Method for detecting underwater objects and device for realization of said method

IPC classes for russian patent Method for detecting underwater objects and device for realization of said method (RU 2271551):

G01S3/80 - using ultrasonic, sonic, or infrasonic waves

G01S15 - Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems

Another patents in same IPC classes:

Method of classification of noisy objects / 2262121

The method includes reception of the signal of noise radiation of the noisy object by the first receiving antenna and spectral analysis of the received signal of noise radiation of the noisy object, reception of the signal of noise radiation is also performed by the second receiving antenna, separated is the reciprocal spectrum of the signals of noise radiation received by the first and second receiving antennas, measured is the value of the carrier frequency of the autocorrelation function, and the decision on the class of the noisy object is taken at comparison of the measured carrier frequency of the autocorrelation function with threshold frequencies, each being determined as an average frequency of the initial noise radiation band of each standard object of a definite class.

Adaptive seismic correlation object direction finder / 2248015

Direction finder can be used for taking azimuth relatively guarded objects at guarded areas, calculating number of objects in group target and classifying found objects. Direction finder has two seismic receivers, two processing channels with delay lines and correlators, maximal signal selector, correlator, testing module, commutator and calculator. To realize the direction finding function the method of passive diversity detection and ranging is used. The main information criterion for finding direction to object has to be the function of mutual signals correlation in two signal processing channels. Value of azimuth is judged from value of signal delay. Change in value of signal delay is equivalent to controlling directional diagram of seismic active aerial which allows classifying detected objects separately. Test influence is used for adaptation of speed of propagation of seismic wave which changes under influence of meteorological conditions. Current value of speed of propagation of seismic wave is judged from time of delay of test influence signal coming to second seismic receiver. Tuning of lines of delay is conducted correspondingly to those changes.

Method for controlling behavior of sea mammals during fishing / 2271022

Method includes masking low frequency hydro-acoustic signals of fishing ship selecting device, at least one false supporting buoy with or without catching implement is mounted, which emits high frequency hydro-acoustic signals, connected to mark or marking buoy, which emit light signals, decrease noticeability of fishing ship for sea mammals of working fishing implements, decrease noticeability of fishing ship for sea mammals during picking up working catching implements due to decreasing broadband hydrodynamic signals of steering device of fishing ship and decrease of broadband hydrodynamic signals of driving shaft of fishing ship, light signals of fishing ship are disabled, broadband hydro-acoustic signals of picked up fishing implement are masked by emitting broadband hydro-acoustic signals by hydro-acoustic transformer, hydro-acoustic signals of ultrasound frequencies spectrum are emitted by several hydro-acoustic transformers.

Method for determining cable-laying route and depth for underwater cable / 2271021

In accordance to method for determining cable-laying route and depth for an underwater cable, low-frequency electromagnetic signal is transmitted along the cable, by means of watercraft positioned on the surface of body of water receipt antenna adjusted to same frequency is moved above underwater cable close to bottom of water body, signal received by receipt antenna is transmitted to processing block mounted on aforementioned watercraft and on basis of distribution of levels of electromagnetic field above underwater cable, route and laying depth of underwater cable in bottom of water body are determined, while close to bottom above the cable a system is positioned consisting of receiving all-directional antennas, receipt antennas are distributed over space in accordance to certain plan, so that their mutual position relatively to each other does not change during movement, transformer is connected to system of antennas, which is connected to each one of receiving antennas and through control cable is connected processing block on watercraft, in transformer signals are received from each one of receipt antennas, their parameters are optimized and serially transmitted along control cable to processing block, in which electromagnetic field levels are memorized, received by each receiving antenna of system, echo-sounding device is mounted on watercraft which is utilized to determine position of receiving antennas relatively to bottom of water body, in accordance to data about position of each receiving antenna of system and levels of electromagnetic signals received by aforementioned antennas distribution of electromagnetic field levels in space above underwater cable is determined, which is utilized to determine laying route by position of maximal values of levels and laying depth of underwater cable in water body bottom by comparing maximal values to support value.

Method for researching environment / 2269141

Method is based on emission of probing signal, receipt and processing of reflected signal, on measuring of signal level, determining on basis of signal level, and also length of its delay of presence and position of object or presence of unevenness in environment, while, presetting thickness of researched layer and distance to it, layer-wise probing of environment is realized by emitting probing signal of limited length and performing processing of received reflected signal in time range, displacement of which relatively to starting moment of emission of probing signal and length are determined in accordance to equations: τ≈D/(c/2); T_r≈Δ₁/(c/2)+T_p, where τ - displacement of aforementioned temporary interval; D - distance to researched layer; c - speed of expansion of probing signal; T_r - length of aforementioned temporary interval; Δ₁ - thickness of researched layer; T_p - length of probing signal.

Method for finding object avoiding detection / 2262719

Method includes, at the moment of beginning of sweep, observers, evenly positioned along edge of search district at distance R₀ from its center, moving from periphery to center of search zone along spiral, determined in such a way, so that angle between observers movement vector and direction to zone center was value μ_i, determined from mathematical formula

Method and device for calibration of hydroacoustic measurement equipment when estimating fish stock / 2260817

Method and device can be used at research and development and fishery ships for estimation of fish stock. Reflective characteristics of fish are measured by means of hydro-acoustic measurement equipment. Sizes, spatial position and number of fish are determined independently from video signals of stereo television equipment while simultaneous hydro-acoustic sound recording and video review of parts of water medium is performed from one single point. Video images of fish and fish schools are selected and stored which video images correspond to moments of reflection of maximal echo-signals when signals cross fish or fish schools. Stored sequences of maximal echo-signals are corrected while taking results of processing of selected video images into account. Selected sequences of video images of maximal video signals from fish and fish schools are selected separately and stored. Device for realization of the method has hydro-acoustic and video sections, acoustic and video data registration, processing and store unit, selective sampling and storage of maximal echo-signals units and video image intermediate store unit.

