147 results about "Echo intensity" patented technology

The embodiment of the invention provides a radar echo extrapolation prediction method and system based on a test time training strategy. According to the embodiment of the invention, the method comprises the steps: carrying out the time axis calibration and space grid alignment processing of a radar echo historical collection sequence collected by an atmosphere detection system, and generating radar echo sequence data with time-space consistency; constructing an echo evolution relevance representation model based on the data, and generating an echo evolution dependency graph and a multi-step extrapolation initial condition set; then introducing a test time training strategy to carry out adaptive prediction processing, and adjusting edge weight parameters in real time to obtain a radar echo multi-step extrapolation prediction sequence with time dynamic characteristics; and finally, according to the sequence, extracting an echo intensity change characteristic and a space movement track rule, and combining historical climate cycle evolution data to generate a climate evolution trend description set containing an echo intensity trend curve and a path offset vector so as to realize more accurate climate evolution prediction and weather forecast.

The invention relates to a lightning potential forecasting method and system based on a random forest. The method comprises the following steps: (1) collecting and preprocessing multi-source meteorological data; (2) feature extraction: cloud picture texture and shape features are extracted from satellite data, and echo intensity, top height and vertical development speed features are extracted from radar data; (3) constructing and optimizing a model; and (4) early warning thunder and lightning. The method has the advantages that the random forest serves as a typical representation of the ensemble learning algorithm, and the core of the random forest is to integrate prediction results of a plurality of decision trees. According to the integration mode based on Bagging, multi-dimensional feature information can be fully integrated, and the overfitting problem which is likely to happen to a single decision tree is effectively restrained. In a thunder and lightning potential forecasting scene, the algorithm can accurately capture a complex nonlinear relationship between meteorological elements and thunder and lightning potential by adaptively learning association between a large amount of historical meteorological data and thunder and lightning events, so that the forecasting accuracy is remarkably improved.

The invention provides a monitoring method and system for the conveying state of grain capable of being washed based on multi-mode sensing. Multi-axis laser speed measurement probes with dust covers are arranged on the two sides of the conveying belt, so that interference of dust to a light path is eliminated. Laser Doppler frequency shift signals of surface particles and echo intensity data of deep particles are synchronously collected, and a hierarchical control volume model is established; and utilizing the echo intensity to compensate the scattering signal, and generating a flow velocity distribution profile map through self-correlation processing. A particle motion vector field is further constructed by adopting an optical flow method, and a collision energy value is calculated through vector field energy distribution. When the energy value exceeds a preset threshold value, a positioning early warning signal is generated, and real-time monitoring and accurate positioning of particle collision abnormity are achieved. According to the technical scheme, full-dimension monitoring of the particle motion state in the grain conveying process can be achieved in the high-dust environment, collision abnormity is effectively recognized, the fault area is accurately positioned, and the grain conveying quality is guaranteed.

The invention discloses a target detection method, device and equipment based on millimeter wave radar, a storage medium and a program product. Determining a distance-Doppler map based on the echo signal received by the millimeter wave radar; determining the angle of each target based on the phase echo signal of each target; filtering the targets based on a first set threshold value and the echo intensity of each target to obtain candidate targets; determining second detection thresholds corresponding to different angles and / or different speeds; and filtering the candidate targets based on the second detection threshold, the echo intensity of each candidate target and the angle and / or speed of each candidate target to obtain a final detection target. According to the target detection method based on the millimeter wave radar provided by the embodiment of the invention, weak targets, false noise targets and sidelobe false targets caused by strong targets can be effectively filtered out, so that the accuracy of target detection is improved, and calculation resources for performing angle estimation on the targets subsequently are further saved.

