RU2376653C1 - Device of hydrometeorological surveys of water area of sea polygon - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention refers to stationary systems of simultaneous determination of wind velocity in water area, sea surface disturbance and dynamic underwater noise in water area, preliminary data processing, data transfer to consumer, as well as it can be used as metrological provision during adjustment (calibration) of disturbance parametre measuring instruments installed on movable sea objects and aircrafts. Device includes hydrophones 1, 2, 3, 4, 5, preliminary amplifier 6, communication line 7, wide-band amplifier 8, spectrum analyser 9, spectrum section selection unit 10, water noise classification unit 11, wind velocity determination unit 12, sea disturbance determination unit 13, synchronisation and control unit 14, satellite navigation measuring module 15.

EFFECT: enlarging functional capabilities of the device and improving accuracy during hydrometeorological surveys of water area of sea polygon.

2 dwg

Description

The invention relates to stationary systems for the simultaneous determination of wind speed in the water area, waves of the sea surface and dynamic underwater noise in the water area, preliminary processing of information, transmission of information to the consumer, and can also be used as metrological support for the adjustment (calibration) of wave parameters meters installed on moving marine objects and aircraft.

Known devices for hydrometeorological observations of the water area of a marine landfill [1, 2, 3, 4, 5, 6], as a rule, solve a specific problem, which consists in determining one parameter characterizing the current state of the environment, by instrumental recording of signals with their subsequent transmission to dispatch stations for the subsequent processing of the information received and the transmission of this information to consumers.

In the known device [1], which consists of at least two electrodes connected to a high-resistance voltmeter, the gradient of the potential of electric fields is measured, which determines the height of the waves. In this case, the registration devices are placed in the coastal zone at a depth of more than 100 m in groups and at a distance from the coastline to a distance of 4000 m and connected by communication lines to the coastal dispatch station. This device is mainly used to determine the danger of a tsunami.

The disadvantages of this device is that to ensure reliable observations in the vast water area of the marine landfill, it is necessary to place a significant number of recording devices connected by communication lines to the dispatch station, as well as a limited range of measured parameters.

In the known device [2], which is a device for measuring wave parameters from aircraft, including blocks of radiation, reception, amplification, formation and conversion of radio signals reflected from the sea surface, determining the power of the reflected signals depending on the flight altitude based on functional dependencies, heights of sea waves.

For the practical implementation of this device, in order to obtain reliable information, it is necessary to correctly select and maintain at a given level the ratio of values characterizing the flight altitude of the aircraft and the duration of the probing short pulse, which can only be achieved under favorable weather conditions, which significantly limits the use of this device for long and continuous observations of the water area of the marine landfill.

Known devices [3] are bottom stations installed from carriers to the bottom of the sea and equipped with recording equipment of a geophonic and hydrophone type for recording signals in the frequency range from 3-5 to 200-300 Hz and broadcasting them to a control station after surfacing after three weeks, for subsequent processing and determination of the functional dependencies of the parameters characterizing the environment at the installation site.

The disadvantages of these devices are low autonomy (no more than 20-30 days) and the speed of obtaining information (only after surfacing), which virtually eliminates the possibility of their use for long-term observations of the water area of the marine landfill.

Known devices [4, 5] are drifting stations (buoys) equipped with recording equipment for measuring signals characterizing the temperature and pressure of the environment, salinity and electrical conductivity of sea water, the values of which based on the functional dependencies determine the hydrometeorological parameters in the water area of the marine landfill. These stations are equipped with satellite equipment, which provides not only quick translation of the measured information to dispatch stations, but also allows you to additionally determine parameters such as current coordinates of the buoy, components of the buoy velocity vector, as well as restore the wave profile by jointly processing the current altitude and vertical speed buoy coming from a satellite navigation receiver with a second update rate based on functional dependencies with ednego sea level.

