, identification and positioning. The method comprises the following steps: acquiring a water surface echo signal by using a millimeter wave radar, and performing Fourier transform to obtain a distance-time spectrum; extracting a slow time phase sequence of each range gate in a radar beam coverage range, and obtaining a sound-induced water surface vibration signal after unwinding and filtering; performing correlation calculation on the vibration signal and a preset target feature library, or realizing target recognition through a deep learning model; a multi-radar cooperation or single-radar digital beam forming technology is adopted for target positioning, and large-range water area searching is achieved. According to the invention, the millimeter-wave radar is used for detecting micron-sized water surface vibration with high phase sensitivity, the defects of short distance, complex arrangement and the like of traditional acoustic and optical detection are overcome, and the system has large-range, real-time and non-contact underwater target detection and positioning capability.

The application discloses a multi-range gate wind speed inversion method based on adaptive super-noise frequency offset estimation and CNN-LSBoost fusion, and belongs to the technical field of laser radar wind measurement. In view of the problems of great wind speed inversion error caused by unstable radial frequency estimation and poor noise resistance of a four-beam Doppler laser radar under low signal-to-noise ratio, the application firstly constructs a robust power spectrum resistant to gain drift through median filtering, SG smoothing and noise section logarithmic domain normalization; then an adaptive super-noise centroid frequency offset estimation method is proposed, a local centroid weighted by super-noise power in a symmetrical window is calculated, and combined with physical constraints to remove abnormalities; then a least square method is used to synthesize a horizontal wind vector and construct a two-dimensional feature matrix of gate-beam; finally, spatial embedding features are extracted through a shallow two-dimensional CNN network, and input into an LSBoost boosting tree model to complete nonlinear regression of wind speed. The application effectively improves the precision and robustness of multi-range gate wind speed inversion under extreme complex conditions.

The invention discloses a radar signal processing method, a circuit, a virtual antenna array, an antenna array and equipment. The radar signal processing method comprises the following steps: acquiring a distance Doppler spectrum of a radar signal; for a range gate, acquiring K Doppler units with targets in the range Doppler spectrum corresponding to the range gate; for a Doppler unit with a target, determining corresponding frequency spectrum estimation by adopting an iterative adaptive IAA spectrum estimation method accelerated by fast Fourier transform (FFT); and selecting one frequency spectrum meeting a set condition from the frequency spectrum estimations corresponding to the K Doppler units with the targets as an angle spectrum of the range gate, wherein the fast Fourier transform FFT is carried out based on the K Doppler units with the target, and K is an integer greater than 0. According to the scheme, the radar signal angle spectrum is determined through FFT accelerated IAA spectrum estimation, the distance angle spectrum calculation speed is remarkably increased, and the real-time requirement of radar signal processing is met.

The invention provides an anti-vibration detection method and device and a storage medium. The anti-vibration detection method comprises the following steps: acquiring sampling data of an echo signal by a radar sensor; performing fast time dimension calculation on the sampling data according to a time sequence to generate a corresponding distance spectrum, wherein the distance spectrum comprises a plurality of distance gates; selecting a range gate where an echo signal of a static object is located from the range spectrum as a reference range gate; acquiring amplitude and phase change information of the reference range gate in a slow time dimension to form a vibration waveform; at least compensating phases of other range gates based on the vibration waveform to obtain a compensated range spectrum; and carrying out slow time dimension calculation on the compensated distance spectrum, and carrying out target detection according to a calculation result. On the basis, zero-speed clutter energy caused by vibration of the base can be prevented from being leaked to a non-zero-speed area, the static clutter suppression effect of the radar sensor in a vibration environment is improved, and the accuracy of at least a detection result of a moving target is ensured.

The present invention discloses a non-contact human vital sign detection method based on an adaptive range gate. The method comprises the following steps: Step A: mixing the echo signal obtained after transmission with the transmission signal to obtain an intermediate frequency signal, and then sampling the intermediate frequency signal to obtain a discrete signal to form a data matrix; Step B: determining the range gate where the target human body is located using a variance-based adaptive range gate selection method to obtain a preprocessed signal; Step C: extracting a human feature signal from the preprocessed signal using a variational pattern extraction algorithm; and Step D: estimating human features from the extracted human feature signal using a fast Fourier transform. The present invention deeply integrates the phase variance-based adaptive range gate selection method and the variational pattern extraction algorithm to achieve accurate estimation of human vital sign detection.

The invention discloses a dual-mode human body target detection method and device, and relates to the technical field of target detection, and the method comprises the steps: obtaining a back projection image through an SAR, carrying out the detection of a human body target, determining a candidate position coordinate, determining the wave beam direction of a candidate human body target relative to a radar antenna through A-scan, and carrying out the detection of the human body target. The main lobe is aligned with the candidate human body target, a second linear frequency modulation continuous wave signal is emitted, and a second backscattering echo signal is received; performing frequency mixing and low-pass filtering on the received signal to obtain an intermediate frequency signal; setting a distance gate based on the candidate position coordinates; acquiring an energy sum of squares of a second back scattering echo signal in the range gate; determining a peak distance unit; extracting a slow time complex sequence corresponding to the peak value distance unit; carrying out downsampling processing and fast Fourier transform on the slow time complex sequence to generate power spectrum density; and human body target detection is carried out based on the power spectrum density to improve the human body target detection accuracy.

The invention provides a range gating laser radar image reconstruction method based on an improved centroid method, and solves the technical problems that detection target signals and background noise are difficult to distinguish and reconstructed image distance information is distorted due to the fact that the intensity of existing laser radar echo signals is influenced by the difference of object surface reflectivity. The method comprises the following steps: acquiring a plurality of radar slice images, extracting the pixel intensity of a certain pixel point in the plurality of radar slice images, and drawing a pixel intensity value change trend chart; performing background judgment on the pixel intensity value change trend chart, and if the pixel intensity value change trend chart is a background, performing zero clearing on the centroid distance of a certain pixel point; otherwise, the target object is obtained, the centroid distance of a certain pixel point is calculated, iteration is carried out until all pixel points are calculated to obtain a centroid distance matrix, and pseudo-color processing is carried out to obtain a distance image of the reconstructed target object. The method can be widely applied to the technical field of laser radar imaging.

The system accurately calculates the distance to the subject even when visibility is poor in the direction of the moving object. [Solution] The system comprises a field of view determination unit that determines the field of view in the direction of travel of a moving object, a light emitter that emits pulsed light, a photoelectric conversion element having multiple pixels arranged, each having a first photoelectric conversion unit and a second photoelectric conversion unit that generate a first photoelectric conversion signal and a second photoelectric conversion signal having a predetermined parallax, respectively, a control unit that range gate controls the emission time, exposure time and exposure timing, and a distance measuring unit that calculates the distance to the subject based on the first photoelectric conversion signal and the second photoelectric conversion signal. The control unit switches between executing a process to calculate the distance to the subject based on the first and second photoelectric conversion signals generated without range gate control, or executing a process to calculate the distance to the subject based on the first and second photoelectric conversion signals generated by range gate control, based on the determination result of the field of view determination unit.