126 results about "Direct wave" patented technology

The invention relates to the technical field of power system fault positioning, in particular to a power distribution network fault accurate positioning method, device and system based on the traveling wave principle, and the method comprises the steps: deploying traveling wave detection equipment at two ends of a certain section of line of a power distribution network, and enabling the traveling wave detection equipment to be used for synchronously collecting potential fault traveling wave signals; analyzing based on the acquired potential fault traveling wave signal, and screening out a fault traveling wave; in the time union set of the local time windows at the two ends, marking the fault traveling wave with the maximum peak value in the single end as a direct wave, analyzing the waveform similarity between the direct wave and the fault traveling wave arriving after the direct wave, and screening out a reflected wave according to the peak value difference; and based on the arrival time of the direct waves and the reflected waves at the two ends, calculating the distance from the fault point to the two ends of the line through a positioning formula to position the fault point. The invention aims to improve the positioning precision of the fault point in the power distribution network by analyzing the distribution characteristics of the pseudo traveling wave signal.

The invention provides an underwater positioning system combining sound ray propagation modeling and multipath interference suppression, which relates to the technical field of marine equipment and comprises a self-adaptive underwater sound sensing and environment cognition module, an environment self-adaptive sound ray propagation modeling module, a multipath suppression and direct wave extraction module and a multi-dimensional information fusion and self-adaptive positioning calculation module. The self-adaptive underwater sound sensing and environment cognition module is used for realizing multi-mode sensing and real-time environment feature recognition of underwater sound signals, and the environment self-adaptive sound ray propagation modeling module is used for constructing a dynamically updated sound wave propagation model and providing a propagation path and time constraint for positioning calculation; the multi-path suppression and direct wave extraction module is used for carrying out multi-path signal separation and extracting direct wave features with confidence marks, and the multi-dimensional information fusion and self-adaptive positioning calculation module is used for completing high-precision positioning calculation; according to the system, deep fusion of an environment model and signal processing can be realized, and the positioning precision and robustness of the underwater vehicle in a complex underwater sound environment are remarkably improved.

The invention discloses a deep rock mass fracture imaging method and system based on micro-seismic monitoring, and belongs to the technical field of geophysical exploration, and the method comprises the steps: collecting multi-channel micro-seismic event waveform data, obtaining a main seismic phase direct waveform and a scattering tail waveform through wave field separation, and carrying out the imaging of a deep rock mass fracture. Determining a three-dimensional space coordinate and an energy distribution form of the seismic source through joint inversion, carrying out clustering analysis, and constructing an initial three-dimensional space distribution form; each seismic source is regarded as an active excitation source, a scattering tail wave waveform is regarded as a reflection signal, scatterer three-dimensional point cloud data is generated through reverse time migration processing, analysis is carried out in combination with an initial three-dimensional space distribution form, and an enhanced fracture structure is formed; and finally, through topology analysis and orientation clustering, discrete scatterers are eliminated, and a fracture development map is generated. According to the method, a technical path of combining a main seismic phase direct wave inversion seismic source and a scattering tail wave inversion scatterer is adopted, high-precision and high-fidelity imaging of a deep rock mass movable fracture can be realized, and physical activity is revealed.

The invention relates to the field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle autonomous fixed-point landing control method based on an ultrasonic array algorithm, and the method comprises the steps: dividing the landing process of an unmanned aerial vehicle into a normal flight stage, a deceleration approaching stage and a near-ground landing stage, starting an ultrasonic beacon array in the approaching flight stage, and confirming the availability of a landing point; a horizontal azimuth angle, a yaw angle and a relative distance are calculated in real time in a deceleration approach stage to perform landing guidance, direct waves and multi-path reflection signals are analyzed in a near-earth landing stage, characteristic parameters such as time delay inequality and phase offset are extracted, an environment reflection space model is reversely constructed, then positioning correction is calculated, a pose fine adjustment instruction is generated, and the attitude fine adjustment instruction is subjected to attitude fine adjustment. And precise fixed-point landing of the unmanned aerial vehicle is realized. According to the method, high-precision positioning is kept under complex environment disturbance, and the stability, accuracy and efficiency of fixed-point landing of the unmanned aerial vehicle in a complex environment are improved by converting the multipath effect from an interference source to available positioning information.

