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System includes main and additional noise direction-finding paths, a hydroacoustic signal detection path, a sonar path, a communication and recognition path, a mine and navigation obstacle detection path, a central computing system, a display, recording, documenting and control system and a common bus. All radiating antennae of the sonar path are electronically controlled on both the number of directional pattern beams and the width and direction thereof. The main noise direction-finding path comprises a main front receiving antenna and a first preprocessing device. The hydroacoustic signal detection path comprises three receiving antennae and a second preprocessing device. The sonar path comprises three electrically controlled antennae and a first generator device. The communication and recognition path comprises two radiating antennae and a second generator device. The mine and navigation obstacle detection path comprises a transceiving antenna, a "receive-transmit" switch, a third generator device and a third preprocessing device. The additional noise direction-finding path comprises a flexible extended trailing antenna, a conducting rope, a current collector and a fourth preprocessing device. |
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Acoustic sounder of pulsed sound sources Invention can be used to measure a sound source (SS) distance from an acoustic locator, its corrected sound-ranging angle and topographic coordinates (TC) of this SS. It comprises left (LLG) and right linear groups (RLG) of sound locators (SL); each group mentioned above consists of 3 SLs. Centres of these LGs are frontally arranged at approximately several hundred metres from each other and at approximately several kilometres from a troop confrontation line; there are also provided three signal processing channels (SPC), a computer (C), a selector pulse formation chain (SPFC) and a SL LG directional characteristics control system enabling signal processing in the SPC at certain moments only as determined by programs installed in 2 of its microconvertors that improves a noise immunity of the acoustic locator and provides obtaining the TCs of the SS found in a sector of reconnaissance. The first SPC and a frequency channel consist of a signal extractor (SE), a voltage summator (VS), an amplitude detector (AD), an analogue-to-digital convertor, and a series register connected to the computer. The second SPC comprises an SE, a VS, an AD, a time measurement system (TMS) and 2 registers connected to the computer. The TMS measures a pulse count (at a repetition cycle of 1 ms) to the moment of pulse acoustic signal receipt by the RLG of the SL, as well as to the LLG of the SL; the SPFC comprises series connected frontal SL, a Schmitt trigger and a trigger circuit. The frequency f1 channel processes an electrical signal of the frequency f1, while first and second ones - of the frequency f0. Processing the signals in the first SPC and the frequency f1 channel results in computed calculation of distance to the SS, while processing the signals in the second SPC results in computed measurement of the corrected sound-ranging angle, the TCs of the SS. |
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Device for detecting signals and determining direction of source thereof In said device, detector response is generated without the effect of the average value of spatial response of the detector on interference and the possibility of receivers of a discrete antenna array to move in space under external forces is taken into account. To this end, the detector has a discrete antenna array (DAA) made in a certain manner, having N non-directional passive and M active-passive electroacoustic transducers, corresponding I information transmission channels, a beam pattern control unit, a unit for calculating relative coordinates of DAA elements, a threshold device, a decision threshold computer, a display, a unit for controlling active-passive DAA elements, as well as a beam pattern former with signal time delay. The fundamental differences between the invention and the prototype lie in that the detector includes an operator panel and the beam pattern former further includes a microprocessor unit capable of subtracting, using a subtractor, the average value of the detector response to interference only from the output signal of a storage device. |
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Method of measuring change in course angle of probing signal source Method of measuring change in the course angle of a probing signal source involves successively receiving probing signals of a moving source; spectral analysis of the first, second and n-th received signals; in each of said received signals, determining the detection threshold, change in amplitude of spectral readings exceeding the threshold; determining and storing values of spectral readings F1, F2 and Fn, having maximum amplitude; calculating the difference between values of spectral readings F2-F1 and Fn-F1; and the value of change in the course angle of the probing signal source Q n 0 is defined as a r cos Q n 0 , where C o s Q n 0 = ( F n − F 1 ) / ( F 2 − F 1 ) < 1, if the angle between the receiver and the source of probing signals increases, or C o s Q n 0 = ( F 2 − F 1 ) / ( F n − F 1 ) < 1, if the angle between the receiver and source of probing signals decreases; and if (Fn-F1)(F2-F1)=1, the course angle has not changed or has changed slightly. |
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Invention relates to hydroacoustics. The method of determining the direction of a hydroacoustic transponder in multibeam navigation signal propagation conditions involves determining direction simultaneously in horizontal and vertical planes towards a hydroacoustic transponder by receiving the transponder signal using an antenna array, amplifying the received signal with preamplifiers connected to the output of each converter of the antenna array and digitising with sampling frequency Fs. The transponder emits, in response to a request of a hydroacoustic navigation system, a composite navigation signal at carrier frequency, subjected to phase-shift keying according to a Gold code sequence law; the signal received by each converter of the antenna array is filtered by a digital filter which is matched with the navigation signal, and the duration of the navigation signal is selected such that the greatest Doppler distortion of the navigation signal, which corresponds to the range of possible velocities of the carrier of the antenna array relative a stationary transponder, leads to mismatch of the filter and the received navigation signal. |
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Onboard system and method of shooter location Invention relates to onboard system of shooter detection, including several sensors attached to an aircraft shell, e.g. to a helicopter. Sensors detect only shockwave signals. Signals detected are analyser to locate a shooter with certainty. Analysis may include measurement of arrival time of missile shockwave at each sensor, obtainment of signal arrival time difference, calculation of ambiguous solution set corresponding to the shooter, and clustering the solution set to locate the shooter with certainty. Elliptic cluster is used. |