However, in order to obtain reliable parameters, it is necessary, at least, that two conditions are fulfilled due to the four satellites being within the boundaries of the polygon visibility zone with a satisfactory geometric factor and the need to restore the wave profile in the second-order filter of astatism with a smoothing coefficient α = 10 ^{- 3} and the natural frequency of the filter ω ₀ = 2π / 6. As a result of such filtering, a strongly smoothed primary wave is obtained, since secondary waves do not pass through such a filter, and then the number of wave periods over a given interval with averaging time of the measured information of at least two hours is calculated by functional dependencies.

Known devices for observing the sea surface, given in [6], are coherent radars installed on the shore, altimeters mounted on satellites, radio-Doppler meters of wave parameters installed on aircraft, as well as various types of waveographs, etc. provide a solution to a limited number of problems both in the number of measured signals and in the volume of determined parameters with the necessary accuracy and reliability, which does not allow them to be fully considered as means of objective control during hydrometeorological observations over the waters of a marine landfill, and even more so as means metrological support.

The most complete set of parameters characterizing the state of the marine landfill area is provided by a hydrometeorological observation device for the marine landfill area [7], which contains a series-connected hydrophone, a preliminary amplifier, a communication line, a broadband amplifier, a spectrum analyzer, the output of which is connected to the first input of the indicator, unit the allocation of the spectrum, the block noise classification of the sea, the unit for determining the wind speed and the unit for determining the sea waves, while the input of the unit for allocating the spectrum is connected to the output of the spectrum analyzer, and the output to the inputs of the sea noise classification unit and the wind speed determination unit, the first output of which is connected to the input of the sea wave determination unit, and the first output of the sea noise classification unit, the second output of the wind speed determination unit and the output the unit for determining sea waves is connected to the second, third and fourth inputs of the indicator, the synchronization and control unit, the controlled input of which is connected to the second output of the unit for classifying sea noise, is the first e is connected to the synchro inputs of the spectrum analyzer unit and the spectrum section allocation unit, and the second, third and fourth sync outputs are connected to the synchro inputs of the sea noise classification unit, the wind speed determination unit and the wave determination unit, respectively, which allows it to be used as a stationary system for simultaneous determination of wind speed in the water area, waves of the sea surface and dynamic underwater noise in the water area based on measured signals and functional dependences, preliminary abotki information and transmitting information on the user or dispatching station.

However, the conclusion that “the noise of shipping sharply decreases with frequency and in the selected range has little effect on the measurement results, although its influence is observed at frequencies of 5-7 kHz” does not fully correspond to reality.

For example, it is known (see, for example: 1. Sukharevsky Yu.M. Statistics of the main acoustic parameters of the deep-sea areas and the probable range of action of hydroacoustic systems. // Acoustic Journal, 1995, Volume 41, No. 5, pp. 848-864. 2. Handbook of hydroacoustics. / Evtutov A.P., Kolesnikov A.E., Korepin E.A. et al. - 2nd ed. - L .: Shipbuilding, 1988, - 552 s), that the intensity of the spectral characteristics of generalized noise decreases with increasing frequency. The maximum noise values of the marine environment are recorded in the infrasonic range (f≈1-10 Hz) and can reach 100-120 dB. In shallow areas, the noise of the individual components of the noise of the marine environment is usually 10-20 dB higher than in deep-sea. In the range of low sound frequencies (from 10 to 300 Hz), relatively coherent noise of shipping prevail (see, for example, V.I. Ilyichev Investigation of the acoustic noise field of the ocean by vector-phase methods. // Acoustics of the ocean environment. / Ed. L.M. . Brekhovskikh. - M .: Nauka, 1989. - pp. 140-152.), The intensity of which can reach 70 dB or more, while the portion of the spectrum with maximum signals can shift with increasing depth (from frequencies f = 50-100 Hz for shallow areas and up to f = 20-80 Hz - for deep water). For higher frequencies, the total noise intensity of the marine environment is determined mainly by wind speed. In the range of 1-10 kHz, the noise level of the marine environment can significantly increase (up to 55 dB) due to the noise of intense rains (see, for example, Acoustics in the Ocean. / Ed. By L. M. Brekhovskikh, I. B. Andreeva. - M .: Science. 1992 .-- 229 s).