The invention discloses a target detection system and method applying a millimeter wave radar, and relates to the technical field of target detection, and the system comprises a millimeter wave radar detection module, an auxiliary sensing module, a signal processing module and a data interaction module. The millimeter wave radar detection module is used for collecting direct millimeter wave signals and multipath reflection wave mixed signals through a radar. The auxiliary sensing module is used for acquiring a scene image and a vehicle motion state through a high-definition camera and an inertial measurement unit; the signal processing module is used for carrying out feature extraction and space-time filtering optimization on the collected signals; the data interaction module is used for outputting a target detection result; according to the invention, the direct wave signal and the multipath reflection wave signal in the collected signals are accurately distinguished through the specific analysis and evaluation parameters, and the authenticity of the target represented by the point cloud is verified through the analysis of the point cloud position change rate. The effect of detecting the false target point cloud appearing in the point cloud image caused by the multipath reflection wave signal is achieved.

The invention discloses an offshore field two-dimensional seismic data rapid imaging method, and relates to the technical field of seismic exploration data processing, and the method comprises the steps: obtaining SEGD format original seismic data of a target region from a seismic collection system, combining the data of each shot of each measuring line, decoding the data into internal available data, and obtaining a to-be-processed data body; and loading an observation system and assigning seismic trace header parameters according to actual acquisition parameters based on the decompiled to-be-processed data volume. According to the invention, through a multi-stage denoising and signal protection strategy, effective suppression of various sea interferences is realized, a frequency division multi-channel statistical abnormal amplitude suppression technology is adopted, zero-phase high-pass filtering is combined, low-frequency effective signals are protected while low-frequency strong-energy background noise is removed, and the noise suppression effect is improved. The direct wave cutting step further eliminates strong energy interference under a long cable condition, highlights an effective reflection signal of middle and far offset data, forms a progressive signal-to-noise ratio improvement mechanism from original data to final imaging, and improves the interpretability of seismic data.

The application discloses an active direct wave suppression method, device, computer and storage medium, which filters a received signal by using a time domain blocking matrix, suppresses an interference frequency component, and forms a new sampling sequence; and performs a discrete Fourier transform on the new sampling sequence generated after filtering to obtain a power spectrum signal after interference suppression. According to the active direct wave suppression method, device, computer and storage medium, the uniformity of a single-frequency signal in time domain sampling is utilized, alignment on a time domain waveform is realized through phase compensation, and a difference cancellation process is performed on a reference signal and an original signal, so that the frequency component is cancelled, and static reverberation is suppressed. The method is convenient to calculate, has good single-frequency direct wave interference and reverberation suppression capability, and can be used for active target detection in a single-frequency long pulse signal transmission mode, and the effective distance is improved.

The present application relates to the technical field of task scheduling processing, in particular to a task scheduling monitoring method and system based on a signal monitoring machine, comprising the following steps: capturing a mixed sound pressure signal generated by underwater base station and vehicle communication through a submerged signal monitoring machine, separating the direct wave and reflected wave components; calculating the current sound pressure channel quality score according to the frequency dispersion index of the direct wave component and the time delay dispersion degree of the reflected wave component; setting an adaptive threshold, triggering a multi-level decision response based on the deviation degree of the channel quality score and the adaptive threshold, and generating a channel degradation alarm at the same time. The present application optimizes the task resource allocation strategy while ensuring the reliability of communication, and is suitable for various complex operation scenarios such as underwater unmanned platform, emergency communication and ocean monitoring.