Method for automatic following of maneuvering target in mode of active location of hydroacoustic or radiolocation complex / 2260197

Method is based on emission of proving signals, receipt of echo-signals by receiving main of active location mode, detecting in each i-numbered observation cycle of single marks of maneuvering target, receiving appropriate values of coordinates - distance and signal, building strobes of following and selecting of marks, caught in following strobes, smoothing coordinates of selected marks with consideration of data, received within limits of sliding temporary windows, and determining extrapolated coordinates of maneuvering target for next observation cycle, on each i-numbered observation cycle during following of maneuvering target value of Doppler displacement of frequency of echo-signal is measured, which is used to determine value of radial component of speed of maneuvering target, receipt main of passive location mode is used to receive signal of own emission of maneuvering target, receipt main which are used to determine angular speed of maneuvering target, while smoothing of coordinates of maneuvering target is performed in polar coordinates independently with consideration of radial component of speed of maneuvering target and angular speed of maneuvering target, within limits of sliding time i windows from given number N of observation cycles, including i-numbered cycle and N-1 cycles before it.

Acoustic direction pointer (variants) / 2260194

Device has power source, receiving device, device for forming probing pulses, device for control and synchronization, indicator and antenna, and also has receipt converters commutator and indicator element commutator, antenna has emitter of acoustic pulses and three receipt converters, indicator has three columns of vertically positioned indication elements.

Method for determination of true speed of ship at calibration of logs in hydroacoustic traverse trial line / 2259572

The method includes radiation and reception in equal intervals of time of acoustic signals and measurement of the time of propagation of signals from the ship to each of the hydroacoustic bottom transponder-beacons, additionally measured is the propagation velocity on standard horizons from the water surface from the bottom, measured is the depth of submersion of the ship transceiving antenna, the depth of installation of the bottom transponder beacons, determined is the distance in the horizontal plane from the ship transceiving antenna to each bottom transponder beacon (d₁,d₂), and the longitudinal, traverse and complete true speeds of the ship are calculated.

Method for hydroacoustic detection of swimmers and biological sea beings and their extrusion from water intake structure / 2256196

Proposed method designed for protecting water intake structures of nuclear power stations against intrusion of wreckers and for use in fish industry to protect water intake structures against biological sea beings includes formation and amplification of high-frequency pumping waves at frequencies ω₁ and ω₂, pumping signals at frequencies ω₃ and ω₄, high-frequency waves at frequencyω₅, and their radiation onto metal shielding screen of water intake structure, generation of low-frequency wave of differential frequency Ω = ω₁ - ω₂, generation of high-frequency waves of combination frequencies ω₃ ± Ω' and ω₃ ± Ω", ω₄ ± Ω' and ω₄ ± Ω", separation of low-frequency signals at frequencies Ω' and Ω" by detection method, spectral analysis of high-frequency signals, and their comparison with reference signals, whereupon decision is taken on detection of sea being, classification, and determination of heading, speed, and spatial coordinates of sea being, on continuous attack of metal shielding screen of water intake structure where biological sea beings occur with high-frequency waves at frequency ω₁ for hydroacoustic cleaning of water intake structure.

Method for hydroacoustic detection of swimmers and biological sea beings and their extrusion from water intake structure / 2256196

Transducer of velocity projections with respect to vehicle / 2246738

According to the first version, the device comprises four single-beam Doppler velocity pickups, two circuits for adding frequencies, three AND circuits, and control unit. According to the second version, the device has four single-beam Doppler velocity pickups, two circuits for adding frequencies, two circuits for subtracting frequencies, six AND circuits, and two control units. According to the third version, the device comprises four single-beam Doppler velocity pickups, two circuits for adding frequencies, four circuits for subtracting frequencies, nine AND circuits, and three control units.

Method for high-directivity radiation and reception of broadband hydroacoustic signals / 2247409

Proposed method that can be used for marine geological and geophysical investigations, search for sunk objects, and the like, and also in fish industry for searching and evaluating fish reserves includes generation of high-frequency pumping signals at frequencies ω₁ and ω₂, their amplification, and radiation into water medium, generation of differential-frequency wave Ω = ω₁ - ω₂ in water medium for locating investigated object, and reception of reflected differential-frequency wave Ω'; high-frequency pumping signals ω₁ and ω₂ are close to resonant frequency of air bubbles ω₀ in water surface layer and are close to investigated object frequencies; in addition high-frequency pumping signal is generated at frequency ω₃ close to second harmonic of air bubble resonant frequency ω₀, amplified, and radiated into water medium; high-frequency signals are also received and amplified at combined frequencies ω₃ ± Ω', then they are demodulated and filtered off to produce broadband signal of resonant frequency Ω' reflected from investigated objects.

Method for high-directivity radiation and reception of broadband hydroacoustic signals / 2247409

Method of plotting sea bottom navigation chart / 2248007

Proposed method includes running around preset area and radiation of acoustic pulse signal towards sea bottom for each point of navigation chart, forming directional pattern of receiving antenna, reception and conversion of acoustic pulse signals reflected from interface into electrical signals which are amplified and separation of the envelope of these signals; the envelope of electric pulse signals from output of receiving channel is transmitted to analog-to-digital converter which takes accesses of the envelope at digitization frequency equal to double bandwidth of receiving channel from moment of radiation of acoustic pulse signal to moment equal to time required for its passage through preset depth and vice versa; accesses taken in this interval are divided into maximum magnitude of access in this interval; magnitudes are placed according to geographic coordinated and are stored in digital form as digital navigation chart of sea bottom.