In general, the noise characteristics of the marine environment remain stationary for implementations lasting from 10 ... 20 s to 3 ... 5 minutes (see, for example: Experimental estimates of the stationarity of underwater ocean sounds. / Aredov A.A., Dronov G.M., Okhrimenko N.N. ., Furduev A.V. // Acoustic Journal, 1994, Volume 40, No. 3, p. 357-361).

Analysis of the vertical variability of the noise of the marine environment (see, for example: Kuryanov B.M., Moiseev A.A. Investigation of the depth dependence of low-frequency ocean noise using a buoyant controlled buoyancy // Acoustic Journal, 1994, Volume 40, No. 3, p.380 -384) shows that for frequencies less than 100-200 Hz there is a tendency to increase the intensity by 3-5 dB near the axis of the underwater sound channel compared with the measurement data near the bottom. At higher frequencies, this dependence can be reversed. In particular, it was noted (see, for example, Derevyankina E.I., Katsnelson B.G., Lyubchenko A.Yu. Vertical intensity structure of the low-frequency noise field of the shallow sea. // Acoustic Journal, 1994, Volume 40, No. 3, p. 380-384), that when signals are recorded at frequencies from 200 to 600 Hz in the shallow sea (depths less than 120 m), the minimum values of the noise intensity of the marine environment are observed near the axis of the underwater sound channel. The total noise of the marine environment has anisotropy in both vertical and horizontal planes. When measured by directional hydroacoustic sensors, noise variations (see, for example: Shmarfeld B., Rauch D. Low-frequency ambient noises and noises produced by a vessel in shallow water. // Acoustics of the ocean floor. / Ed. By W. Cooperman and F. Jensen, trans. . from English., M .: Mir, 1984. - 460 pp.) in the azimuthal plane, an increase in the intensity of the acoustic signal by 4-5 dB was noted in directions to remote (1000 km) storms and areas of heavy shipping. For fields close to the observation point (up to 100 km) of hydrodynamic sources, the highest intensity was observed from directions perpendicular to the propagation of wind waves.

The absence of hydrometeorological conditions in the processing algorithms by means of an omnidirectional hydrophone located in the thickness of the marine environment at a depth of 100-150 m, taking into account the geometric factor does not allow us to determine such an important parameter as the angle of arrival of sea waves. Placing a signal recording device (omnidirectional hydrophone) at a depth of 100 m for shallow sea conditions, for ordinary conditions of an acoustic wave, due to the influence of bottom currents, can propagate at any slip angles, and their direct "capture" is unlikely.

In addition, when using the discrete Fourier transform in the sea energy noise processing algorithms, the processes under study are a superposition of harmonic oscillations in the form of a Fourier series or interval, which, for example, for analysis in hydrometeorological studies can introduce additional errors, since the sum of two periodic oscillations can be a non-periodic function, for example, when adding sinusoidal oscillations with incommensurable frequencies, when the addition of ω and 2ω gives a complex non-periodic e wobble.

The objective of the proposed technical solution is to expand the functionality of the device while increasing reliability during hydrometeorological observations of the water area of the marine landfill.

The problem is solved due to the fact that the device for hydrometeorological observations of the water area of the marine landfill, containing a series-connected hydrophone, a pre-amplifier, a communication line, a broadband amplifier, a spectrum analyzer, a unit for selecting a portion of the spectrum, a unit for classifying sea noise, a unit for determining wind speed and a unit determination of sea waves, while the input of the spectrum allocation block is connected to the output of the spectrum analyzer, and the output is connected to the inputs of the sea noise classification block and the determination block wind speed, the synchronization and control unit, the controlled input of which is connected to the second output of the sea noise classification block, the first sync output is connected to the sync inputs of the spectrum analyzer block and the spectrum section block, and the second, third and fourth clock outputs are connected to the sync inputs of the sea noise classification block, a unit for determining wind speed and a unit for detecting waves, respectively, four more hydrophones connected to a preliminary amplifier, navigation and measuring m, were additionally introduced a module connected by its inputs to the outputs of the wave detection unit, the synchronization and control unit, the wind speed determination unit, the sea wave determination unit, a spectrum analyzer, and the device is made in the form of a single monolithic structure in which the measuring units are placed, while the recessed part of the device case equipped with a polyurethane stepped frame made in the form of a truncated pyramid, in the lower part of which hydrophones are placed, four of which are oriented in parts of the world, respectively , and one hydrophone is oriented vertically towards the bottom.