The invention relates to the technical field of laser ranging, in particular to a novel railway tunnel deformation real-time surveying and mapping system based on a three-dimensional scanning technology, which comprises a laser sampling module, an echo evaluation module, a space repositioning module, a residual evolution module and a deformation surveying and mapping module. According to the method, after continuous distance information of a target position is obtained, measuring point sequence data is constructed based on a time sequence, a signal abnormal area is recognized through echo intensity fluctuation, the signal abnormal area is further converted into a space coordinate structure, track differences are extracted, vector data are generated, deviation characteristics are analyzed in combination with the tunnel space position, and the deformation amplitude is quantified. Compared with a periodic observation mode depending on manual distribution of measuring points, the method has the advantages that fine coordinate difference data can be continuously output, the deformation monitoring frequency and the space coverage range can be improved, manual interference errors can be reduced, and the dynamic mastering capability of the tunnel structure evolution process can be enhanced.

The invention provides a suspended sediment concentration inversion method capable of resisting particle size interference, which comprises the following steps of: standardizing the original acoustic echo intensity of each observation grid to obtain the standardized volume back scattering intensity; establishing a sonar equation considering the sound wave attenuation of the sediment particles, and performing explicit processing on the sonar equation considering the sound wave attenuation of the sediment particles to obtain an explicit inversion model which resists particle size interference and considers the on-way change of the sediment particle size; and performing model parameter calibration on the explicit inversion model, and performing suspended sediment concentration inversion on the river observation section based on the suspended sediment concentration inversion value of each observation grid. According to the method, the dependence of ADCP inversion of the suspended sediment concentration on suspended sediment particle size distribution is effectively eliminated, and the stability and accuracy of suspended sediment concentration inversion are improved. The particle size interference resistant explicit method can realize continuous and real-time suspended sediment concentration monitoring, and is suitable for various water environments such as rivers, lakes, reservoirs and the like.

The invention provides a metasurface structure and a metasurface structure preparation method, and relates to the technical field of electromagnetic wave regulation and control. The metasurface structure comprises a frequency selection layer, an isolation layer and a reconfigurable gradient impedance layer, the frequency selection layer is located above the isolation layer; wherein the frequency selection layer is used for receiving a first electromagnetic wave incident at a first angle and inhibiting the echo intensity of scattering of the first electromagnetic wave; the reconfigurable gradient impedance layer is located below the isolation layer; wherein the reconfigurable gradient impedance layer is used for receiving a second electromagnetic wave incident at a second angle and inhibiting the echo intensity of scattering of the second electromagnetic wave; wherein the first angle is smaller than the second angle. According to the application, the echo intensity of mirror scattering is suppressed through the frequency selection layer, and the echo intensity of non-mirror scattering is suppressed through the reconfigurable gradient impedance layer, so that electromagnetic scattering suppression of a wide angular domain is realized.

The invention belongs to the technical field of feature recognition of underwater complex targets, and relates to a boundary element-based multi-bright-spot cluster target interference feature estimation method, which comprises the steps of geometric model construction and introduction, numerical calculation based on multi-physics field coupling, echo intensity representation by adopting an angle-frequency spectrum, and analysis of resonance generated by multi-body interference. According to the method, a numerical model for solving a three-dimensional double-gas-cylinder omnidirectional scattering sound field is established based on a boundary element method, and omnidirectional and broadband scattering characteristics of a target in horizontal and vertical attitudes are calculated; a multi-bright-spot dual-target strong scattering coupling mechanism is mainly analyzed, and a multi-body configuration and single target scattering interference fringe generation mechanism is disclosed; according to the method, the inherent attribute characteristics of the single target can still be effectively identified in a cluster target scattering field; the mapping relation among the geometric configuration, the spatial arrangement mode and the frequency response is obtained, and a theoretical formula suitable for double-target sound scattering forecast is deduced.

