12 results about "Sonar signal processing" patented technology

The invention discloses a fluctuating background adaptive estimation method under active sonar multi-clutter strong interference, and belongs to the field of active sonar underwater acoustic signal processing. According to the method, backgrounds are respectively estimated through the left eccentric analysis window and the right eccentric analysis window, then the smaller value is taken as the interference background estimation value near the position of the target, and then the signal-to-interference ratio is calculated, so that the risk that a weak target is masked by neighbor strong interference can be avoided or reduced. The method provided by the invention can be used for estimating the uneven background in active sonar application, in particular to self-adaptive estimation of the uneven background in the presence of multi-clutter strong interference. The signal-to-noise ratio of the target can be directly obtained according to the estimated dynamic background, and a basis is established for target detection and positioning. Adaptive estimation of the fluctuating background under multi-clutter strong interference is a necessary preposed link of active sonar signal processing and has an important footstone position.

The embodiment of the invention provides a broadband Doppler sonar signal processing method and system, and belongs to the technical field of signals. The method comprises the following steps: receiving echo signals after the broadband Doppler sonar transmits a plurality of pulse signals; performing frequency shift estimation on a single pulse of the echo signal to obtain a frequency shift interval; performing inter-pulse frequency calculation on the echo signal to obtain an average frequency of a single beam channel; performing frequency shift value calculation according to the average frequency and the frequency shift interval to obtain an echo offset value of a single beam channel; and performing speed calculation according to the echo offset values of the plurality of beam channels to obtain the three-dimensional speed of the measured target. According to the embodiment of the invention, the speed measurement precision of the broadband Doppler sonar under the shallow water condition can be improved.

The present application relates to underwater acoustic engineering, sonar signal processing and harmonic detection technical field, especially a kind of jammer equipment identification method based on retransmission harmonic feature, first the active sonar echo signal obtained is carried out matching filtering and sampling, then using cepstrum algorithm to extract its corresponding cepstrum, finally the obtained cepstrum is detected without direct current component, whether the target is jammer equipment is judged by the ratio of non-direct current component and noise energy.The present application utilizes the retransmission mechanism of underwater decoy target, exposes its harmonic signal characteristics through matching filtering, and on this basis, relies on harmonic signal identification means to identify and eliminate it.The present application effectively improves the identification ability of jammer equipment, and the algorithm process is simple, the calculation complexity is low, the portability is strong, provides an important component module for constructing the detection and identification system of underwater target.

This invention belongs to the field of sonar signal processing and proposes an underwater sonar multi-harmonic micro-Doppler feature recognition technology based on CAMobileNetV2. This technology establishes a micro-echo model of underwater vehicle propeller blades, employs a combined multi-harmonic signal transmission signal, and utilizes time-frequency analysis methods to obtain the micro-Doppler features of blades with different numbers and rotational speeds. To more accurately identify and perceive different types of propellers, this invention constructs a CAMobileNetV2 model combining CBAM (Convolutional Block Attention Module) and MobileNetV2. This model can effectively analyze and extract the micro-Doppler features of the propeller, thereby achieving the identification of different underwater vehicles. Training and testing on the constructed dataset demonstrate the effectiveness and robustness of this technology in underwater sonar signal processing and underwater target recognition. This invention provides a micro-Doppler feature recognition technique in the field of underwater sonar signal processing, which is beneficial for improving the target recognition capability of underwater sonar.

The invention discloses a mixed subspace adaptive Riemannian gradient descent target detection method, and belongs to the technical field of underwater sonar signal processing and intelligent sensing. The method comprises the following steps: firstly, constructing a mixed low-rank subspace and heterovariance noise model, and modeling a background into a union set of a plurality of subspaces; then, calculating the posterior responsibility degree of observation data belonging to each subspace mode by using a soft distribution mechanism of temperature control; thirdly, based on a noise variance contour of online learning, a sparse foreground signal is accurately recovered by adopting a weighted soft threshold operator; and finally, introducing an adaptive gain control strategy, updating the subspace basis matrix on line through Riemannian gradient descent, and dynamically adjusting noise parameters. The method has the advantages of being high in heterovariance noise robustness, capable of automatically adapting to abrupt change of the background environment, high in detection precision and the like, and is suitable for real-time detection and tracking of underwater sonar small targets.