The invention is illustrated by drawings (figure 1, 2). Figure 1. The block diagram of the device includes hydrophones 1, 2, 3, 4, 5, a pre-amplifier 6, a communication line 7, a broadband amplifier 8, a spectrum analyzer 9, a block for selecting a portion of the spectrum 10, a block for classifying sea noise 11, a unit for determining wind speed 12, the unit for determining the sea waves 13, the synchronization and control unit 14, satellite navigation and measuring module 15.

Figure 2. The hydrophone, which includes a signal conditioner 16, a multi-channel power amplifier 17, a pump converter 18, a driver control circuit 19, a receiving antenna 20, a low-pass filter 21, a preliminary amplifier 22, a matching device 23, a receiver control unit 24, a set of sensors 25 with a converter 29 signals from the sensors to electrical signals and a matching device 30, a computer, consisting of a computer 26 and two analog-to-digital converters 27 and 28.

The device operates as follows. Electric pump signals with pump frequencies and a given type of modulation are generated in the signal driver 16 and, through power amplifiers 17, are supplied to the pump converter 18, which emits acoustic oscillations with pump frequencies. When pump waves propagate in an aqueous medium, a parametric antenna of difference frequency waves with the necessary characteristics is formed. The operating modes of the shaper (changing the duration of the probe pulse, changing the frequency of the transmission, changing the difference frequency and the law of its modulation) are controlled by the control circuit of the shaper 19. The scattered signals as a result of the interaction of the waves of the difference frequency and hydrophysical layers are received by the receiving antenna 20, which is necessary because the emitting parametric the antenna is irreversible, and the pump at the differential wave frequency has a low sensitivity due to operation away from resonance. Electrical signals through a low-pass filter 21, in which pump waves are suppressed, are fed to a pre-amplifier 22 and then to a matching device 23, which is designed to match the input and output impedances of the amplifier and the analog-to-digital converter of the satellite measuring module 15. The gain of the receiving part, the passband depending on the type of signal and the duration of the pulse is controlled by the control device of the receiving part 24. The set of sensors 25 contains salinity sensors, eratury and pressure transducer located at the pump and designed to measure the parameters of the aqueous medium in the zone of interaction of the pump waves that are needed in the future for the calculation of the difference frequency changes of the signal wave along the path of propagation. The calculations are made for the reasons that the generation of signals of difference frequency waves occurs in space and their levels cannot be obtained by bringing to a normalized level at a certain distance, as is done in traditional emitting antennas, and also because the levels depend on values of medium parameters in the zone of interaction of pump waves. The signals from the sensors are converted into electrical signals in the signal converter from the sensors into electrical signals and through the matching device are fed to an analog-to-digital converter 27 of the calculator. The computer 26 controls the analog-to-digital converters 27, 28 and performs all the calculations to determine the profiles of temperature, salinity, acoustic resistance, sound velocity and density of the medium with inhomogeneities.

The determination of the parameters of the layers of hydrophysical inhomogeneities is carried out in a complex by computing them in the following sequence.

The signals from the receiving antenna and the set of sensors through the corresponding analog-to-digital converters are sent to the computer, where they are processed in the part of preliminary processing, in which the amplitudes of the reflected signal and the probing signal are calculated at the installation site of the receiving antenna, the coordinated processing of the received signals to accurately determine the position scattered signals and determining various moments of the signals, analyzing the correlation of signals, calculating the reflection coefficients of the layers, forming the initial data of hydrophysical characteristics at the place of installation of the pump transducer, calculation of the characteristics of the probe signal along its propagation path, which is necessary to calculate the true value of the amplitude and phase of the differential frequency wave incident on the scatterer, calibrate the probe signal measured at the place of installation of the pump transducer, and calculate the acoustic impedance of layers, calculation of layer depth, layer thickness and speed of sound in it, calculation of layer density, formation of temperature profiles tours, salinity, acoustic impedance, density and sound velocity, calculating the temperature and salinity layers.