Method for controlling sea mammal behavior in fishing / 2248008

Method involves building and emitting information and energy sonar signals for controlling sea mammal behavior (including sea mammals having no natural predators) when catching fish in great volume of aquatic medium. The control actions are done in effective and short-term manner in frequency bandwidth restricted with frequency bandwidth being maximum sensitivity to fishes selected as fishing object. The information signals are built in unit for producing information signals in the channel for producing and emitting information signals being like sonar signals emitted by selected fishing equipment, fishing-boat body, systems and mechanisms when moving to fishing area or setting fishing gears. At the same time, several autonomous marine systems are installed and set in operation far from fishing area in water column at different horizons by switching on electric current. Light emission signals are sent at the same time according to program executed by the unit for producing and amplifying information signals. The sonar signals and light signals have an effect upon sea mammals and modify their behavior characteristics.

Method for determination of distance in hydroacoustic network / 2248586

The method consists in preliminary assignment and storage of each i-th of N parties (P) in the form of the respective signal of acoustic velocity c_i in the aqueous medium, preliminary assignment and storage at the central station and at each of N(P) party in the form of the respective signals of fixed time interval T_c.s, transmission by each i-th P in the direction of the central station of the respective i-th acoustic signal-interrogation after reception by this i-th P of the respective i-th acoustic signal-resolution from the central station, reception at the central station of the mentioned i-th acoustic signal-interrogation, transmission from the centralization in the direction of the i-th P of the respective i-th acoustic signal-reply on expiration of T_c.s. counted-off from the moment of detection at the central station of the mentioned i-th acoustic signal-interrogation, reception by the i-th P of the i-th acoustic signal-reply, measurement at the i-th P of time interval Δτ_i from the moment of transmission by the given i-th P of the respective i-th acoustic signal-interrogation to the moment of detection by this i-th P of the respective i-th acoustic signal-reply, and determination of distance D_pi from the i-th P to the central station according to rule: D_pi=c_i·(Δτ_i-T_c.s.)/2.

Method and device for measuring radio location reflectivity and doppler shift by means of radar / 2249230

Invention can be used in meteorological radars, 360 degree survey radiolocation stations as well as for remote sounding and sonar systems. During process of measuring of characteristics by radar of sonar the pulses are transmitted and signal is received between transmission of pulses, which signal depends on transmitted pulses and on distribution of characteristics of target at different ranges. Transmitted pulses form cyclically repeated code or continuously changing sequence of pulses. Distribution of characteristics is determined by means of representing the pulses in form of set of linear equations where variables have to be values of characteristics measured at required distances. The set of equations should be subsequently solved. As a result the conflict between measurement of power and Doppler shift is eliminated.

Method of finding poaching fishing tools placed on ground or inside bottom layer of deposits / 2249233

Vessel being involved in finding poaching fishing tool tows underwater apparatus by means of cable-rope. There is satellite navigation system on the vessel which allows high-precision determining coordinates of vessel. There is also computer on the vessel providing control for operation of all sections disposed on vessel and in towed underwater apparatus. Computer finally solves the problems of efficient finding, detecting, identifying and determining of space coordinates of poaching fishing tools located on ground or bottom deposit layer. Sea biological objects generate wide-band signals which objects sit in traps connected to each other by halyard.

Method of detecting signals / 2249833

Method allows detecting sonar signals inside real channel of propagation when distortion of signal is taken into account which distortions appear at reflection and dissipation of waves at boundaries of channel as well as phenomena of signal total internal reflection. Method of detection of bandwidth signals consists of operations of mutual-correlation comparison of accepted realization with copy of irradiated signal and making decision on detection. Accepted realization of mutual-correlated signal is compared with Gilbert-image of copy of irradiated signal; results of mutual-correlation comparison of accepted realization with reference and Gilbert-image of reference of irradiated signal are squared and summed. Calculated value is compared with threshold one.

FIELD: hydro-acoustics, possible use in hydro-locating technologies for detecting underwater objects like submarines and small objects like mines and underwater swimmers.

SUBSTANCE: method includes determining, in the moment of temporary position of expanding spatial angles wave front, tracking belonging to acoustic beam (bearings) for each reflective element, positioned in wave packet of reflected signal (in space between frontal and back fronts of signal pulse, and limited body angle of direction characteristic of receiving antenna. Spatial receipt on basis of spatial-phase and spatial-correlative processing of reflected signal provides for detecting difference between spatial positions of reflecting objects within received signal wave front, which provides more information for object detection and, due to that, principally distinguishes the method from commonplace amplitude-temporal signals processing technology.

EFFECT: limited reverberation effect due to organization of spatial processing of signal.

2 cl, 6 dwg

The invention relates to the field of hydro-acoustics and can be used in sonar devices detect underwater objects (submarines, small objects: min, underwater swimmers), intended for use in areas with high levels of reverberation interference caused by shallow, complex topography, rough water surface.

For the assessment of novelty and technical level of the claimed technical solution consider a number known to the applicant of technical means for a similar purpose, which is characterized by a set similar to the claimed invention of the signs.

A known method for detection and location of underwater targets for protected marine areas, the essence of which is that by using the focused laser beam in place of the proposed location of the target in the protected marine areas initiate shock sound wave or a series of sound shock waves. Reflected from underwater targets sound waves together with initiated sound waves are taken sonar receiver with the beam directivity. Processing the received signals allows the detection and tracking of underwater targets. To ensure the secrecy of the detection system, which is achievable technical is the result of Kim, the amplitude of the sequence of sound pulses set at or below sea level of noise or interference marine waters, see RF patent №2176401.