The invention provides an elastic wave CT (Computed Tomography) signal denoising method for improving the inversion precision of karst cave exploration, which belongs to the technical field of engineering exploration and comprises the following steps of: performing normalization preprocessing on a received signal, suppressing random noise by adaptive filtering, converting a time domain signal into an F-K domain and identifying a surface wave, filtering a surface wave signal by a Gaussian band elimination filter, and converting the F-K domain signal back to the time domain. The method comprises the following steps of: highlighting a take-off characteristic of a weak P wave covered by a strong surface wave through normalization; using a minimum mean square error adaptive filter to accurately filter random noise; subsequently converting to an F-K domain, and smoothly attenuating the surface wave through a Gaussian band elimination filter by utilizing the frequency wave number distribution difference of the surface wave and the P wave; the method realizes layered removal of random noise and surface waves, finally outputs high-purity direct P-wave signals, greatly improves P-wave travel time pickup and wave velocity calculation precision, and remarkably improves inversion precision of an elastic wave CT exploration method in detection of geologic bodies such as karst caves and fracture zones.

The application discloses a kind of distributed array high-precision time synchronization method based on compressed sensing (CS) and secondary least square (QLS), belong to wireless communication and radar signal processing technical field.For under the restriction hardware bandwidth and strong multipath environment, traditional cross-correlation method is limited by Rayleigh resolution and sampling grid, there is the problem of serious peak aliasing, insufficient synchronization accuracy, the application proposes CS-QLS joint decoupling strategy.The method constructs frequency domain observation matrix and high-density time delay over-complete dictionary by transmitting sparse multi-tone probe signal, reconstructs sparse channel impulse response using CS, separates multipath aliasing and determines direct wave coarse synchronization boundary;Further combined with main path and adjacent grid point amplitude information, QLS is used to fit continuous domain peak position, and grid mismatch error is corrected.The method breaks through the limitation of physical bandwidth and sampling grid, and realizes nanosecond-level high-precision time synchronization in complex non-line-of-sight environment with very low computational complexity.

This invention discloses a method for estimating LFM pulse signal parameters under aliasing conditions, applied in the field of radar technology. Addressing the problem of aliasing in the time-frequency domain of direct-arrival wave signals from multiple external radiation sources with similar parameters, this invention utilizes fractional Fourier transform to accumulate energy in the direct-arrival wave signal. Based on the analytical expression of the peak-to-peak linear frequency modulated (LFM) pulse signal obtained after accumulation and its fractional Fourier transform, a multi-channel signal is constructed. Finally, using the constructed multi-channel signal, the LFM pulse signal is de-aliased in the fractional Fourier transform domain through blind source separation, ultimately improving the signal-to-noise ratio and separating different pulse signals with similar parameters, thereby achieving accurate parameter estimation. The process of this invention can be implemented using the fast fractional Fourier transform method, which is beneficial for engineering implementation.

The application discloses a method for extracting and correcting the time difference of synchronous seismic data collection while digging, which comprises the following steps: 1, establishing a seismic data collection system while digging, reading all seismic wave data in the collection system and filtering; 2, performing velocity analysis on the filtered seismic wave to obtain the propagation velocity of the seismic direct wave while digging; 3, using the seismic wave propagation velocity original data to correct the direct wave time difference of each seismic trace, and eliminating the influence of the seismic wave propagation time difference; 4, calculating the model trace data of each collection substation through the data after the time difference correction; 5, determining the reference substation according to the model trace data of each collection substation and the data of each seismic trace in the corresponding collection substation; and 6, calculating the time difference of the corresponding collection substation according to the cross-correlation time difference between the model trace of the reference substation and the model trace of each collection substation, and correcting the original data.

This invention belongs to the field of seismic exploration, specifically relating to a method for calculating minimum offset and delay based on direct waves and seafloor reflected waves. The method includes: selecting single-shot seismic data from a flat seafloor location, picking the direct wave travel time, and picking the seafloor reflected travel time of the first data trace at the single-shot location; performing regression fitting on the picked direct wave travel time to fit the direct wave equation, and obtaining the seawater velocity and initial minimum offset based on the direct wave equation; setting an initial delay time range, and calculating the seafloor depth h for each seismic trace at different delay times based on the seawater velocity, initial minimum offset, and seafloor reflected travel time; calculating the 2h variance based on the seafloor depth of the seismic trace, and obtaining the minimum offset and delay time. This invention can quickly obtain the minimum offset and delay time, achieving accurate positioning of seismic data, and the method is simple and easy to implement.