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Estimating sound source location using particle filtering Invention relates to estimation of the location of a sound source using particle filtering, particularly estimation of the location of a sound source for a multimodal audio-visual communication application. A sound source location is estimated by particle filtering where the particles represent a probability density function for a state variable comprising the sound source location. The method includes determining the weight coefficient for a particle in response to correlation between estimated acoustic transfer functions from the sound source to at least two sound recording positions. A weight coefficient update function may specifically be determined deterministically from the correlation and thus the correlation may be used as a pseudo-likelihood function for the measurement function of the particle filtering. The acoustic transfer functions may be determined from an audio beamforming towards the sound source. The audio weight coefficient may be combined with a video weight coefficient to generate a multimodal particle filtering approach. |
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Technology of confirmed positioning in underwater navigation space of mobile polygon Equipment complex with a system of confirmed 3D positioning with angular alignment of a unit of its information exchange with an object and a unit of source global coordinates according to a GLONASS receiver is introduced into a tested object. At the same time a mobile polygon is complemented with buoy-anchor positions with a submersible container, where an equipment module is placed with a unit of a beacon-responder of the system of confirmed positioning and a unit of demodulation of hydroacoustic telemetric signals. A transmitting (receiving) device of a satellite system, "INMARSAT", and a radio modem are placed into a floating buoy of the anchor position. A receiving (transmitting) device of the satellite system "INMARSAT" is placed on the vessel (coastal) station. |
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Method for passive determination of coordinates of radiation sources Method involves receiving signals with M≥3 antennae; setting up a "direction-range" coordinate grid in display field with the required boundaries and discrete intervals; calculating paired differences in signal propagation time for each node of the coordinate grid; determining (M2-M)/2 paired cross-correlation functions of signals from antenna outputs; quadratic detection of output signals of each antenna; reading out (M2-M)/2 values of the obtained paired cross-correlation functions and summing their doubled value with results of quadratic detection of signals from each antenna, after which all the obtained sum values are output to the coordinate grid of the display, and coordinates of radiation sources are determined from the position of the maximum the indicator values on scales of the coordinate grid. |
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Correlation signal detector has a discrete antenna array (DAA) made in a certain manner, having N non-directional passive and M active-passive electroacoustic transducers, corresponding I information transmission channels, a beam pattern control unit, a unit for calculating relative coordinates of DAA elements, a threshold device, a decision threshold computer, an indicator, a unit for controlling active-passive DAA elements, as well as correlation beam pattern former with signal time delay. The correlation beam pattern former with signal time delay employs I/k squaring devices, outputs of which are connected to corresponding I/k inputs of a squared process adder, where 1≥k>1, and between the I/k squared process adder and a correlation computer, there is an additional multiplier, the input of which is connected to the output of the I/k squared processor adder, and the output of the multiplier is connected to the second input of the correlation computer. |
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Method involves receiving signals using a flat antenna array having M rows of antenna elements lying one above the other, wherein the antenna elements in one row have the same coordinates in the elevation plane; directional angles of maxima of beams are given in the azimuthal θ1…θK and elevation φ1…φK planes; weight coefficients are calculated for each receiving channel in the azimuthal plane and weight coefficients are calculated for each row of antenna elements in the elevation plane, where K is the number of formed beams; synchronous sampling and quantisation of each signal from the output of each antenna element is performed. The series of readings from the output of each digital-to-analogue converter is converted to a series of quadrature readings; filtration and decimation of the repetition frequency is performed K times. For each receiving channel, a series of weighted readings is formed by multiplying each quadrature reading by weight coefficients which correspond to coordinates of beams from the 1st to the K-th in the azimuthal plane. For each m-th row of antenna elements, a series with readings of partial beams of the beam pattern in the azimuthal plane is formed by summing weighted readings of receiving channels of each row, following with period K and associated with identical sampling moments. For each row, a series of weighted readings is formed by multiplying each reading, associated with the k-th beam, by weight coefficients which correspond to coordinates of beams in the elevation plane. The resultant series of readings of K beams of the beam pattern is formed by summing weighted readings of each row associated with the k-th beam associated with identical sampling moments. |
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Invention relates to diving equipment, particularly, to underwater sound communication and direction-finding means used by divers. Diver direction-finder integrated with underwater sound communication station consists of pulse generator and two identical pulse receivers, each being provided with antenna arranged at the left or the right of diver. Outputs of direction-finder receive channels are connected with switchboard which connects diver left or right phones to underwater sound station depending upon antenna receiving pulse generator signals from another diver. |