The invention provides a method and a system for identifying environment abnormity in a direct-current battery swap station. The method comprises the following steps: fusing multi-source images acquired by the direct-current battery swap station; determining at least one suspected abnormal region based on the fused image; constructing a three-dimensional structure model of an object in the suspected abnormal area based on reflection deformation information of structured light projected into the suspected abnormal area for multiple times; determining reflection change information of the object in the suspected abnormal area based on reflection echo intensity and reflection echo time of the obtained ultrasonic wave on the surface of the object in the suspected abnormal area; and performing logic correlation analysis based on the three-dimensional structure model and the reflection change information, and determining a target abnormal region in the to-be-identified direct-current battery swap station. According to the method and the system, the capability of identifying tiny and hidden abnormal objects of the direct-current battery swap station is greatly improved, missed judgment is effectively reduced, the accuracy and the reliability of environment abnormity identification in the direct-current battery swap station are improved, and stable operation of the battery swap station is guaranteed.

The invention relates to a radar echo three-dimensional visualization method, device and equipment, a medium and a program product. The method comprises the following steps: acquiring radar scanning data, and constructing a three-dimensional point set based on the radar scanning data; dynamically adjusting the grid resolution in the longitude, latitude and height directions according to the spatial distribution characteristics of the three-dimensional point set to obtain a three-dimensional grid; after an adaptive threshold is determined, segmenting the three-dimensional grid, aligning the dimension of the block with the thread group number of the graphics processor, and synchronously executing table look-up and edge interpolation on each block by adopting a parallelization moving cube operator to generate a three-dimensional contour surface representing specific echo intensity; and carrying out local coordinate centralization and binary block packaging processing on the three-dimensional contour surface, exporting a preset format, and loading to a three-dimensional view to obtain a three-dimensional visual radar echo. Therefore, the million-level voxel processing time can be shortened from the minute level to the second level, the timeliness is greatly improved, and the method has wide application prospects in the fields of meteorological early warning, environment monitoring and the like.

The invention relates to the technical field of computer graphics, sensor simulation and real-time rendering, in particular to a panoramic laser radar simulation method and system based on a single GPU calculation shader, and the method comprises the steps: receiving simulation parameters of a laser radar sensor, assembling the simulation parameters into a constant buffer area object, and carrying out the simulation of the laser radar sensor on the constant buffer area object; the method comprises the following steps: allocating a structured point cloud buffer area and binding shader resources in a rendering dependency graph framework, scheduling and calculating a shader to generate a two-dimensional thread index, calculating a light beam direction vector corresponding to each thread and constructing a ray descriptor based on the two-dimensional thread index, and obtaining hit information; the method comprises the steps of calculating echo intensity based on hit information according to a preset intensity model, simulating noise, writing point cloud attributes into a structured point cloud buffer area, and asynchronously looking back point cloud data for consumption through the structured point cloud buffer area. And the throughput and the data consistency are improved.

The invention relates to the technical field of data processing, in particular to an efficient monitoring and intelligent irrigation management platform for radar rainfall data. Obtaining a first abnormal point location and a non-initial abnormal point location according to a data volume feature in an intensity data cluster of the echo intensity and a data difference feature of the intensity data cluster; obtaining a point location connected domain according to the intensity data cluster of the non-initial abnormal point location; obtaining a spatial noise feature value according to the position distribution feature between the point location connected domains and the data difference feature in the point location connected domains; obtaining a time noise characteristic value according to the historical echo intensity of the non-initial abnormal point location; obtaining a second abnormal point location according to the spatial noise characteristic value and the time noise characteristic value; correcting the corresponding echo intensity according to the position features of the first abnormal point location and the second abnormal point location; and the rainfall is determined according to the corrected echo intensity, and the irrigation rule is adjusted, so that the accuracy of rainfall judgment and irrigation regulation is improved.

The application relates to the technical field of ultrasonic detection, and discloses a welding seam defect detection method and system based on ultrasonic waves, which comprises the following steps: establishing a historical database, and traversing ultrasonic echo signals in the historical database; determining a multiplexing defect strategy or an ultrasonic checking strategy according to a traversal result; when the ultrasonic checking strategy is determined, determining a first ultrasonic result based on echo delay and echo intensity, determining a second ultrasonic result based on ultrasonic echo signals and an ultrasonic characteristic model, determining whether a welding seam to be detected has defects according to the first ultrasonic result and the second ultrasonic result; performing Fourier transform on the ultrasonic echo signals, determining a defect type of the welding seam to be detected based on an ultrasonic characteristic spectrum, determining an attenuation result based on a three-dimensional model and a metal sample, and writing the attenuation result into a simulation database of a simulation environment; and verifying the defect type based on the relationship between an ultrasonic characteristic spectrum and a simulation spectrum curve. The application ensures the reliability and stability of ultrasonic detection.

