31 results about "Acoustical oceanography" patented technology

The invention discloses an acoustic real-time detection method for ocean internal waves based on line spectrum identification. A propeller with a set rotating speed is used as a sound source, a standard hydrophone 8301 is used for passive acquisition of propeller noise, and real-time detection of ocean internal waves can be realized based on a propeller line spectrum identification algorithm and in combination with physical features of ocean acoustic. The method comprises the steps of: transmitting propeller noise to a standard hydrophone fixed to seabed through the propeller with the set rotating speed, obtaining an envelope value by performing band-pass and low-pass filtering on acquired signals, extracting a demon spectrum to complete the line spectrum identification; comparing with theset propeller rotating speed, tracking continuously, performing secondary identification when abnormal jumping is discovered, and detecting and alarming in real-time. The steps of the method are simple, the propeller is taken as a sound source, cost is low; the method is suitable for any water area, and has a wide application value.

The invention relates to a parallel coupled ocean acoustic forecasting system and operation method, which belong to the field of physical ocean and underwater acoustic field modeling integration, and the system includes an ocean environment forecast module, an ocean-acoustic coupling module, and an ocean acoustic propagation solution module; The environmental forecast module provides initial environment input for the system; the functions of the ocean-acoustic coupling module include parameter initialization, terrain extraction, and marine environment parameter profile extraction, by outputting parameters including temperature, salinity, and sea surface roughness from the ocean module It is transformed into the input of the acoustic model, combining the ocean model and the acoustic model; the role of the ocean acoustic propagation solution module is the calculation of the ocean acoustic field, the output of the results including the ocean acoustic field and the sonar range. The system realizes the real-time prediction of the underwater sound field, and can be transplanted to any high-performance computer system to quickly realize the accurate calculation of the three-dimensional sound field and the estimation of the sonar range in the global sea.

An exemplary embodiment of the invention relates to a method and system for displaying simulated acoustically realistic active sonar signals. The method includes simulating a realistic sounding active sonar signal that originates from a simulated sonar transmitter. The simulated sonar signal is acted upon and modified by simulated ocean effects and is received by a simulated hydrophone. The sonar signal is acoustically displayed within a simulated ocean acoustic environment that incorporates realistic sounding simulated reverberation.

The invention belongs to the technical field of marine acoustics application of three-dimensional temperature, salt and depth data, and in particular relates to a high-resolution sound velocity profile data compression method based on empirical orthogonal function decomposition, specifically as follows: provide data with high-resolution ocean reanalysis products, and use the sound velocity formula Convert and obtain the seawater sound velocity profile data; according to the characteristics of the marine acoustics application technology field, extend the high-resolution and long-term sequence sound velocity profile data in a certain space-time dimension to the seabed sediment layer; use the eigenvector of the main mode as the sound velocity profile The basis function of empirical orthogonal function decomposition, which compresses and expresses the high-resolution and long-term sequence sound velocity profile information in a certain space-time dimension. The present invention realizes the technical scheme of obtaining sound velocity profile data compression starting from high-resolution ocean reanalysis products; realizes effective compression of sound velocity profile data in a certain space-time dimension, and obtains high-resolution, long-time sequence sound velocity profile data compression rate More than 90% beneficial effect.

The invention relates to the technical field of marine acoustics, in particular to a method for calculating forward acoustic scattering Doppler frequency shifts of moving targets in water. The method for calculating the forward acoustic scattering Doppler frequency shift of a moving target in water with irregular trajectories includes: (1) Converting the earth's latitude and longitude coordinates of the transmitter, target trajectory and receiver into rectangular coordinates, and marking them as (x) S ,y S ), (x T ,y T ) and (x R ,y R ); (2) record the target trajectory coordinate sequence as (x T (t i ),y T (t i )), i=1,2,...,N, calculate the average speed in all time periods (3) Smooth the target trajectory to obtain a virtual straight line trajectory, respectively calculate the distance between the target and the receiving end to the intersection of its virtual straight line trajectory and the baseline Horizontal distance, the angle between the virtual straight line trajectory and the baseline; (4) Using the parameters calculated in steps (2) and (3), calculate the forward acoustic scattering Doppler frequency shift of the target at each moment. The invention solves the problem that the prior art cannot calculate the forward acoustic scattering Doppler frequency shift when the target movement track is irregular.