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Method of estimating distance to shot point Proposed method comprises measuring of both shock and muzzle waves. Note here that signals including the data only of shock wave are measured by acoustic transducers spaced apart to make an antenna to measure signals of muzzle wave by acoustic transducers. Measured signals of shock and muzzle waves are used to estimate the distance to shot point. Initial expected shell velocities and shell drag are set to select the solution in every generation of maximum discrepancy to be a permanent species to allow reiterative computation of shell instant speed in shell flight in preset path to obtain renewed data of the distance to shot point. |
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Method of determining direction of hydroacoustic transponder beacon on horizontal and vertical angle Method involves a ship emitting a request signal and a spatial antenna array receiving a response signal from a transponder beacon; the spatial antenna array is broken into a set of planes such that each plane is formed by acoustic centres of three or four converters lying on two intercrossing lines; each plane is linked to its own Cartesian coordinate system and the horizontal angle and vertical angle of the direction of the signal source is calculated, for which converters whose acoustic centres form said plane are broken into two pairs; the signal is digitised with sampling frequency Fs; a cross-correlation function of signals x1 and x2 is calculated and for each pair of converters, the difference in time of arrival of the plane wave front at the converters is calculated. For each plane, the horizontal A' and vertical E' angle of the direction of the signal source is calculated in the coordinate system O'X'Y'Z' of the corresponding plane. |
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Method of determining torpedo parameters In the method of determining parameters of a torpedo moving on a homing trajectory, involving receiving acoustic signals of the torpedo with a hydroacoustic antenna mounted on observer ship, converting the acoustic signal to an electric signal, pre-amplification and primary processing of the received signal, automatic angle tracking of the torpedo, classifying the received signal and determining motion parameters of the torpedo in a computer, includes further reception of probing radiation signals of the torpedo homing system, determining frequency of the probing signal, duration thereof, tracking period and level; classification results are used to determine parameters of the torpedo homing system - antenna area, level of reception acoustic interference; reflectivity of the observer ship is determined; propagation loss and threshold level of the probing signal Psettl are determined using a sonar equation applied to the torpedo homing system; the current signal level Pt is compared with the threshold signal level Psettl and the moment when the condition Pt≥Psettl is satisfied is defined as the moment of detection of the torpedo by the observer. |
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Result is achieved by integrating inertial, hydroacoustic, hydrostatic and magnetic measurements via digital statistical optimum processing of an excess number of measurements of parameters of movement and positioning of the object to estimate instrument errors, consistence of which is based on equally accurate hydroacoustic measurements for determining global coordinates of hydroacoustic transponder beacons as the positioning object moves from the point of inputting initial values of global coordinates and then determining more precise spatial global coordinates of the positioning object and orientation angles thereof. |
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Hydroacoustic measurement complex comprises N acoustic combined receivers, every of which comprises a hydrophone, a three-component vector receiver and connected amplifiers, a telemetric unit, including voltage dividers, an analogue to digital conversion circuit, a single circuit of electronic multiplexing, a modulator and an optical radiator, connected with an optical communication line with an optical receiver, a system of collection, processing and treatment of information, comprising a unit of information collection, processing and treatment and a device of access to digital circuits of data transmission. By means of acoustic combined receivers, a bottom vertically oriented equidistant antenna is produced, in which the distance between acoustic combined receivers is equal to the specified error of detection of a vertical coordinate (horizon) of the source of sound Δz, a the number of receivers N=H/Δz (where H-sea depth). The information collection, processing and treatment system additionally includes an N-channel unit of calculation of a vertical component of an intensity vector, a unit of determination of a maximum of a vertical intensity vector component, an N- channel unit of calculation of horizontal intensity vector components, an N-channel unit of calculation of an azimuthal unit, a unit of calculation of an averaged azimuthal angle. |
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Diagram-forming device for multipath reception of ultrasound signals Invention relates to field of medical device building, in particular to devices for ultrasound echolocation if internal organs. Device contains receiving-transmitting module, which includes receiving channels of signals from elements of ultrasound sensor, each receiving channel of signals is electrically connected via individual analogue-digital converter with primary random access memory (RAM) of FIFO type, which in its turn is connected with primary filter-interpolator, secondary random access memory of FIFO type. Primary RAM is connected with primary unit of shift registered, outlets of primary filter-interpolator and primary unit of shift registered are connected with respective inlets of two secondary filter-interpolators, said units being connected via secondary inlets of shift registered with respective inlets of beam shapers, each of which is connected with respective adder of channels and includes successively connected multiplexor, secondary RAM and multiplier. Each filter-interpolator represents filter-interpolator with fixed symmetric impulse characteristics and includes shift registers, intermediate adders, multipliers and total adder. In primary filter-interpolator shift registered are combined in one line, and in secondary filter-interpolator shift registers are combined in two lines, one of which is connected with primary unit of shift registers, the other one is connected with primary filter-interpolator. |