The invention relates to the technical field of marine geological survey, in particular to a shallow sea sediment classification method and system based on multi-scale and multi-direction feature fusion, and the method comprises the steps: obtaining the multi-source acoustic data of a shallow sea sediment, and carrying out the preprocessing of the obtained multi-source acoustic data, constructing a spatial correlation model based on the preprocessed multi-source acoustic data, performing submarine topographic feature extraction according to a water depth value of MBES data, performing multi-scale and multi-direction texture feature extraction by using an SSS image output by the spatial correlation model, performing feature optimization on the obtained topographic features and texture features, and taking a core feature set as an input to perform feature extraction on the obtained topographic features and texture features; according to the method, the echo intensity image is taken as a core, the problem of poor space consistency in traditional multi-source data registration is solved, classification errors caused by feature space dislocation are avoided, and the accuracy of the multi-source data registration is improved. And classification reliability is improved.

The invention relates to the technical field of mobile robot environment perception and navigation, in particular to a storage environment depth map generation and processing method based on laser vision. Comprising the following steps: an original data acquisition and point cloud construction step: acquiring multi-dimensional original echo data including geometric distance, echo intensity and pulse width, and constructing an initial three-dimensional point cloud; a light-object interaction characteristic decoupling step: analyzing light intensity attenuation and pulse width broadening characteristics, and constructing an intensity distance material mapping model; a material analysis and confidence generation step: analyzing the data to identify high reflection, light absorption deficiency and semitransparent areas, and generating a pixel-level confidence tensor; a semantic enhancement depth map generation step: restoring abnormal pixels based on tensor and endowing physical trafficability semantics to generate a semantic enhancement depth map; according to the invention, the problem of visual deception is effectively solved, and the passing efficiency in a complex storage environment is improved.

The invention relates to the technical field of smart bracelets, and discloses a swimming stroke-based bracelet track positioning method and device and computer equipment, wrist nodes are obtained based on a human body model, and a swing area of a radar sensing assembly is obtained according to the wrist nodes, so that the motion range of a bracelet can be known through the swing area; swimming stroke information of a user in a preset time period is obtained based on the swing area of the user, the distance between each part and the radar sensing assembly and the time from sending to receiving are used for comprehensively representing the swimming stroke, and the adaptation degree of the user in water can be known through the underwater sensing coefficient. According to the technical scheme, the radar echo intensity can be calculated through the swimming stroke information and the underwater induction coefficient, whether the current swimming stroke is accurate or not can be known by judging the radar echo intensity, and when the current swimming stroke does not meet the preset condition, prompt information can be generated to remind a user, so that the bracelet effectively recognizes whether the swimming stroke is correct or not.

The present application relates to the technical field of concrete height measurement, and provides a concrete pouring height self-adaptive monitoring method and system, which controls a motor drive cloud platform to drive a laser ranging module to automatically scan a monitoring area and determine an effective monitoring point through an edge computing terminal, and sequentially performs automatic measurement, thereby improving monitoring real-time performance and reducing labor costs. During the monitoring process, when the ranging value suddenly changes and the echo intensity meets a preset condition, the cloud platform is controlled to swing and the maximum ranging value in the swinging process is taken as an effective value to actively avoid shielding and obtain a real concrete liquid surface distance. The number of consecutive invalid points is accumulated to automatically eliminate the invalid points, and new points are obtained by supplementally scanning near the eliminated points when the points are insufficient, thereby realizing automatic updating of the monitoring point set. The inclination of the device is obtained in real time through an inclination sensor, and the ranging value is accurately converted into pouring height in combination with the absolute installation height, thereby eliminating the device inclination error. The present application has low implementation cost and is convenient to deploy.