Signal processing equipment, comprising: a map generation unit (13) to acquire a received signal of a reflected wave from a receiving unit which receives the reflected wave from an object located in the vicinity of a mobile object, and to generate a distance Doppler map which indicates a signal strength level of the received signal; an altitude standard deviation calculation unit (15) to calculate a standard deviation of an altitude at which the object is located, based on the distance Doppler map generated by the map generation unit (13); a distance interval calculation unit (14) to calculate a distance interval where a direct wave from the object contained in the reflected wave and a multipath wave from the object contained in the reflected wave interfere with each other, based on a distance Doppler map generated by the map generation unit (13); and a collision determination unit (17, 18) to determine whether or not the object is at a height where there is a possibility of collision between the mobile object and the object, based on the standard deviation calculated by the height standard deviation calculation unit (15) and the distance interval calculated by the distance interval calculation unit (14).

The invention discloses a single hydrophone orientation device and method based on an acoustic metamaterial, and relates to an underwater acoustic engineering technology. By designing a three-dimensional geometric structure and utilizing an acoustic metamaterial to construct an auxiliary device, the orientation of an incident sound wave is determined based on a single hydrophone; the device comprises a honeycomb-shaped cylindrical base and a wedge-shaped acoustic grating group which are distributed asymmetrically; the honeycomb-shaped cylindrical base is divided into N grids, the sound grids in the wedge-shaped sound grid set are fixed to the grids in a one-to-one correspondence mode, and the lengths of the internal coiling structures of the sound grids are arranged in a differentiated mode. The direct wave time and the acoustic grating wave time received by the scalar hydrophone are extracted, the time difference is calculated to reversely deduce the propagation distance increment, and the length of the acoustic grating coiling structure is matched to determine the sound source orientation. The device is simple in structure, low in cost and easy to manufacture and install, can be used for transformation of an existing scalar hydrophone, enables the scalar hydrophone to have an orientation function, improves the detection capability of a single hydrophone, and has important application value for a detection system and a mobile platform deployed in a large range.

The present application relates to a reinforced concrete defect positioning method and system based on ground penetrating radar feature fusion, belonging to the technical field of structure nondestructive testing and ground penetrating radar signal processing. The method comprises: obtaining the original ground penetrating radar B-scan image of the reinforced concrete structure, removing the direct wave by Radon transform, and combining Curvelet multi-scale directional decomposition, adaptive threshold and region of interest constraint to suppress the steel clutter, to obtain a clutter suppression image; calculating the pixel-by-pixel absolute difference value of the original gray image and the clutter suppression image to obtain a clutter image; constructing the original gray image, the clutter suppression image and the clutter image into a pseudo-color three-channel fusion image and inputting the target detection network, and outputting the defect category, the boundary box and the actual physical coordinates. The present application can improve the detection and positioning performance of the hollow, honeycomb and delamination defects in the reinforced concrete under complex steel environment.

The invention provides a high-resolution seismic exploration travel time tomography method and device, and relates to the technical field of seismic exploration, and the method comprises the steps: obtaining shot gather data of a target region; according to the shot gather data, through combination of direct wave travel time and reflected wave travel time, speed model and reflection interface shape synchronous joint inversion is carried out on a first preset number of reflection interfaces with different depths in sequence, and a target imaging result of the target area is obtained; wherein when inversion of the reflection interface of the current layer is carried out, the shape and the speed model of the reflection interface which completes inversion above the reflection interface of the current layer are fixed. According to the characteristics of a multi-reflection layer geologic structure, synchronous joint inversion of the speed model and the reflection interface shape is carried out on the multi-reflection interface layer by layer by combining the direct wave travel time and the reflection wave travel time, and the reflection interface shape and the speed model which are subjected to inversion are fixed in the inversion process, so that the inversion resolution and the imaging stability are effectively improved.