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Hydroacoustic system for measuring coordinates of sound source in shallow sea Hydroacoustic measurement system has N composite acoustic receivers, a telemetering unit having voltage dividers, an analogue-to-digital converting circuit, a single electronic multiplexing circuit, a modulator and an optical emitter, a system for collecting, processing and transmitting information and a device for accessing digital data networks. An orthogonal bottom base is formed in the hydroacoustic measurement system by three composite acoustic receivers P1, P2 and P3. Additional composite acoustic receivers and the receiver P1 form a bottom vertically oriented equidistant antenna. The system for collecting, processing and displaying information further includes an (N+1)-channel unit for calculating the vertical component of the intensity vector, a unit for determining the maximum of the vertical component of the intensity vector, an (N+3)-channel unit for calculating horizontal components of the intensity vector, an (N+1)-channel unit for calculating the azimuthal angle, a unit for calculating the averaged azimuthal angle, a unit for calculating the azimuthal angle for composite acoustic receivers P2 and P3 and a unit for determining coordinates of the sound source. |
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Bottom drag-resistant self-contained hydroacoustic module Disclosed is a bottom drag-resistant self-contained hydroacoustic module which is fitted with subsystems and devices which are placed in the housing of the bottom module and on the conducting rope of a vertical hydroacoustic antenna and facilitate operation of the module. On the conducting rope of the hydroacoustic antenna there is a float, hydrophones, a transceiving unit for acoustic underwater communication. In the housing of the bottom part of the module there is a subsystem for collecting and preprocessing information from all sensors mounted on the vertical antenna, a subsystem of geographic coordinates of the module. Drag-resistance of bottom self-contained hydroacoustic module is provided by that the housing of the bottom part of the module consists of two flattened cones. The bottom flattened cone faces the mud line with its large base and the small base is mated with the top flattened cone and has a surface inclination angle of 30-40 degrees. The top flattened cone is mated with the bottom cone by its large base and has a surface inclination angle of 10-20 degrees. |
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Method of measuring levels and horizontal directivity of noise of off-shore oil and gas facilities Method involves, in each cycle of processing hydroacoustic information, receiving a hydroacoustic signal on multiple receiving linear antennae with a developed aperture in the horizontal plane, performing fast Fourier transform over time samples of signals from separate antenna hydrophones and range filtering, as well as static beam pattern fan in the horizontal plane for each of the antennae, frequency-time processing in each spatial channel, squaring, time-averaging, standardising signals and noise, making a decision on detection by comparing with a threshold signal-to-noise ratio. The following operations are successively performed in each cycle of processing hydroacoustic information in addition to the above-mentioned: detecting narrow-band components in spectra of each spatial channel; eliminating the effect of narrow-band components of the spectrum of strong noise sources on the spectra in the spatial channels of the beam pattern fan; identifying local maxima of a priori known fixed noise objects based on known coordinates thereof; estimating the noise spectrum, including the solid part and narrow-band components; comparing the obtained estimates of the levels of readings of the spectrum of noise objects scaled to 1 m, with values of allowable noise levels and generating a feature of exceeding the allowable level with refinement of the frequency and the level of spectrum fragments, where the exceeding of the allowable noise level occurs; selecting spatial channels of the static beam pattern fan of each of the receiving antennae. |
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Device for determining sound source direction Device for determining sound source direction includes two photoelectric shadow instruments, each of which includes in-series installed laser, collimating lens, two pieces of protective glass, focusing lens, beam splitter in the first photoelectric shadow instrument, two knives in the form of semi-planes with mutually perpendicular edges in the first photoelectric shadow instrument, the third knife in the form of a semi-plane in the second shadow instrument, matching lenses installed after each of the above knives, two photoreceivers and two amplifiers in the first shadow instrument and one photoreceiver with an amplifier in the second shadow instrument. A plane parallel plate is installed in each shadow instrument after the laser at an angle of 45° to optic axis. Device also includes two deducting stages, to which amplifiers are connected; outputs of all deducting stages are connected to inputs of their analogue-to-digital converters, the outputs of which are connected to inputs of the devices determining mean square values of signals, the outputs of which are connected to the input of programmed logic integrated circuit; outputs of analogue-to-digital converters are connected to inputs of signal multipliers. |
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Hydroacoustic complex to measure azimuthal angle and horizon of sound source in shallow sea Hydroacoustic measurement complex comprises N acoustic combined receivers, every of which comprises a hydrophone, a three-component vector receiver and connected amplifiers, a telemetric unit including voltage dividers, an analogue-digital transformation circuit, a single circuit of electronic multiplexing, a modulator and an optical radiator, connected with an optical communication line to an optical receiver, a system of information collection, processing and transfer, comprising a unit of information collection, processing and transfer, and a device of access to digital networks of data transfer. N acoustic combined receivers form a bottom vertically oriented equidistant antenna, in which the distance between acoustic combined receives equals to the specified error of detection of a vertical coordinate (horizon) of a sound source Δz, and the number of receivers N=H/Δz (where H-sea depth). The system of information collection, processing and display additionally includes an N-channel unit of calculation of a vertical component of an intensity vector, a unit for detection of maximum of a vertical component of an intensity vector, an N-channel unit for calculation of horizontal components of an intensity vector, an N-channel unit of calculation of an azimuthal unit, a unit to calculate averaged azimuthal angle. |