The use of such processing allows, knowing the hydrophysical parameters of the layer located at the pump transducer, to calculate successively layer by layer the parameters of the remaining layers.

Hydrophones 1, 2, 3, 4, 5 have the following characteristics: operating frequency range 15-50 kHz, pump wave frequency 125.5-148 kHz and 153-175.5 kHz. The type of emitted signal is a rectangular radio pulse, a linearly frequency-modulated pulse signal, a signal with a tunable frequency from pulse to pulse, the duration of the probe pulse is 1, 2, 4, 8, 16, and 32 ms, the pulse repetition rate is not more than 2 Hz.

The unit for determining the sea waves 13 is a microprocessor device consisting of an analog-to-digital converter, controller, random-access memory, programmable memory, suboptimal filter.

The measurement of the wave profile is based on the integral method based on the indirect determination of the wave profile based only on the data on the vertical velocity of the device on the water surface in accordance with the dependence

, где

where

S is the movement of the device during time T;

V (t) is the speed of movement of the device.

The movement of the device at a particular moment is determined by the formula

где

Where

S (t) - the current position of the device;

S ₀ - the position of the device at the previous moment;

and - acceleration.

This method allows you to completely exclude rough height measurements from processing and get information about drifter movement only from high-precision speed data.

To exclude highly noisy code measurements of height by phase velocities of drifter movements, a suboptimal filter is used. The current estimate of Z _i using any linear filter as the sum of the forecast Z _i and the filtered estimate of the current measurement:

,

,

- текущее значение измерения;Where

- current measurement value;

α - transmission coefficient, determines the filter time constant α = 1τ _s ;

Since the Z estimate is formed in satellite receivers from high-precision phase measurements that reproduce drifter dynamics with millimeter (submillimeter) accuracy, formula (2) determines the most accurate forecast for any linear satellite measurements filter. Substituting (2) in (1), we obtain an α - IIR filter, which optimally smooths phase measurements of code measurements:

.

.

The result of processing are optimally smoothed code measurements, however, this filter cannot remove the constant low-frequency trend of errors in high-altitude measurements, due to a sufficiently large value of α. To eliminate this trend, it is sufficient to apply the same filter repeatedly to an already smoothed estimate, but with a large coefficient α (deep smoothing). Analysis of low-frequency noise allows us to conclude that the choice of α = 0.15 1 / s will be a compromise. Next, centering is performed (subtracting from the trend estimate). After trend exclusion, the variance of the obtained centered estimate is calculated:

where H _i are the values of the centered trend,

N is the number of values in the sample.

, где А - искомая амплитуда, σ - средняя квадратическая ошибка.The amplitude of the oscillations is derived through the dispersion

where A is the desired amplitude, σ is the mean square error.

Next, the period of the waves is calculated by counting the number of intersections by the zero line wave profile.

Moreover, by means of a satellite navigation system of the type SN-3800, the velocity vector of the flow of the water surface is determined by the change in the horizontal movement of the drifter.

The wave height h _i is defined as h _i = r ₁ + r ₂ , where r ₁ is the height of the previous half-period, r ₂ is the height of the subsequent half-period. If there are several identical maximum amplitudes for a half-period, any of them is used to calculate the wave height. After determining the values of the wave heights and their number in the implementation, the average value of the wave height is calculated

, где m - число волн за время измерения 20 минут.

where m is the number of waves during the measurement time of 20 minutes.

To determine the wave height of 3% of coverage, 20 maximum waves are selected from the array of wave heights, which are arranged in decreasing order of 1 to 20, starting with the maximum amplitude. Then the index of 3% security K _3% = 3m / 100 is calculated. The wave height corresponding to this index will be three percent. The collection and processing of measured information is carried out in a satellite measuring module 15, consisting of a controller, including RS232 interfaces - up to 8 channels, EPP / ECP 1 channel, parallel to the 8-bit bus 12 channels, power control line of external devices 5/12 V, up to 0.5 A - up to 8 lines, SPI up to 3 channels, 12S - up to 2 channels, CAN channel, USB-1 channel, ultrasonic channel 1, fiber optic modem 1, radio modem 1, FLASH memory up to 4 GB, real time clock , analog channel input filters.