The invention discloses an interference suppression method, and particularly relates to a clutter interference suppression method based on sub-band processing, and the method comprises the following steps: S1, receiving a monitoring signal containing a target reflection echo, a direct wave and a clutter, and a relatively pure direct wave reference signal; s2, respectively converting the monitoring signal and the reference signal from a time domain to a frequency domain; s3, uniformly dividing the converted frequency domain monitoring signal and the converted frequency domain reference signal into a plurality of sub-bands respectively; s4, in each sub-band, performing clutter suppression processing on the sub-band monitoring signal based on the sub-band reference signal so as to eliminate clutter components related to the reference signal and retain a moving target signal; s5, synthesizing all the signals after sub-band processing according to a frequency band sequence to obtain a monitoring signal after full-band clutter suppression; and S6, performing coherent processing on the synthesized monitoring signal and the reference signal to realize target detection and parameter estimation.

The invention discloses a time sequence generation and phase calibration method for a cooperative external radiation source radar system, and belongs to the field of radar signal processing, and the method comprises the steps: receiving a direct wave signal from a transmitting station in the cooperative external radiation source radar system, and determining a direct wave pulse pressure peak value position of a current PRT; when the last PRT of the current CPI is not reached, the sampling starting time of the next PRT is determined by utilizing the direct wave pulse pressure peak value position so as to sample echo data, the echo data are returned and processed continuously until echo signals of the whole CPI are obtained, and a fast-slow time dimension two-dimensional matrix is reconstructed; performing pulse compression on each PRT along a fast time dimension to obtain a fast-slow time dimension two-dimensional matrix after pulse compression; a smoothed phase sequence is obtained by extracting the maximum peak phase of each PRT; and compensating the phase difference of each PRT by taking the first PRT as a reference so as to finish phase correction. According to the invention, system inconsistency caused by asynchronous clock sources between double bases can be corrected.

The invention discloses a rapid inversion method based on a radar electromagnetic model in a high-cold and high-altitude geological environment, and the core idea of the method is that a two-parameter wave field forward modeling model is constructed based on a Maxwell electromagnetic field equation, a time window-based convolution type objective function is utilized, and a real source function is not needed. Source-independent full-waveform inversion of single-offset GPR data is realized, an SVD method is introduced to automatically extract a reference waveform and determine the length of a time window, direct wave and reflected wave information is effectively separated, and the inversion calculation overhead is remarkably reduced in cooperation with a multi-scale frequency and random sub-source sampling strategy. According to the method, high-precision reconstruction can be performed on the underground dielectric constant and the conductivity on the premise that accurate source waveforms are not needed, and the practicability and the real-time performance of plateau area non-contact radar detection are remarkably improved.

The application provides a radio interference source automatic positioning and troubleshooting system and method thereof, the radio interference source automatic positioning and troubleshooting system comprises a front-end hardware enhancement module, a core algorithm optimization module and a system-level cooperative positioning module, the radio interference source automatic positioning and troubleshooting method comprises hardware deployment and preprocessing, spatial domain beamforming and subarray combination, digital domain multipath elimination and signal recovery and the like, the radio interference source automatic positioning and troubleshooting system and method thereof provided by the application effectively solve the problem that the traditional equipment cannot distinguish the direct wave from the reflected wave, so that the direction finding result is seriously deviated or even points to the wrong direction, and greatly improve the accuracy and reliability of the direct wave identification of the signal.