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Device to detect direction at sound source In a device for detection of a direction at a sound source comprising a photoelectric shadow device and a system of information processing, in a radiating part comprising a laser and a collimating lens, there is a beam splitter installed, which generates a reference channel, signals of which are subtracted with signals of two information channels. In the receiving part comprising a focusing lens and a beam splitter generating two information channels, light beams are focused at edges of knives installed perpendicularly to each other and reacting at variation of a gradient of a refraction (density) index in two mutually perpendicular directions, which makes it possible to indicate light variation proportionally to projections of light spots movement sections in the plane of knives on the axis X and Y, which is information on a direction at a sound source. Further electric signals after amplification and subtraction are digitised, afterwards arrive to two branches of information processing, one of which, comprising two devices that measure mean square deviation, after a divisor produces a tangent Fi, i.e. angle module, and the second branch consisting of a multiplier of instantaneous signals of a device that measures mathematical expectation, and a threshold device with a zero threshold, defines an angle sign, afterwards signals from both branches of information processing arrive to the inlet of the programmed logical integrated circuit, which defines direction at a sound source. |
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Signal of a source is received at two nondirectional antennae, distance between which is equal to λ/4. The signal from the first antenna is transmitted to the input of an adder and the signal from the second antenna is successively delayed by a time from T/4 to 3T/4 and then transmitted to the second input of the adder. As a result of the summation of the signals at different positions of the switch, a set of root-mean-square values of the resultant signal is obtained. Inverse values are then calculated and the maximum of said values is selected. The number of the position of the switch corresponding to the maximum value of the inverse signal is determined, and the introduced delay is determined based on the obtained number. The introduced delay is then used to calculate the angle between the direction of arrival of the signal and the line which connects the centres of the antennae. The obtained angle is converted to voice form and signalled to the diver through headphones. The diver searches the direction where the value of the deviation angle becomes minimum in any plane, and then starts working in the plane which is orthogonal to the one selected before receiving the voice message "deviation is 0 degrees". |
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Hydroacoustic system for measuring azimuthal angle to sound source in shallow sea Hydroacoustic measuring system (HMS) has a bottom orthogonal base which is formed by three acoustic composite receivers, each consisting of a hydrophone, a three-component vector receiver and amplifiers connected thereto. The HMS also includes a telemetric unit, having voltage dividers, an analogue-to-digital converter system, a single electronic multiplexing circuit, a modulator and an optical emitter, connected by an optical link to an optical receiver, an information collection, processing and transmission system having an information collection, processing and transmission unit, a three-channel unit for calculating the vertical component of the intensity vector, a first unit for calculating a signal cross correlation function K12(τ), a second unit for calculating a signal cross correlation function K13(τ), a unit for calculating the maximum of the cross correlation functions, a unit for calculating the azimuthal angle to the sound source relative the X axis. |
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Method of positioning underwater objects Method involves placing acoustic beacons near the coast at a depth 5-10 times greater than the wavelength of the emitted hydroacoustic signal, said acoustic beacons operating in the low-frequency band and emitting composite, primarily phase-shift keyed or frequency-modulated signals with central frequency lower than 10 kHz. Coordinates of the beacons and electronic copies of the signals emitted by said beacons are entered into an on-board system for calculating coordinates of underwater objects. Calculation of coordinates of underwater objects involves an on-board device picking up a useful signal from the acoustic beacons through cross-correlation processing of the received signal with an electronic copy of the emitted signal in real time, wherein for distances shorter than 20 km and shallow sea conditions, the useful arriving first is selected, and for distances greater than 20 km and deep sea conditions, the useful signal arriving last is selected. |
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Method of classifying sonar echo signal In the method of detecting a sonar echo signal, obtained sets of discretised readings undergo spectral analysis; the energy spectrum is determined from each set of discretised electrical signal readings; the average of all spectral readings is determined on each set; the spectral reading with the highest amplitude is calculated on each set; in each set the amplitude of the reading is compared with a threshold, which is selected from the average value; if the amplitude of the reading is greater, the spectral width of the echo signal is determined as the number of readings exceeding the threshold; the highest amplitude of the reading, the value of the spectral reading and the spectral width are stored; the value of spectral readings is compared in the next time sets; the amplitude values of spectral readings are compared in the next time sets; the set with the maximum amplitude is determined; the spectral width of the echo signal is determined for the set with the maximum amplitude; a decision is made in favour of an echo signal from a target if the maximum amplitude values of spectral readings match in neighbouring time sets in the range of ±2 readings, spectral width less than 2/T and the maximum amplitude values of spectral readings in neighbouring sets less than the maximum amplitude of the selected set, and the spectral width of neighbouring sets greater than 2/T; otherwise a decision is made in favour of interference. |
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Invention is based on calculating a continuous wavelet transform of an input process based on a combined complex analytical wavelet whose spectral function matches the spectral power density of the entire sequence of sounds comprising K discrete components (for the biggest possible scale and, consequently, with the lowest possible central frequencies for K discrete components). |
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Hydrolocation system of hydroacoustic station Disclosed system is based on two parts: an active hydrolocation channel and a noise direction-finding channel. The active hydrolocation channel has series-connected probing signal generating device 1, generating device 2 and transmitting antenna 3, series-connected receiving antenna device 4, target echo signal processing device 5 and device 6 for measuring the radial component of the speed of the target, a device 7 for measuring range to the target, a unit 8 for determining angular speed and a unit 9 for more precise definition of the bearing and controlling the position of the antennae of the channel. The noise direction-finding channel has series-connected receiving antenna device 10, noise direction-finding signal processing device 11 and bearing measurement device 12. |