There is a method of detecting underwater objects on the Maritime boundary in the shallow sea, which emit directed into the upper half-space acoustic impulses from a number of points with known coordinates, located at the bottom of the on-line abroad, take reflected from objects the echoes in these same points, and the position of the object is judged by the coordinates of the receiver detecting the signal, emit pulses in neighboring points at different frequencies and at all points at the same time, take each point echoes the natural frequencies and at least two other frequencies from the next in line emitters on each side, the distance between adjacent points of reception-radiation is chosen equal to twice the water depth along the line of the boundary, the time of arrival of the echo signals limit the time of arrival of reflected from the surface of the sea of pulses on each taken at a given point frequency, and location of the detected object specify the coordinates of the emitters operating at a frequency of the received echoes. Monitor the level of direct acoustic pulses received from the neighboring emitter, and changing this level is judged on the appearance of the object near the bottom. Technical the definition of the result is to ensure reliability and continuity of control, the exception is in areas of poor reception, see RF patent №2161319.

There is a method of detecting underwater objects, based on the radiation control area set the tone-modulated signals, carrier and modulation frequencies are selected in accordance with a proposed size of objects, their position relative to the surface of a pond and speed. Signal refiltration in accordance with the measured, detects each channel and the weakening of the respective component is judged on the presence, size and motion parameters of the objects. Device for the detection of underwater objects contains an emitter, a power amplifier, oscillator, modulator, block of the set of carrier frequencies, the unit of the set of modulation frequencies, a receiving antenna, amplifier, multi-frequency filter, Neskuchniy detector, indicator, see RF patent №2008692.

There is a method of intrusion detection underwater object in the monitored region in-situ reservoir, consisting in successive irradiation using sonar emitter various zones controlled water areas and reception of the acoustic signal, prothymocytes with underwater object hydroacoustic receiver, with subsequent determination of the location, course and speed of a moving object from the parameters the frames of the received signal, see U.S. patent N4319349.

There is a method of intrusion detection underwater object to controlled waters in-situ reservoir, the essence of which is that using sonar reflectors placed in an elliptical surface, define a controlled area in-situ reservoir. The foci of the elliptical surface have a sonar emitter and receiver. The emitter is carried out in a circular hydroacoustic antenna, and a receiver connected to the circular indicator review - with uniform directional characteristic. Consistently on different areas of the emitter sends pulses of acoustic energy, which for the same period of time reach the receiver, reflected from the sonar reflectors. The indicator of the circular review formed the series of pulses. With the invasion of the underwater object in the monitored zone, one of the pulses on the display circular view disappears, which indicates the presence of target. Sequential processing of the output signals allows to determine the course and speed of target movement. The technical result is to increase the ratio of signal to noise and secrecy of the ongoing search and target tracking, see RF patent №2150123.

The main technical problem of all known hydroacoustic way the detection of underwater objects is to limit the impact of reverberation noise, i.e. increased robustness of detection.

There are various ways to limit the impact (reduce) the reverberation interference with the task of object detection. Mostly they are connected with the power characteristics of the reception of reflected signals (see, for example, J. Urik fundamentals of hydro-acoustics, L, Shipbuilding, 1978, s-259). When this limit reverberation interference provided by the reduction of the wave packet echo (spatial volume of simultaneous reception of reflected signals), which is achieved by increasing the spatial resolution in range (along the path of signal propagation) by reducing the duration of the emitted signal and the edge signal by narrowing (reduction in solid angle) directivity (CI) is the radiating and receiving antenna.

In some cases these methods has exhausted its possibilities. Further reduction of the duration of the signal and narrowing the directivity characteristics of the radiating and receiving antennas reduces not only the number of interfering reflectors, while participating in the formation of the reflected signal, but also reduces the reflective surface of the object, simultaneously participating in the reflection, i.e. to reduce the amplitude of the reflected from the object signal, which is unacceptable from the point of view of providing the appreciation is of immunity of the reception. There is therefore need for new ways to limit the impact of reverberation, which can increase the spatial resolution in the reception within the minimum spatial volume of the wave packet echo.

From the task pane, hydro-acoustics related to the study and display of spatial patterns detected objects (for example, when mapping the seabed) is known technical solutions that ensure the separation of sources of reflection, lying in the vertical longitudinal (axial) section directivity receiving antenna. In particular, information about the spatial position of the reflectors relative to the axis XH within the wave packet of the reflected signal allows to obtain the principle of interferometry acoustic beam. The implementation of this principle implies the reception of the echo signal into two identical HN receiving antennas are separated by vertical phase centers in the plane perpendicular to the direction of reception.

Use of the method of interferometry in foreign side-scan sonars (see, for example, Review: the Development of sonar systems measure the depth on the basis of side-scan sonars, Shipbuilding abroad, No. 1, 1987, p.76-80) allowed to move from the multibeam reception narrow diagrams (vertical fan) to one of the wide beam with obvious advantages in detail elements of the bottom topography. In these Pinger spatial position of the reflecting object is logged distance and angle (vertical bearing), determined by the phase difference of the reflected signal received at two spaced antennas. In sonar Atlas GFBS30 ( Bathymetrical Fan Beam Sonar Atlas GFBS30 Technical Proposal, Krupp Atlas Electronic, 1987, IX) the principle of interferometry is implemented in 90-degree HN by creating a pre-calculated 64 increments of time delay within the duration of the pulse is taken at two spaced antennas, which is similar to 64 beam echo sounder.

Provided technical solutions for direction finding in one (vertical) plane, aimed at revealing the structure of the reflective surfaces, in particular surfaces of the bottom, can be used to improve resolution in space (azimuth and elevation) within a solid angle HN receiving antenna by two-plane direction finding reflectors, both located in the plane of the front of the received signal.

Closest to the proposed invention, the physical essence of the method is implemented in sonar firm Ferranti (UK) (Jane's Defence Weekly, 1987, 7, 18/IV, No. 15, 743; The Daily Telegraph, 1987, 24/VIII, No. 41 082,8.) (Shipbuilding abroad, No. 12, 1987, s) and based on the radiation in the water space of the pulse is snogo signal (s), receiving echo signals on two separate hydroacoustic antenna, carrying out the review space in horizontal and vertical planes defining high-resolution bearing (azimuth)and tilt angle (elevation angle) and the distance to the target. The detection is performed according to the coordinates of the reflecting object with predefined values.