The application provides a kind of based on multimodal sensing of bad grain conveying state monitoring method and system. Wherein, by arranging the multi-axis laser speed probe with dust cover on both sides of the conveying belt, eliminate the interference of dust on light path. Synchronous acquisition of surface layer particle laser doppler frequency shift signal and deep layer particle echo intensity data, establish layered control body model. Use echo intensity to compensate scattering signal, generate flow velocity distribution profile by autocorrelation processing. Further adopt optical flow method to construct particle motion vector field, calculate collision energy value through vector field energy distribution. When the energy value exceeds the preset threshold, generate positioning early warning signal, realize real-time monitoring and accurate positioning of particle collision anomaly. The technical scheme provided by the application can realize full-dimensional monitoring of particle motion state in the process of bad grain conveying in high dust environment, effectively identify collision anomaly and accurately locate the fault area, and ensure the quality of bad grain conveying.

The invention discloses a visualization method for marine survey shallow stratum profile data, which is applied to the field of marine survey, and comprises the following steps: extracting acoustic echo samples, navigation data and attitude data from JSF format data collected by a shallow stratum profiler, analyzing the JSF format data into a JSON format containing the original echo intensity, geographic position and attitude information of each Ping, and analyzing the JSON format data to obtain the marine survey shallow stratum profile data. The method comprises the following steps of: firstly, dividing a local sub-block, mapping the local sub-block into an initial gray level image matrix, then enhancing the initial gray level image matrix by adopting CLAHE, and generating a high-contrast profile image capable of clearly identifying the characteristics of the seabed shallow layer structure by dividing local sub-blocks, calculating a local histogram cumulative distribution function and redistributing pixel values. According to the method, the data accuracy is ensured, the accuracy and the efficiency of interpreting the submarine pipeline burial depth and the stratum structure by interior interpretation personnel are improved, the data processing cost is reduced, the readability, the transportability and the compatibility of the data are improved, and a standardized interface can be provided for long-term management of ocean survey data and application of different platforms.

The invention provides a dual-polarization weather radar time domain echo simulation method based on Doppler spectrum reconstruction, and the method comprises the steps: constructing a scanning region and a resolution volume grid, dividing a sub-resolution volume grid, and carrying out the interpolation of the sub-resolution volume grid through a trilinear interpolation method; micro-physical information and a scattering matrix of each phase-state particle are calculated, echo intensity contributions are superposed along a speed coordinate axis of a Doppler spectrum and then are sequenced, a horizontal polarization channel Doppler spectrum of each sub-resolution volume grid is obtained, and an antenna pattern is taken as a weight and is superposed, so that a horizontal polarization channel Doppler spectrum of a resolution volume grid is obtained; and obtaining the power spectrum density of the horizontal polarization channel through coordinate transformation, obtaining the IQ echo sequence of the horizontal polarization channel through inverse Fourier transformation, and obtaining the IQ echo sequence of the vertical polarization channel in combination with the differential reflectivity factor, the differential propagation phase shift and the co-polarization correlation coefficient. According to the invention, reliable simulation of time domain echoes in the weather process of any shape spectrum can be realized.

The embodiment of the application provides a radar echo extrapolation prediction method and system based on a test time training strategy. The embodiment of the application first performs time axis calibration and spatial grid alignment processing on a radar echo historical collection sequence collected by an atmospheric detection system, to generate radar echo sequence data with time and space consistency; then constructs an echo evolution correlation representation model based on the data, to generate an echo evolution dependency graph and a multi-step extrapolation initial condition set; then introduces a test time training strategy for adaptive prediction processing, to adjust the edge weight parameter in real time, to obtain a radar echo multi-step extrapolation prediction sequence with time dynamic characteristics; finally extracts echo intensity variation characteristics and spatial movement trajectory rules according to the sequence, and generates a climate evolution trend description set containing an echo intensity trend curve and a path offset vector in combination with historical climate period evolution data, to realize more accurate climate evolution prediction and weather forecasting.