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Acoustic parametric receiver has a high-frequency voltage generator 1 connected to an acoustic transducer 2, which is in acoustic contact through an acoustic waveguide 3, the boundaries of which are transparent for a low-frequency acoustic signal and not transparent for a high-frequency acoustic signal, with a wideband acoustic transducer 4, connected through series-connected selective amplifier 5, phase changer 6, phase detector 7, attenuator 8, with a recorder 9. The second input of the phase detector 7 is connected to the output of the high-frequency voltage generator 1. The broadband acoustic transducer 4 is connected through series-connected resonance amplifier 10 and amplitude detector 11, to the control input of the selective amplifier 5. The output of the phase detector 7 is connected through an integrator 12 to the control input of the phase changer 6. Outputs of the control unit 13 are connected to the control inputs of the high-frequency voltage generator 1, the resonance amplifier 10, the attenuator 8, the recorder 9 and the second control input of the selective amplifier 5. |
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Method of determining bearing of noisy object Method involves receiving an acoustic signal during "electric" rotation of the beam pattern of components x and y of a composite receiver consisting of a vector receiver and a hydrophone. The received signal undergoes analogue-to-digital conversion via Hilbert or Fourier transform with subsequent conversion of the signal into analytical form. Further, the ratio of the imaginary part of the signal to the real part is calculated and that ratio is used to estimate the phase difference between acoustic pressure p(t) and orthogonal components of particle velocity The bearing of the noisy object is identified by a phase difference jump of 180°. |
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Apparatus and method for determining direction of audio source by diver Signal from a source is received at two nondirectional antennae at a distance of λ/4 from each other. The signal from the first antenna is transmitted to the input of an automatic gain control (AGC) amplifier and the signal from the other antenna is delayed by a quarter-period is summed up with the signal from the first antenna. The summation results in formation of a cardioid-type beam pattern. The resultant signal is transmitted to the control input of the AGC amplifier, the gain of which is inversely proportional to the control signal level. As a result, a signal reaches the headphones of the diver, said signal becoming maximum if the diver turns such that the line connecting the right and left side antennae turns in the direction of the source. |
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Apparatus has an analogue-to-digital converter (1) whose output is connected to the input of a recirculator (2). The output of the recirculator is connected to the first input of a discrete wavelet transform computer (3). The wavelet transform output is connected to the input of a fast Fourier transform computer (8), the output of which is connected to the first input of a complex multiplier (9), the output of which is connected to the input of an inverse fast Fourier transform computer (11), the output of which is connected to the input of a squared absolute value computer (12), the output of which is connected to the input of a threshold device (13), the output of which is the output of the apparatus; a control device (14), the outputs of which are connected to control inputs of the analogue-to-digital converter (1), the recirculator (2), the discrete wavelet transform computer (3), a multiplier (5), an inverse discrete wavelet transform computer (7), the fast Fourier transform computer (8), the complex multiplier (9), the inverse fast Fourier transform computer (11) and read-only memory (4, 6, 10). |
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System for determining coordinates of underwater objects Coordinate system is created from GIB buoys with base length of 1-3 km, which receives ping signals of underwater objects, synchronised with GPS clocks and time-spaced. Through correlation reception, the GIB buoys determine lag time from each object and relay these data to a control station. Based on the lag time and data on hydrostatic pressure on the underwater object, the control station calculates coordinates and displays the position of each object. |
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Device to compensate for wave front curvature Proposed device represents adaptive system to allow optimising antenna phase reception of acoustic signals in Fresnel range. For this, proposed device comprises multi-component cylindrical antenna with N receiving channels. It differs from known designs in that it incorporates additionally HF signal generator and HF radiator and allows every preamplifier to switch over to frequency multiplexer mode. Said distinctive features allow heterodyning received useful HF signal and optimising antenna phase reception of acoustic signals with curved wavefront. |
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Method involves generation and emission from a source of a harmonic signal with frequency ω, reception of an acoustic signal using a set of N≥8 hydrophones which form a circular measuring base directed into the horizontal plane, picking up quadrature components of the complex envelope of received acoustic signals, measurement of the phase of acoustic signals, preliminary phasing of the measuring base into N directions passing through the centre of the measuring base and each of the N hydrophones, determination of the direction which corresponds to the maximum of the signal and a hydrophone lying in that direction, calculation of the heading angle to the source in a local coordinate system associated with the measuring base using corresponding formulas. The hydrophone lying in the direction of the signal maximum is taken as the first hydrophone. The mobile subsurface object is also fitted with a pair of hydrophones spaced out in a diametrical plane along the mobile subsurface object at a distance of 1≤λ/4σθ. After calculating the bearing, the heading angle β0 to the source is calculated using formula β0=β1±θ0, σβ0=σβ, where β1 is the heading angle of the first hydrophone of the circular measuring base, the sign (+) is taken for the heading angle of the starboard side, the sign (-) is taken for the heading angle of the port side, σβ0 is the error in determining the heading angle, σθ is the bearing measurement error. The mobile subsurface object then synthesises a beam path on which the condition β0=180°+σθ is satisified, and a traversing path on which the condition β0=±90°+σθ is satisfied. Further, phase difference of acoustic signals Fm received using an extra pair of hydrophones is measured on the traversing path at time moments tm, m=1-M. The values of phase difference of acoustic signals Fm(tm) measured on the acoustic path are approximated with a linear function F=a(t-t0). Parametres a are determined through a least-squares method using corresponding formulas, and the true heading angle to the source at point t=t0 is determined using formula |