The application provides a ground penetrating radar image stratum horizon correction method, a computer device and a storage medium, and the method comprises the following steps: adopting a ground penetrating radar to perform circumferential detection on a tunnel to-be-detected region to obtain radar atlas data; using a tunnel scanner to scan and position a tunnel section survey line to obtain tunnel three-dimensional point cloud data; constructing a circumferential curved surface model matched with a ground penetrating radar detection path, extracting the center coordinates, the circumferential radius and the detection angle of each detection position of the ground penetrating radar; obtaining the direct wave time of a single-channel radar wave and the stratum interface reflection wave time in the radar atlas data, and calculating the stratum interface burial depth of each detection position; and based on the center coordinates, the circumferential radius and the detection angle corresponding to each detection position, performing geometric correction on the stratum interface burial depth to obtain the actual interface depth of each detection position relative to the tunnel reference surface. By using the application, the stratum horizon deformation during circumferential detection can be eliminated, and the burial depth and strike of the stratum are more intuitive.

The application provides a three-dimensional ground penetrating radar underground cavity target automatic identification method based on a joint CNN. The obtained ground penetrating radar echo image of the underground cavity target is subjected to direct wave removal and gain control to obtain a processed ground penetrating radar echo image; pre-screening is performed, the pixel positions of the cavity targets are marked, a two-dimensional detection data set is prepared, and a three-dimensional detection data set is obtained by repeatedly intercepting a fixed position of two-dimensional images of different channels; the two-dimensional detection data set is randomly divided into a training set and a verification set, RetinaNet networks and Faster R-CNN networks with different backbone networks are used for training of the two-dimensional data set, and a two-dimensional weight model is obtained; the three-dimensional detection data set is randomly divided into a training set and a verification set, ResNet and Res2Net classification networks are used for training of the three-dimensional data set, and a three-dimensional weight model is obtained; the two-dimensional weight model is detected by using the verification set of the two-dimensional detection data set to narrow the target range, then three-dimensional data of the detection position is intercepted from the three-dimensional data set according to the two-dimensional detection result, and the three-dimensional weight model is used for identification. The application solves the problem of low efficiency of traditional methods and two-dimensional neural network recognition of underground cavity targets.

The present application relates to a kind of underwater multi-target tracking methods, comprising the following steps: establishing three-dimensional space coordinate system, obtaining the coordinate of sensor, monitoring water volume, water surface in the coordinate Z2 of Z axis, the coordinate Z3 of water bottom in the Z axis, clutter density λ;Sensor periodically obtains measurement information, the measurement information includes azimuth, elevation and the time delay between direct wave, the set of measurement information in the i frame is recorded as Z (i), the number of measurement information that sensor obtains single target is L;Randomly generate K in monitoring water volume Virtual target c K =[c1,c2,...,c K ] In prior formula, the possibility that a measurement information comes from certain propagation path is expressed;According to log likelihood ratio, establish underwater target model;According to underwater target model, the actual target number and the optimal coordinate of each actual target are obtained. Efficiently positioning and tracking underwater multi-target can be carried out.

This invention discloses a drone swarm presence monitoring system and method based on broadcast signal reflection, relating to the field of drone monitoring technology. It includes multiple receiving and sensing nodes, a data transmission network, a time synchronization unit, and a central processing unit. Each receiving and sensing node includes an observation receiving channel, a reference receiving channel, and an acquisition and local processing module, used to receive FM broadcast signals and extract the characteristics of intensity and phase changes over time to form a sensing feature vector. The central processing unit includes a reference coherence correction module, a background feature learning module, an existence determination module, and an alarm and recording module. It suppresses background drift caused by multipath and environmental noise through phase correction or coherent cancellation based on a direct wave reference, establishes a background feature vector, and compares it with a real-time feature vector to determine the presence of the drone swarm and output an alarm. It utilizes existing broadcast signals as an illumination source to enhance the detection capability of low-altitude, slow-moving, small-sized drone swarms.

The purpose of the present invention is to provide an information processing device capable of estimating communication quality in a mine with a small amount of computation and with relatively high accuracy. This information processing device is provided with: a storage unit that stores topographic information (300) indicating the topography of a mine, position information indicating the position of a transmission station that transmits radio waves, and wireless communication parameters pertaining to wireless communication between the transmission station and a reception station; and a calculation unit that uses the topographic information (300), the position information, and the wireless communication parameters to generate a direct wave power map (312) that indicates the received power of a direct wave among the radio waves transmitted from the transmission station at each location in the mine. The calculation unit corrects the received power (331) at each location in the direct wave power map (312) on the basis of the difference in distance between the location in the direct wave power map (312) and one or more peripheral locations in the periphery of the location and the received power at the peripheral locations in the direct wave power map (referring to Figure 3).