The invention discloses a laser measurement system for the size of a rubber sealing element, and relates to the technical field of laser measurement, and the system comprises a signal collection module S11 which is used for obtaining distance measurement signal data collected by a laser distance measurement device in a continuous measurement process on the surface of the rubber sealing element, the ranging signal data comprises a scanning angle, laser emission time, laser echo receiving time and laser echo intensity; the stable screening module S12 is used for extracting signal segments with continuous angles and emission time intervals lower than a preset interval value according to scanning angles and laser emission time in the ranging signal data, and marking the signal segments as stable scanning segments; according to the method, through synchronous acquisition of distance measurement signal data, stable screening of credible signal fragments and high-precision fitting of radial dimension data, accurate reconstruction of the target contour dimension of the rubber sealing element and improvement of dimension consistency judgment capability are realized.

The invention relates to the technical field of underwater acoustic imaging and three-dimensional reconstruction, in particular to an underwater three-dimensional imaging method based on an orthogonal sonar system. Performing feature extraction based on the horizontal sonar image and the vertical sonar image to obtain a horizontal feature point set and a vertical feature point set; performing feature clustering processing to form a plurality of target candidate regions; feature points from different sonars are located in a unified spatial reference coordinate system; performing feature matching between the horizontal feature point set and the vertical feature point set based on the spatial position information and the echo intensity information of the feature points to obtain matched feature point pairs; and fusing the distance and azimuth information in the horizontal sonar image and the distance and elevation angle information in the vertical sonar image, calculating the position coordinates of the target feature points in the three-dimensional space, and generating three-dimensional point cloud data of the target. The problem that elevation angle information of the two-dimensional sonar is lost is effectively solved, and the system cost and the structural complexity are reduced.

The invention provides a ground material type detection method and equipment, which can be applied to the technical field of autonomous mobile equipment. The method comprises the following steps: transmitting ultrasonic waves to the ground, and receiving echoes of the ultrasonic waves to obtain an echo waveform diagram; the longitudinal axis of the echo waveform diagram is positively correlated with the echo intensity, and the transverse axis of the echo waveform diagram is positively correlated with the time; identifying wave troughs in the echo waveform graph; determining the number of echo groups in the echo waveform diagram according to the wave troughs; and determining a ground material type according to the number of the echo groups. The ground material type is detected through the number of the echo groups of the ultrasonic waves, and the detection accuracy of the ground material type can be improved. Moreover, only one ultrasonic sensor is needed to detect the type of the ground material, the occupied space is small, and the cost of the autonomous mobile equipment is reduced.

The application discloses a kind of self-adapting segmented gain multi-wavelength laser ranging method and system, method includes: multi-wavelength laser is under the control of trigger signal, laser pulse is emitted by emission optical system, trigger mode has synchronization, equal interval and coded emission.Laser echo is guided to detector by receiving system, and digital signal is generated after conversion by segmented gain module.Control processing module includes the information of ranging value, echo intensity in signal processing calculation.By self-adapting segmented gain, low magnification gain circuit is used to suppress strong signal in short distance, high magnification gain circuit is switched to improve weak signal detection ability in long distance, and step gain is formed by gain partition, and segmented area is adaptively adjusted to avoid distortion according to echo ranging value.Control processing module will complete data transmission.Near distance signal distortion and long distance signal missing detection are avoided, and system reliability and detection ability are improved.

The application discloses a wave intensity detection method and related device, electronic equipment and storage medium, wherein the wave intensity detection method comprises: fitting a numerical mapping relationship between wave intensity and echo intensity of a radar in advance; based on the measurement data of the wave scanning of the radar, a wave line is detected; whether each frame of measurement data successively detects a wave line crossing a detection line, and the wave line crossing the detection line is taken as a target line, and a clustering set of the target line detected by a straight line is taken as a target set; wherein the detection line is parallel to the end line of the wave, and is away from the radar relative to the end line; based on the numerical mapping relationship, the echo intensity of each measurement point in the target set is mapped respectively, and the wave intensity when the target line crosses the line is obtained. The above scheme can improve the accuracy, stability and scene adaptability of wave intensity detection.