The disadvantage of this method is the lack of effective action to limit the impact of reverberation.

The basis of the claimed invention based on a solution to the problem of increasing the noise immunity of the detection of underwater objects by limiting the impact of reverberation interference by division of marks from interfering reflector in the plane of the front of the received signal in accordance with their spatial position relative to the axis of directivity of the receiving antenna.

The essence of the object of the present invention, the method is expressed in the following essential features sufficient to achieve the above provided by the invention a technical result.

The way to detect underwater objects, according to which scuba controlled space is irradiated with acoustic signal, receive reflected from the object signals on separate receiving the hydroacoustic antenna, conducting survey of controlled underwater space in horizontal and vertical planes, characterized by the fact that determine at each moment of time during the cycle, the radiation-receiving angles of arrival of the reflected signals in the horizontal and vertical planes by determining the phase difference between pairs of signals received by the respective pairs of receiving antennas spaced in horizontal and vertical planes of the phase centers in the plane of the front of the reflected signal, determine for each moment of reception of the current histogram density distribution of angles of arrival of the signal in both planes, by determining the residence time of the observed angle of reception in each interval of angles in sectors of the characteristics of directional receiving antennas for the duration of the emitted signal, determine the maxima of the density histograms of these distributions, which by multiplication determine the current implementations of the values of the maxima of the two-dimensional density distribution of angles of arrival of the reflected signals in the plane of the front of the received signal, and in these implementations, averaged over several cycles of the radiation-receiving, guide the implementation of the current detection thresholds, and in excess of the maximum of the histogram of the density distribution of the angle of arrival of the received signal is hell threshold judge about the discovery of the underwater object.

In the proposed method, the limitation of exposure of the reverb is achieved through the organization of spatial signal processing.

The physical essence of the method consists in determining at the time of the interim provisions of the propagating wave front of spatial viewing angles of the acoustic beam (bearings) on each reflective element located in the wave packet of the reflected signal (in the space between the front and rear edges of the pulse signal), and the limited solid angle of directivity of the receiving antenna.

From devices that implement the hydro-acoustic methods of detection of underwater objects, known pievescola coherent sonar system, which is designed to detect underwater objects and classify them in real-time and consists of low-frequency broadband radiating system is not in piezoceramic transducers and receiving system, executed on a piezoceramic transducers. When the radiation of the acoustic field perform amplitude-phase distribution in wide frequency band on a pre-prepared law modulation of the emitted sweep, then the equations for the radiation of the acoustic field are simultaneously supporting equations in software-algo is the rhythm of the process of reception and processing of acoustic signals, see RF patent №2204150.

Closest to the proposed device is a physical entity is hydroacoustic equipment used in the sonar firm Ferranti (UK) (Jane's Defence Weekly, 1987, 7, 18/IV, No. 15, 743; The Daily Telegraph, 1987, 24/VIII, No. 41, 082,8) (Shipbuilding abroad, No. 12, 1987, s).

The essence of the object of the invention is a device designed for the implementation of the method described above, is expressed in the following essential features sufficient to achieve the above provided by the invention, the technical result.

A device for implementing the above method of detection of underwater objects, including hydroacoustic equipment, characterized by the fact that the latter is in the form of a sonar receiving-emitting system installed on the platform in the sea, including directional transmitting antenna and at least three identical and coaxial directional receiving antennas spaced apart in the plane of the front of the emitted signal in the vertical and horizontal phase centers, electrically connected with external amplifiers radiated and received signals, also mounted on the platform and connected to the main communication cable remote control installed on the shore, and containing a power supply external amplifiers, blocks of phase d is Taktarov, managing and registering the electronic computer that includes the block of digital information processing and control unit, and the outputs of the receiving amplifiers through the trunk communication cable is connected to the inputs of the phase detectors of horizontal and vertical direction finding, the outputs of which are connected to the input of the block of digital information processing in computers, one output of which is connected to the tool for the visualization of the results of information processing, and the other output from the control unit electronic computers connected to the input of the power amplifier of the radiated signals.

The invention is illustrated by drawings, where figure 1 shows the principle of determining positions where A₁, A₂And₃- reception of the acoustic antenna phase center which is spaced a distance d in the horizontal and vertical planes, figure 2 is a typical view of the spatial position of the marks (in-plane angular coordinates)corresponding to different angular position of the reflector relative to the axis of the chart in figure 3 - waveform of the received signals across a distance sensing, corresponding to different detection methods, figa shows the dependence of the signal amplitude in the case of amplitude-time processing (when the m on one of the three antennas), and figb shows the same waveform signal corresponding to the value of the maximum of the histogram of the angles of arrival of the echoes in the solution of the reception characteristics, figure 4 presents a General view of the transceiver of the device that implements the claimed methods detect underwater objects, figure 5 - General view of the remote control, 6 is a block diagram of the device (power supply conventionally not shown).

Device for the detection of underwater objects consists of pievescola sonar system 1, fixed by means of the housing 2 on the platform 3, installed in the water. The antenna system includes one transmitting directional antenna 4 and three directional receiving antennas 5, 6, 7. The layout of the antennas is made so that the axis of the directivity characteristics of all of the antennas are parallel, and the receiving antenna is installed so that it can be a spatial reception of the two groups of antennas spaced phase centers in the plane perpendicular to the axis of the directivity characteristics. A pair of receiving antennas 6 and 7 forms a receiving group exploded phase centers in the horizontal plane, and a pair of antennas 5 and 7 in the vertical, the total antenna groups is the antenna 7. Separation of the phase centers in both groups equally 4λthat at the operating signal frequency of 50 kHz is 12 see the same rusmarket aperture antennas, ensuring the width of the directivity at the level of 0.7 from the axial maximum of 15° in both planes.