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Invention is related to the field of hydroacoustics, namely to devices for detection of narrow-band noise hydroacoustic signals (with spectral density of power in the form of separate discrete components or their scales) at the background of additive noise. Invention is based on calculation of continuous wavelet transformation of input process on the basis of complex analytical wavelet, relative band of amplitude spectrum of which matches relative band of spectral density of detected signal power. Device comprises analog-digital converter (ADC) 1, recirculator 2, the first calculator of fast Fourier transform (FFT) 3, complex multipliers 4.1 - 4.M, scaling devices 5.1 - 5.M, device of complex conjugation 6, device of negative frequencies nulling 7, the second calculator FFT 8, permanent memory (PM) 9, calculators of reverse FFT 10.1 - 10.M, calculator of module square 11, averaging device 12, threshold device 13, control device 14. |
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Method for protection of water barriers Invention is related to hydroacoustics and may be used for protection of objects from the barrier side in water medium. According to method, signal is generated from hydroacoustic antenna arranged in the form of piezoelectric cable sections, ends of which are connected to radio frequency cable with the help of matching devices fed from common source, signal voltage is picked up from loading resistor and is sent through separating capacitor to inlet of alarm signal generator, object parametres are identified by results of analysis of spectral and time variation of signal. |
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Method and system of determining trajectory of supersonic projectile Present invention can be used for determining the trajectory of a supersonic projectile. At least the initial part of signals is measured, containing information only on impact wave, using five or more acoustic sensors, spread out in space such that they form an antenna. From this measured initial part of signals, the difference in arrival time for a pair of sensors is determined. A genetic algorithm is applied to the initial chromosome, which contains initial estimated parameters of the projectile trajectory. For a given number of generations, projection errors are calculated for solutions, obtained from chromosomes from the genetic algorithm. The ratio of solution with the least values of projection errors to the ambiguous solution is calculated, and if this ratio is greater than a given value, the solution with the least value of calculated projection error is chosen as the correct trajectory of the projectile. |
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Method to receive information on sound-producing objects in sea Noise signals are received in horizontal and vertical plane, frequency-time processing is carried out in every spatial channel of observation, output voltages of formed space channels are squared and summed in all frequency samples, then averaged in time, signals are centered and normalized to noise, signal energy and information parameters are accompanied, route detection is carried out by comparison of generalised weight of signal local maximums with threshold of signal detection, which corresponds to threshold ratio of signal-noise. Method is based on the fact that in every cycle of viewing noise signals are received, primarily processed, squared, secondarily processed and route-detected in at least another two frequency ranges and additionally, at least, for two angles of observation in vertical plane, creating new expanded set of space channels. |
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Method of navigational support of autonomous underwater robot controlled from control ship Determined is the starting point for autonomous underwater robots (AUR), taken for the beginning coordinates. Control ship in moved in accordance with the movement of the AUR. Onboard of the AUR the coordinates are determined, which are then controlled by the base hydro-acoustic beacon, on which is additionally added a transmitter of navigational signals which emits navigational signals. Navigational signals are received onboard the AUR, processed and combined with the information signal. Evaluation of the AUR coordinates are obtained by the data of the hydro-acoustic navigation system (HANS), which is made complex, and a deliberate evaluation is made of the coordinates AUR. This data is transmitted with AUR by the hydro-acoustic channel, the base hydro-acoustic beacon is set, then transmitted through a cable link to onboard the control ship and is reflected in real time. |
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Method of sea noisy objects detection Method includes as follows. Horizontal and vertical orientation characteristic static fan receives noise signals in combination with frequency-time processing within each spatial observation channel, quadrating, time averaging, alignment and signal normalising to interference, observation of current view cycle for received normalised signals and detection decision-making comparing to limit value of signal-interference relation. Thus within each view cycle for each frequency sample the adaptive spatial observation channels are formed, at least by three adjacent spatial channels in horizontal or vertical plane. |
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Invention concerns television systems for underwater inspection. The arm contains underwater research equipment with photographic and video equipment mounted thereon, connected to picture monitor on control panel and supplied with electrically driven lifting gear. The arm is provided with flat arrow-shaped steel wing front-located with three vertical stabilisers serving as construction supporting foot. The wing is cable-towed through lifting gear by water vehicle. Transmitter of surveying echosounder is placed with direction response pattern on the bottom side vertically coaxial with the receiver of satellite grid station. Emitting sector contains control unit, electric motor case with headed screw and two bars fixing provisional weight attached to wing. Two guides between bars are furnished with sealed boxes and underwater lamps provided on both sides. View areas of photographic and video equipment established in sealed boxes are mutually crossed within surveyed surface. The whole view area of photographic and video equipment is overlapped with illumination sectors and two acoustic signal transmitters detecting wing plane position relative to surveyed surface. Real-time control, management and data transfer is performed through multicore cable connecting control unit, picture monitor and operator's stand. |