The invention discloses detection and identification integrated sonar signal processing hardware equipment based on a mercuric chloride processor and a use method of the detection and identification integrated sonar signal processing hardware equipment. The detection and identification integrated sonar signal processing hardware equipment based on the mercuric chloride processor comprises an intelligent signal processing subsystem and a sonar front-end subsystem, wherein the sonar front-end subsystem comprises a sonar signal transmitting module and a sonar signal acquisition module, and is responsible for responding to a PWM control signal to carry out high-voltage excitation transmission and carrying out high-speed acquisition and transmission on an echo signal in a DMA mode through a PCIe interface; the intelligent signal processing subsystem takes a mercuric chloride AI processor as a core, and is responsible for directly generating an emission control signal, executing beam forming based on a sparse weighting matrix, and identifying a sonar image target based on a dual-network model. According to the invention, the problems of complex hardware link and high external dependence of the traditional architecture are effectively solved, the computing power utilization rate and the integration level of the system are effectively improved, and the system is suitable for being applied to light-weight and intelligent underwater detection equipment in the future.

The application discloses a point cloud data filtering method based on an AI model, and belongs to the technical field of sonar signal processing and point cloud data analysis; first, original sonar data is collected to generate standardized sonar point cloud data; according to the point cloud space density and distribution characteristics, a self-adaptive space block algorithm is used to divide multiple local observation domains; based on the acoustic reflection physical characteristics, a multi-channel linear normalization mapping algorithm is used to real-time render three-dimensional geometric characteristics and acoustic properties into a two-dimensional acoustic feature image; a convolutional neural network with channel and space attention mechanisms is constructed to perform end-to-end detection on the abnormalities in the image; and the detected initial abnormal points are mapped back to the three-dimensional point cloud space; finally, the abnormal probability score of the initial abnormal points is calculated, and the final abnormal points are removed; the application converts acoustic physical properties into visual features, combines a double attention mechanism and two-stage screening, and realizes high-precision and high-efficiency filtering of complex noises such as transducer interference and multipath effects.

The invention discloses a modularly combinable multi-task sonar signal processing system, method and device and a medium, and relates to the technical field of sonar signal processing, the system comprises a data access layer used for selectively receiving sonar data of a multi-source device through a communication interface; and / or optionally calling different types of data reading functions to read off-line data files of the marine environment data; the sonar signal processing algorithm layer comprises a sonar signal processing algorithm library and is used for storing and managing a plurality of standardized underwater acoustic signal processing basic algorithm functions; the underwater acoustic signal processing basic algorithm function is stored, newly added, deleted and / or called in the form of a dynamic library file; and the multi-task module combination layer comprises a multi-task sonar signal processing flow configuration container and is used for visually calling and combining the underwater acoustic signal processing basic algorithm functions so as to build and execute a sonar signal processing task flow in a self-defined manner. The flexibility and the expandability of the sonar signal processing system are improved.

The present application relates to the technical field of sonar signal processing, and in particular to a passive multi-beam narrowband detection method under the influence of near-field suppression type strong interference, which realizes the estimation of the distance and azimuth of strong interference by multi-scale focusing distance scanning and conventional beam forming with low computational complexity, thereby realizing the correction of the near-field model; in combination with a tolerant interference suppression method, the strong interference can be effectively suppressed by using the corrected focusing steering vector, and the present application can well suppress the influence of near-field strong interference and effectively improve the narrowband target detection performance of passive sonar in a near-field strong interference environment.

The present application relates to the technical field of sonar signal processing, and particularly relates to a smoothing filtering method based on multi-beam narrow-band warning line integration, which comprises the following steps: (1) obtaining multi-beam narrow-band data; (2) pre-processing the obtained multi-beam narrow-band data, and supplementing data values of a half-beam size before and after the data; (3) converting the multi-beam narrow-band data into projection data through line integration transformation, and performing filtering processing on the projection data in the projection domain; and (4) back-projecting the filtered projection data to obtain reconstructed narrow-band data. After the line integration smoothing filtering of the multi-beam narrow-band data, high-resolution spatial energy spectrum can be obtained.

The invention provides a mixed norm time domain broadband beam forming method under a planar array projection coordinate system, which belongs to the technical field of sonar signal processing, and comprises the following steps: calculating the expected frequency response of a finite impulse response filter according to a conventional beam forming weight, and carrying out pre-delay processing on a received signal to obtain a mixed norm time domain broadband beam; a mixed norm constraint criterion is adopted to carry out two-norm constraint on a pass band and infinite norm constraint on a stop band, a finite impulse response filter optimization target and constraint conditions are established, a convex optimization solver is utilized to solve a time domain impulse response of a finite impulse response filter, and after a received echo signal passes through the finite impulse response filter, the finite impulse response is obtained. The problems that when array element time delay is calculated in planar array broadband beam forming, due to the fact that a spherical coordinate system is adopted, an azimuth angle and a pitch angle are in a product relation, time delay calculation complexity is high, and beam forming performance is reduced due to the fact that constraints of a pass band and a stop band are unbalanced in the design of a filter are solved.