Inside the housing 2 is placed external amplifier comprising: an amplifier radiated signals 8 and amplifiers of received signals 9, 10 and 11. The amplifiers 8, 9, 10 and 11 are electrically connected trunk cable 12 remote control 13, placed on the shore. The control unit 13 consists of a housing 14 within which is placed a power supply external amplifiers 15, the blocks of the phase detectors 16 and 17 defining the phase angles of the delays of arrival of the signals from the receiving antennas 5 and 6 relative to the signals received by the reference antenna 7, the phase detector implemented by the hardware, providing the measurement error of the phase angle at the level of the model phasemeter ˜δϕ=10° (Webistrano, radio system, Meters, Radio and Communication, 1985 s), which in terms of the magnitude of the spatial angle with the device in the sector directivity 15° is 0.05 degrees.

On the housing 14 of the remote control 13 posted by managing and recording electronic computer (PC) 19, which includes a digital processing unit information 18 and the control unit 22, a monitor 21 and a keyboard 20. The control unit 22 is connected to the output unit of the digital information processing 18 and provides upravleniemoeda signals, when the output control unit 22 is connected to the input of the external amplifier radiated signals 8.

The digital processing unit information 18 associated with the outputs of the phase detectors 16, 17 and performs computing functions for receiving and processing information received from the outputs of the phase detectors 16 and 17, the block of digital information processing 18 provides data visualization processing on the monitor screen 21 that is installed together with the keyboard 20, and output a visual graphical and numerical information on the machine-readable medium 23.

The device communicates with the personal computer 19 via a hardware interface standard - input Ethernet 10/100 Base-TX network card, which are part of the device (not shown). Communication device with the PC made by any known method.

Recording and computing device functions to receive and process information is implemented in the system PC using daemon that runs from the keyboard 20, the digital processing unit information 18 for a given program is the construction of the current density histograms of the distribution of angles of arrival of the reflected signals on the horizontal and vertical channels are calculated maxima of the two-dimensional density distribution of angles of arrival for each point in time of reception of the reflected signal is, obtained temporary implementation of the maxima for each period of radiation for a given number of periods of the radiation are averaged and stored as a threshold with which compares the calculated values of the maxima of the two-dimensional density distribution of the reflected signals for each time of reception, by comparing the results judged about the discovery of the underwater object.

The method is implemented as follows.

The reflected signal at the frequency ω_oflows through the acoustic beam angles (bearings) α and β (1) to the axes of the directional characteristics of the receiving antennas in the horizontal and in the vertical plane. Receiving echo signals from each direction of space is made on a group of three identical and coaxial directional antennas, which are formed two pairs (A₁And₂and A₁And₃) receiving antennas exploded phase centers in the horizontal and vertical planes. When one of the antennas (A₁) is common to both groups.

The study of the probing signal is a separate radiating antenna. It is also possible radiation signal by using one of the three receiving antennas. Emitting signals are pulses with high resolution: simple (with tone shading) pulse signal duration t_about, or complex wideband signals with the same effective duration of t_eff=t_aboutobtained by coherent processing (compression) of a received signal. The duration of the signal should be as minimal as possible, but not less than the time length of the detected object t_about≥2L/C, where L is the length of the object, C is the speed of sound in water. For detection of large object-type submarine (L=75-150 m) signal duration should be about 100-200 MS, and for the detection of small objects of type underwater swimmer t_about≈1-2 MS.

The fill rate of the signal must be in the range of 2-3 kHz for detection of large objects and 200-300 kHz detection of small objects. When the radiation of complex signals in the frequency band filling should be Δf=1/t_o.

Information about the value of the horizontal and vertical direction toward the reflectors in the wave packet is determined by the phase shifts between signals taken at spaced antennas is proportional to the signal delay time in antenna A₂relative to A₁and the signal in the antenna And₃relative to A₁.

The complex amplitude of the reflected signals from the object located in the wave package adopted spaced antennas can be represented in the form

p> where U(t) is the unit impulse function, equal to unity at t+t₃+t_o≥t≥t+t₃and zero at other t;

And the amplitude of the received reflected signals (given the conditions of reception, when the corners α and β not large, the amplitude of the signals of all antennas can be considered approximately the same);

t₃the time delay of the reflected signal (t₃=2 r/s), defined by the distance r to the object;

ω_othe average fill rate signal;

F_α=ω_aboutτ'_αand f_β=ω_oτ'_β- appropriate phase shifts (phase angles of arrival) of the received signals between pairs of neighboring antennas;

τ'_αand τ'_βthe time delay of the received signals between pairs of neighboring antennas.

The values of the angles of arrival of the reflected from the object signal in the plane of its phase front can be determined from the phase difference of signals received by adjacent pairs of antennas, using the following formula:

This method, based on spatial-phase processing of the reflected signals, is the technical essence of the first independent object of the claimed invention.

As follows from formulas (2), the values of the angles of arrival of signals from the object can also be determined is whether time delays of the signals, adopted spaced antennas. For this you can use the two-plane functions vzaimosohranenii these signals.

Two-plane functions vzaimosohranenii signals from respective pairs of antennas taking into account expression (1) can be represented as follows:

whenandother t₃;

whenand other t₃; (3)

The maximum values of these functions are achieved in time

t=t₃=t_about+τ_αand t=t₃=t_about+τ_β.

Phase angles (f_α=ωτ_αand f_β=ωτ_βin exhibitors correlation functions can be determined by taking the relations of the imaginary and real parts of the expressions (3), i.e. in the form:

where Im and Re - designation of the imaginary and real parts of the complex function.