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Method for determination of sound source bearing The basic wind parameters in the ground surface layer of the atmosphere and the air temperature in this layer are measured, the parameters, standard characteristics of the directivity of the sound detector line groups are computed, the sound detectors are disposed in a definite manner so as to receive the acoustic signals, which then are transformed to electric signals, processed in a special manner, the maximum amplitudes of voltages of these signals at outputs 1 and 2 of the signal processing channels are automatically measured, the difference of the maximum voltage amplitude at output 1 of the signal processing channels and the maximum voltage amplitude at output 2 of the signal processing channels is calculated, the sum of these amplitudes, relation of this difference to their sum are calculated, and the bearing of the sound source is automatically determined. |
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Navigation system, electronic-mechanical chart and autopilot The navigation system uses transmitting radio stations in angles of an equilateral triangle and an electronic-mechanical chart, in which three axles with threaded rods (rotating on these axles) are located under a glass plate with a chart in locations of the radio stations. These rods are coupled in the axis of the location marker on the chart, and two rods are rotated by electric motors from the device for comparison of the differences of the arrival of radio signal pulses from the radio stations and of the difference of propagation of pulses through the rods of acoustic signals. The electronic-mechanical chart is supplemented by an autopilot consisting of a target fix marker with equal-length links with lightly braked ends attached to which are tubes inserted in one another and stretched by springs through which the acoustic signal is propagated in the changed-length line. These tubes are coupled on the location marker on the electronic-mechanical chart, and the device for comparison of the acoustic length of the lightly braked tubes produces a signal for drive of the actuators at a difference of the tube acoustic lengths. |
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The correlation shaper of the directivity characteristic together with the other components of the claimed device made by a definite manner provides in the conditions of occasional input processes the detection and direction finding of several surface and (or) underwater objects being in different points of the space. The result of the claimed invention it's the increase of the device noise immunity solution of the problem of detection of hydroacoustic signals and stabilization of the level of falselarm of the decision. |
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Method for determination of co-ordinates of submerged objects A co-ordinates system with of base length of 2-3 km towed by a ship is produced, each GPS buoy with a built-in hydroacoustic system, composing the base of the co-ordinates system, is linked with the ship with the aid of its cable, which makes it possible, while correcting the cable length to keep the ratio of the lengths of the co-ordinates system in the process of towing, i.e. to keep the deep-sea towered complex in the most favorable zone for high-precision measurements. The buoys can transmit information to the ship with the aid of radio communication or cable. |
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Mode of detection noisy objects in the sea The technical result of the invention is increasing of noise immunity of hydro acoustics system of detection? Realization of prescribed time of accumulation and increasing time of maintenance of acoustics contact with a moving target in the sea. The mode includes the following operations. It is necessary to receive the primary field of noisy radiation of objects with static sheaf of characteristics of direction in the horizontal plane, execute frequency-time processing in each space observation channel, frame, average on time, center and standardize signals to the disturbance, execute observation on the current cycle of survey of received standardized signals and take decision about detection by way of comparison with the threshold value of ratio signal-disturbance. In the process of receiving tracking of energetic parameters of the noisy signal on level, dispersion of the level and selection of local false maximums of noisy signals in the static sheaf of space channels is executed. |
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Mode of detection of noisy objects in the sea The mode includes reception of the primary field of noise radiation in a horizontal plane, at that frequency-time processing of received noisy signals for each spatial channel of observation in the horizontal plane is executed, squared, averaged over the time, centered and normalized towards the interference, accumulation of signals is executed and the decision about detection is taken by way of comparison the reception of the noise with the threshold meaning of the ratio signal-interference. At that the reception of the noise is executed by a static vertical fan simultaneously in several directions of the vertical plane of each spatial channel of observation in the composition of the static fan in the horizontal plane, the reception by each horizon spatial channel by way of choosing the outmost probable angles of reception in the vertical plane for existing hydro acoustic conditions of underwater observation. For these purposes the sea surface is measured, the speed of the signal is measured in the water in dependence of the depth, the level of the noisy signal in the point of reception with given levels of primary field of noise radiation on different distances and horizon according to measured data and known characteristics of the bottom is calculated in each vertical spatial channel deciding the hydro acoustics equitation in passive regime for each object taking into consideration the characteristics of the receiving system, the level of the sea noises are calculated in each vertical spatial channel taking into consideration the characteristics of the receiving system according to measured data and the known characteristics of the bottom, calculated levels of noise in each spatial channel received for given distances to calculated noisy object and horizon are normalized relatively to calculated noise of the sea in vertical spatial channels, the ratio signal-interference is calculated for each distance and horizon of the noisy object in vertical spatial channels, processing of receiving noises with weights, before route accumulation, is executed and summed up with calculated weights. |
Another patent 2531268.