The drift drift velocity V (t), determined by the satellite navigation system, is nothing more than the drift drift velocity Vd of drifter movement, which is defined as Vd = (0,0127 / √ sinφ) W, where φ is the latitude of the place, W is the speed wind (see Shuleykin VV Short course of sea physics. L .: Hydrometeorological publishing house, 1959, p.40). From where the wind speed can be defined as W = Vd / 0,0127√sinφ, which is carried out by means of the unit for determining the wind speed 12.

Analogues of blocks 6, 7, 8, 9, 10, 11 and 14 are similar blocks of the prototype. The device as a whole is made in the form of a single monolithic structure in which the measuring units are located. In the upper part there is a cover used to install measuring units. A satellite navigation antenna is mounted on the lid. The recessed part of the body is equipped with a polyurethane stepped frame made in the form of a truncated pyramid, in the lower part of which there are hydrophones, four of which are oriented in parts of the world, respectively, and another hydrophone is oriented vertically towards the bottom. The stepped frame, expanding downward with hydrophones installed on it, serves as a stabilizing device and serves to dampen vibrations of the device as a whole.

The technical result, which consists in increasing the reliability during hydrometeorological observations of the water area of the marine landfill and in expanding the functionality of similar devices, is achieved due to the fact that four more hydrophones connected to the preliminary amplifier are additionally introduced, a navigation and measuring module connected to its inputs and outputs of the unit determination of waves, synchronization and control unit, unit for determining wind speed, unit for determining sea waves, analyzer krat, and the device is made in the form of a single monolithic structure in which the measuring units are placed, while the recessed part of the device case is equipped with a polyurethane stepped frame made in the form of a truncated pyramid, in the lower part of which hydrophones are placed, four of which are oriented in parts of the world, respectively , and one hydrophone is oriented vertically towards the bottom.

The industrial implementation of the proposed technical solution does not present technical complexity, as it uses commercially mastered products and proven hardware.

Information sources

1. RF patent No. 2066466.

2. RF patent No. 1240169.

3. Modern bottom stations for seismic exploration and seismological monitoring. / Zubko Yu.N., Levchenko D.G. Ledenev V.V., Paramonov A.A. // Scientific Instrumentation, 2003, volume 13, No. 4, p. 70-82.

4. High-precision water-level monitoring / Massatoshi Harigae, Isao Yamaguchi, Tokio Kasai, Hirotaka Igava, Hiroto Nakanishi, Takahiro Murayama, Yasunori Iwanaka, Hirotaka Suko // GPS World, April 2005.

5. Patent US No. 6847362 B2, January 25, 2005.

6. Zagorodnikov A.A. Radar survey of the sea surface from aircraft. L., Shipbuilding, 1978, 376 p.

7. RF patent No. 2079168 C1.

Claims (1)

A device for hydrometeorological observations of the water area of a marine landfill, containing a serially connected hydrophone, a pre-amplifier, a communication line, a broadband amplifier, a spectrum analyzer, a unit for selecting a portion of the spectrum, a unit for classifying sea noise, and also containing a unit for determining wind speed and a unit for determining sea waves, a synchronization unit and control, the controlled input of which is connected to the second output of the sea noise classification unit, the first sync output is connected to the sync inputs of the analyzer unit spectrum and block selection of a portion of the spectrum, and the second, third and fourth clock outputs are connected to the synchro inputs of the block for classifying the noise of the sea, the unit for determining the wind speed and the unit for determining the sea waves, respectively, characterized in that four additional hydrophones connected to the preamplifier are introduced, navigation -measurement module connected by its inputs to the outputs of the synchronization and control unit, the unit for determining the wind speed, the unit for determining sea waves, the spectrum analyzer.

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