The present application relates to a kind of well seismic signal-noise superposition wave field high-dimensional multi-component feature intelligent separation method, belong to geophysical oil and gas resource exploration field.Establish time-domain multi-component decomposition result serves different dimension differentiation characteristic property expression;Six-dimensional characteristic attribute space based on multi-component signal-noise component is established, and the mathematical characteristics of complex signal wave and multiple types of noise in DAS record, such as direct wave and reflected wave, are revealed;Dual-stage highly integrated framework with tree model as base learner is set up to complete the feature point category determination separation task in high-dimensional attribute space, so as to accurately and efficiently realize low-damage preservation of signal wave field and maximum suppression of noise wave field.The method is flexible, accurately preserves the amplitude characteristics and frequency energy components of DAS two-dimensional exploration record signal field in well, the mathematical basis is reliable and reliable, and the feature is strongly interpretable, which provides an important basis for thin and fine layer detection, oil and gas reservoir exploitation and other practical applications.

The invention provides a method for constructing a bistatic sonar self-interference signal simulation platform in a time-varying marine environment, and solves the technical problems of high cost, long period and high safety risk due to the fact that an existing marine field test is easily influenced by weather and sea conditions. The method comprises the following steps: constructing a three-dimensional dynamic sea surface, an interface scattering model and a sea surface bubble model, respectively calculating interface scattering intensity and bubble cloud scattering intensity, constructing a unit scattering model, and performing unit division on a scatterer of the sea surface of the seabed to obtain a reverberation time sequence; constructing an ocean noise model and a target scattering characteristic model; and constructing a channel structure, correcting a time-varying channel by adopting a path management method to obtain a direct wave signal and a target echo signal, and superposing the direct wave signal, the target echo signal, the reverberation time sequence and the ocean noise model to obtain a receiving signal of a receiving station of the bistatic sonar target detection system. The method can be widely applied to the technical field of underwater acoustic engineering.

The invention discloses an equivalent radiation power test method and device based on multipath separation, and a medium. The equivalent radiation power test method comprises the following steps: S1, establishing a received signal model; s2, determining an impulse response function of a matched filter; s3, determining a linear frequency modulation signal bandwidth; s4, performing matched filtering on the received signal; and S5, equivalent radiation power measurement: after time domain separation of the direct wave and each multipath signal is realized through S1 to S4, the direct wave signal power of a receiving end can be detected, a power calibration table of source signals with different powers after matched filtering is established, the signal power before matched filtering can be obtained by querying the calibration table, and the equivalent radiation power of the receiving end can be obtained. And calculating ERP (equivalent radiation power) in combination with the spatial radio frequency link. The technical problem that the equivalent radiation power test precision is not high due to the multipath effect under the ground open site condition at present is solved.

The invention discloses a multi-base passive radar weak target detection method based on multi-channel space-time joint accumulation, and relates to the technical field of radar communication, and the method comprises the steps: constructing a multi-base passive radar system observation model, obtaining a direct wave signal and an echo signal, and carrying out the sampling and preprocessing of the direct wave signal and the echo signal; constructing a target detector, and updating the target detector into a simplified form expressed by the target motion parameters to obtain a first target detector; processing the first target detector by adopting a signal framing processing mode to obtain a second target detector; and processing and solving the second target detector by adopting a standard discretization mapping mode so as to realize detection of the weak target and obtain an estimation parameter of the weak target. According to the method, on the premise of ensuring relatively low calculation complexity, efficient collaborative accumulation of multi-channel signals is realized, and the detection performance of the system in a low signal-to-noise ratio and high maneuvering target environment is improved.