Given the smallness of the angles α and β (removal of the object from the antenna at a distance of r≫ (d) expressions for determining the direction to the reflecting object can be obtained in the following form:

Thus, in the plane orthogonal CCW is dint, coinciding with the position of the wave front of the signal at the time of reception t₃=τ_α+t_aboutand t₃=τ_β+t_aboutfunction vzaimosohranenii the reflected signal received at spaced antennas have a maximum that is proportional to its energy, and the location of a reflecting object in the plane of the viewing angles α and β also determined by the group of coordinates: α, β and r (t₃)7

Summarizing the above expressions for multiple sources of reflection within ray tube directivity of the antenna, the reverberation signal can be represented as:

where i is the number of elementary reflector (i=1,2,...N);

N is the number of elementary reflectors in the wave (pulse) package echo;

- reflectivity elementary reflector with angular coordinate α and β with respect to an axis of directivity.

In the proposal of mutual independence of the elementary reflectors, which is characteristic of a mathematical model of reverberation, cross-members function vzaimosohranenii pairs of signals (6) vanish, and the function of vzaimosohranenii signals on pairs of receiving antennas in the vertical and in the horizontal planes are of the following type.

Where- spatial function vzaimosohranenii signal from elementary scatterer.

Each lens corresponds to an angular vector with its angular parameters α_iand β_idefined similarly to expression (5).

In the parameter area, delay τ_αand τ_βcorresponding to the reception signal, grouped region scatterer parameters_iand. Output signal corresponding to this area will be in the form:

where M is the number of elementary reflectors, processed with angles of arrival

The first term in the right part of expression (8) represents the function vzaimosohranenii signal from the object observed on the background reverberation scatterers.

Characteristic appearance of the spatial position of the marks (in-plane angular coordinates)corresponding to different angular position of the reflector relative to the axis of the chart shown in figure 2. In square box indicator of the angular positions of the marks displayed signal information corresponding to the area of the wave front within the cross-section diagrams of the antenna, udalen the mu from the receiving antenna at a distance r. Horizontal field indicator deferred corners αand vertical angles β. The middle of the field (α=β=0) corresponds to the axial direction of the characteristics of the receiving antennas. As can be seen in the upper part of the plane wave front focus group marks caused by signals reflected from the water surface and at the bottom from bottom reflectors. Mark from the reflective object in the water column on the axis of directivity of the antenna is located in the centre of the square.

Both methods spatial admission on the basis of spatial phase and spatial-correlation processing of the reflected signals allow to distinguish the spatial location of reflecting objects in the plane of the wave front of the received signal that gives more information for object detection and fundamentally distinguishes this method from the traditional amplitude-time signal processing. In this case, when receiving one (out of three) of the antenna and the amplitude-time signal processing, at the time of reception t=t₃there would have been a total amplitude of the signals from all reflectors within the wave packet of the reflected signal.

View information about underwater reflector in the plane of the front of the reflected signal that is used to separate the receive spatial what about the distributed reflectors, radically changing the conditions of the detection object. If amplitude-time processing of the detection target signal is made on the background of the total signal from all interfering reflectors, when the correlation detection signal/interference is characterized by the amplitude of the most "strong" interference reflector.

To formalize the process of discovery in the plane of the viewing angles (α, β) builds a two-dimensional histogram W^α,β(t₃)characterizing the density (time) direction to the reflecting objects, measured at the time of observation t₃averaged over the duration of the pulse t_aboutand falling into the cell α_ithat β_j.

To build the histogram value sector of observation angles α and β is selected from the two conditions. The first condition gives the minimum limit. The minimum value of the sector is determined by the width (typically at the level of 0.7 of the maximum directivity of the receiving antenna in both planes, which depends on the size of the antenna:

where λ is the wavelength of the acoustic signal, and D is the linear dimension of the antenna.

To reduce reverberates exchange width characteristics of the antenna at the operating frequency should be as small as possible. At the same time practicesalways restrictions on the physical size of the antennas, due to technical and economic requirements, and usually D≈(3-5)λ. For D=3λ width characteristics of the receiving antennas (2α_0.7(2β_0,7) is about 15 degrees.

The second condition gives an upper limit. The maximum value of the sector is determined by the value, which can be obtained unambiguous (within one complete cycle of measurements of phase angle equal to 2 CT) values processed corners α and β.

Given that the sector intake should not exceed sector unambiguous direction finding, from the equality of the expressions (9) and (10) should be required to select the magnitude of the separation of the phase centers of the receiving antennas:

When constructing a two-dimensional histogram plane angles reception α and βi.e. selected above sector ±α_max=±α_0.7and ±β_max=±β₀,₇divided by n_αand n_βcells, the width of which is determined by the measurement errors of the angles of arrival of the signal

where δ'_αand δ_β- error of measurement of the angles of arrival of the signal phase by the method of direction finding.

The magnitude of the error (δ'_αand δ_βdepend explode receiving antennas (Vbbackup Radio system, M, Radio and Communications. 1985 s) and are determined by the formula

Taking into consideration the requirements for the maximum diversity receiving antennas (11) and taking into account expressions (9) and (13), the number of cells to build a histogram of the angles of the signals must be 50×50.

For each time t₃cycle emission-reception separately constructed histograms of the angles of arrival (bearing) and in elevation, selects a maximum value

The resulting implementation of W_max(t₃) are stored and averaged over several cycles and is used to generate the current detection threshold W_p(t)=<W_max(t₃)>. The number of cycles of averaging, depending on the period of agitation of the water surface can vary from 10-12 up to 80-100.

When the characteristic of the receiving antenna of a reflecting object in excess of the maximum of the histogram above the threshold W_max(t₃)>W_p(t) the decision about his discovery.

The effect of the method was verified experimentally in situ to detect underwater swimmers disturbances in complex conditions of the waters caused by shallow waters with depths from 2 to 7 m, excitement with a wave height of 0.5 m, and the complex reliefs and structure of the seabed.