The invention relates to the technical field of laser radars, and particularly provides a 2D laser radar point cloud data processing method. The method comprises the following steps: setting a distance threshold value and an echo intensity threshold value of data processing; obtaining a circle of point cloud data, and obtaining a radar actual measurement distance and echo intensity; retaining the point cloud data with the distance smaller than the preset distance, and setting the data points larger than the distance as invalid values to obtain a circle of new data set; judging the boundary of the target object according to the invalid value to obtain an index value of the boundary; according to echo intensity characteristics, setting sliding windows and sliding times, comparing echo intensity mean values in adjacent windows, if a difference value is greater than a set threshold value or reaches the set sliding times, retaining the point cloud and quitting data processing, otherwise, deleting the edge broadening points. According to the method, the broadening problem of the edge of the target object is effectively eliminated, and the real contour of the scanned target object is restored.

The application relates to the technical field of submarine pipeline investigation, and discloses a submarine pipeline acoustic-optical combined investigation method, system, device and medium. An AUV carrying an acoustic sensor is used to carry out coverage investigation on a task area, acoustic data are collected, and acoustic characteristics of an object to be investigated are extracted, a suspected pipeline candidate area is generated based on echo intensity in the acoustic characteristics and a preset acoustic detection threshold; an AUV carrying an optical imaging device is used to carry out fine imaging on the suspected pipeline candidate area, optical data are collected, and optical characteristics of the object to be investigated are extracted, clustering analysis is carried out based on the optical characteristics to obtain a clustering result containing a suspected target cluster, a noise cluster and an uncertain cluster; and a multi-modal information fusion method is used to jointly judge the object to be investigated according to the acoustic characteristics and the optical characteristics of the suspected target cluster. The wide-area coverage advantage of the acoustic and the high-resolution advantage of the optical are fused, and efficient, accurate and reliable investigation of the submarine pipeline is realized.

This application provides a method for identifying the depth location of underwater biological aggregation layers, comprising: identifying the upper and lower boundaries of the planktonic aggregation depth by using the position of the abrupt change in sound velocity of the temperature jump layer and the position of the change in acoustic impedance of the dissolved oxygen jump layer, obtaining the depth range of the aggregation layer boundary, and recording the depth location of the biological aggregation layer in the current cycle; determining the center depth location of the biological aggregation layer in the current cycle by combining the depth spacing, the peak depth of the scattering intensity, and the position of the abrupt change in sound velocity; identifying the depth offset between the center depth location and the depth location of the biological aggregation layer in the previous cycle, and when the offset exceeds the preset jump layer stability boundary, acquiring the echo intensity distribution of the temperature jump layer and the dissolved oxygen jump layer, and extracting the echo intensity difference value between the two jump layers; and identifying the final center depth location of the underwater biological aggregation layer using multibeam sonar by using the enhanced boundary depth location and the position coordinates of each depth point in the aggregation layer.

An echogenic needle may have at least one V-shaped spiral groove formed at its distal portion adjacent to its patient end. The walls of the groove are orthogonal to each other. The groove is titled at a given angle from a neutral position toward the proximal end of the needle so that when the needle is inserted into the patient at an insertion angle under ultrasound imaging, the ultrasound wave emitted from the ultrasound transducer is reflected in a substantially reverse direction back to the transducer by at least one wall of the spiral groove. A pair of crisscrossing grooves may be spirally wound about the distal portion of the needle with each groove being tilted to the given angle to enhance echogeneity. The echogeneity of the needle may also be enhanced by increasing the pitch density of each groove while maintaining the crisscrossing groves at their neutral position.