In the water radiates simple Tonalin the e signals with a frequency of 50 kHz with a duration of 1 MS. Echoes from the water were taken at the same three receiving antennas with wide directivity of each in both planes of about 15 degrees. As you can see the waveforms on figa in a moment of reflection from the object to allocate the increase in signal amplitude over the reverberation interference is practically not possible.

On figb can be seen that the signal generated by the object, is several times higher than the current level of reverberation noise. The amplitude of the interfering signal in each moment of oscillogram was determined by the signal "strongest" reflector.

The results of experimental verification of this method of reception of echo signals based on spatial-phase processing showed that the dominant interference, caused by surface reverberation, the gain in signal processing due to limitations reverb compared to conventional amplitude-time processing with the reception with one antenna 10-12 dB higher.

The device operates as follows.

Keyboard 20 PC 19 starts controlling the operation of the device the program. In the control unit 22 19 computer basis then given program formed the emitted signals with predetermined duration (1 MS), the type and frequency of filling (hue, 50 kHz), the period of radiation (0.5 sec), which through the trunk communication cable 12 is transmitted to the remote is silical radiated signals 8. The signals are amplified and through the transmitting antenna 4 are radiated into the water.

The reflected signals are taken from the water receiving antennas 5, 6 and 7 are amplified external amplifiers received signals 9, 10, 11, passed through the main communication cable 12 to the inputs of the phase detectors of horizontal and vertical direction finding reflectors 16, 17, in which at each moment of time determined by the implementation of the current angles of arrival of the reflected signals. Temporary implementation of the current angles of arrival of the reflected signals with the output of the phase detectors 16, 17 is fed to the input of the block of digital information processing 18, in which for a given program is the construction of the current density histograms of the distribution of angles of arrival of the reflected signals on the horizontal and vertical channels are calculated maxima of the two-dimensional density distribution of angles of arrival for each point in time of reception of the reflected signal. Obtained temporary implementation of the maxima for each period of radiation for a given number of periods of the radiation are averaged and stored as a threshold with which compares the calculated values of the maxima of the two-dimensional density distribution of the reflected signals for each time of admission, the results of this comparison are judged about the discovery of the underwater object. While the digital processing unit inform the tion 18 provides data visualization processing on the monitor screen 21 and output a visual graphical and numerical information on the machine-readable medium 23.

Experimental evidence of achievement the invention aims at the specific example of implementation of the method in the device detect underwater objects are represented as waveforms on figa and 3b. The waveform of the implementation of the signal figa corresponding to the change of the current value of the maximum of the two-dimensional density distribution of angles of arrival of the reflected signals at the receiving antenna of the device, illustrates the result of reducing reverberation noise in comparison with the conventional signal under the same conditions on a single value and its amplitude-time processing (see the waveform amplitude of the same Segal taken at one of the three antennas of the device on figb).

Thus, the detection of underwater objects based on the spatial-phase signal processing, separating in the plane of the front signal the effects of noise and reverberation of a reflecting object, and a device for its realization, significantly (three to four times) reduces the effects of reverberation, increasing the detection efficiency is processed underwater objects.

1. The way to detect underwater objects, according to which scuba controlled space is irradiated with acoustic signal, receive reflected from the object signals on separate foster hydrogasification, conducting survey of controlled underwater space in horizontal and vertical planes, wherein the determined at each point in time during the cycle, the radiation - receiving angles of arrival of the reflected signals in the horizontal and vertical planes by determining the phase difference between pairs of signals received by the respective pairs of receiving antennas spaced in horizontal and vertical planes of the phase centers in the plane of the front of the reflected signal, determine for each moment of reception of the current histogram density distribution of angles of arrival of the signal in both planes by determining the residence time of the observed angle of reception in each interval of angles in sectors of the characteristics of directional receiving antennas during the duration of the emitted signal, determine the maxima of the density histograms of these distributions, which by multiplication determine the current implementations of the values of the maxima of the two-dimensional density distribution of angles of arrival of the reflected signals in the plane of the front of the received signal, and in these implementations, averaged over several cycles of the radiation - receiving, guide the implementation of the current detection thresholds and in excess of the maximum of the histogram of the density distribution of the angle of arrival of the received signal to the threshold judge about the discovery of the underwater object.

2. The device for implementing the method of detecting underwater objects, including hydroacoustic equipment, characterized in that the latter is in the form of hydroacoustic pievescola system installed on the platform in the sea, including directional transmitting antenna and at least three identical and coaxial directional receiving antennas spaced apart in the plane of the front of the emitted signal in the vertical and horizontal phase centers, electrically connected with external amplifiers radiated and received signals, also mounted on the platform and connected to the main communication cable remote control installed on the shore, and containing a power supply external amplifiers, blocks of phase detectors, control and recording of electron computer (PC)that includes the block of digital information processing and control unit, monitor and keyboard, and the control unit of the PC connected to the input of the external amplifier radiated signals, outputs external amplifiers of the signals received through the trunk communication cable connected to the inputs of the phase detectors of horizontal and vertical direction finding, the outputs of which are connected to the input of the digital processing unit of the information output unit of the digital processing information associated with the monitor installed in the natural keyboard, recording and computing functions for obtaining and processing information are implemented in the system PC using daemon that runs from the keyboard, the digital processing unit information for a given program is the construction of the current density histograms of the distribution of angles of arrival of the reflected signals on the horizontal and vertical channels are calculated maxima of the two-dimensional density distribution of angles of arrival for each point in time of reception of the reflected signal received by the temporary implementation of the maxima for each period of radiation for a given number of periods of the radiation are averaged and stored as a threshold with which compares the calculated values of the maxima of the two-dimensional density distribution of the reflected signals for each reception time, the comparison results are judged on detection of an underwater object, the block of digital information processing provides data visualization processing on the monitor screen and display a visual graphical and numerical information on machine-readable media.