Apparatus for determining corrections to depth measured by echo sounder when mapping bottom topography of water body

FIELD: physics.

SUBSTANCE: apparatus has a multibeam echo sounder 1, a recorder 2, a control unit 3, a unit for determining corrections 4, a measuring receiving unit with an antenna 5, a transmitter with an antenna 6, sensors for measuring sound speed 7, 8, a measuring receiving unit with an antenna 9, a transmitter with an antenna 10, water temperature sensors 11, 12, hydrostatic pressure sensors 13, 14, a relay 15, a communication channel 16 of a satellite radio navigation system, horizontal and vertical displacement sensors 17, a magnetic compass 18, a stabiliser gyrocompass 19, a hydroacoustic communication channel 20, a relative velocity metre 21.

EFFECT: high accuracy of determining corrections.

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The invention relates to research bathymetric field waters by registering depths through sonar.

Known methods and devices for research bathymetric field on the waters[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11].

In the known methods for determining amendments sonar associated with the spatial heterogeneity of the speed of sound in water at depths up to 30 m (according to the regulations on the shooting of bottom topography), it is necessary to perform complex and time-consuming step is the calibration of the echo sounder special chairwomen device. This operation must be done at least twice a day (at the beginning and at the end of shooting) to determine amendments sonar. In waters with depths greater than 30 m should be measured at the hydrological stations of temperature, salinity and water pressure or the velocity of propagation of sound in water by a special meter to determine the corrections for the deviation of the actual speed of sound in water from the settlement and for the refraction of the acoustic beam sonar.

When the calibration of the echo sounder need to stop shooting and move to the area, shooting with the greatest depths, where when the ship is at anchor or drift to carry out immersion (upgrade) ship-control boards (ROM), or the receiving of the vibrator tariro the feeder into the working area of the radiating the transducer 10 fixed horizons of calibration. The error in the determination of the amendments sonar by this method due to the disregarding of the bending of the rope under the influence of immersion vibrator or tarious Board (drive) current and drift of the vessel and eye depth horizon of the calibration label on the cable can be 1-4% [1].

To determine with certainty amendments for changes in precipitation vessel in shallow water (sinking ship), you must perform a relatively large number of runs of the carrier vessel sonar at different depths, at different speeds and at different draught of the vessel in order to obtain data for the compilation of tables or nomograms.

In addition, you must define a group of instrumental corrections to the measured sonar distances to the bottom, the definition of which is also characterized by great complexity and laboriousness. Calibration measured by the sounder inclined distances performed by comparing the depth values measured by the Central and side beams of sounder at identical points in the zone stripes examination of the intersecting lines [2]. As distances measured Central probe beam, contain most of the above errors, and an exact match of reflection points on the bottom, to which the measured distance of the Central and side beams, it is almost impossible, it is not ensured Costigan the e desired level of precision shooting bottom relief.

In the depths of the waters of more than 30 m amendment sonar is calculated as the sum of private corrections resulting from accounting for certain errors: corrections for the deviation of the actual speed of sound in water from the calculation, the correction for refraction corrections for the deviation of the rotation frequency of the motor nominal corrections for the location of the zero depth sounder, corrections for the deepening of vibrators, corrections for inclination of the bottom.

Improving the accuracy of survey bathymetric field offshore provides a method of determining amendments to depths, measured single-beam survey echo sounder when taking relief of the bottom waters, and the device for its implementation [12], which includes immersion up to a given horizon or to the bottom surface, and then rise to the surface waters, vertically holding the base with a known length b and located at the lower end of the base priekaistaudami vibrator (pievescola antenna) single-beam sonar with radiation and reception of acoustic signal vertically to the surface of the waters, and hydroacoustic sensors pressure and temperature, and on the upper end of the base second hydroacoustic sensors pressure and temperature.

While synchronously measured hydrostatic pressure and temperature on the upper and lower ends of the base fixing is fixed by the temperature correction of the measured values of hydrostatic pressure andmeasured by hydroacoustic depth priekaistaudami vibratorand the true meaning of correctionsdetermined by calculation based on the formula dependencies:

;

;

;

,

where i (i=1, N) parcel number emitting vibrator, starting from the moment of immersion of the upper end of the base and to reach the upper end of the base when lifting surface waters;

,- hydrostatic pressure, synchronously modified k-th parcel sonar sensors hydrostatic pressure respectively on the upper and lower ends of the base and corrected by the correction for temperature, starting from the moment of immersion of the upper end of the base and to reach the upper end of the base when lifting surface waters;

,- hydrostatic pressure, measured respectively hydrostatic sensor, located on the lower end of the base, when the k-th and (k+1)-th sending an acoustic signal to the surface waters, and are corrected by the correction for temperature, since momentarily upper end of the base and to reach the upper end of the base when lifting surface area;

δz_i- amendment of the depth of the horizon tare (dipping priekaistaudami vibrator single-beam echo sounder).

The method is implemented in the form of tiraumea devices [12], which contains:

transmitter and measuring a receiving unit, connected respectively to priekaistaudami the vibrator;

- base on the positive and negative buoyancy, mounted in gimbals, dipped for a given horizon of calibration and raised to the surface waters in the vertical position;

- relays, sensors, hydrostatic pressure and temperature, mounted on the upper end of the base;

- hydrostatic pressure sensors, temperature and priekaistaudami vibrator with radiation acoustic signal to the surface waters and vertical receive reflected from her signal, mounted on the lower end of the base;

- the control unit, the definition block of the amendments to depths, measured by the sonar logger.

Relay outputs, sensors, hydrostatic pressure and temperature, measurement of the receiving unit via the control unit is connected to the input unit of determining the corrections to the measured depth sounder, the output of which is connected to the input of the logger.

Evaluation of the accuracy of amendments to depths, measured by the sonar data in the manner and chairwomen device the PTO is calculated as follows [12]:

where σ_Δz- RMS determine amendments to depths, measured by the sounder;

σ_P- RMS measurement of hydrostatic pressure sensor;

φ is the latitude of the place of calibration;

P₁P_z- hydrostatic pressure in decibar, measured respectively on the first and the horizon again.

For the case when the UPC modern serial sensors hydrostatic pressure is 0.05 Dbar [1], the error in the determination of the corrections to the measured echo sounder depth of the proposed method using tiraumea device when the depths of the horizon up to 200 m 0.1 m regardless of the horizon again. Given index in the proposed method [12] - 2 times higher than known methods and hareruya devices [1,2], where the error due to the curvature of the cable, which is at a depth of horizon 40 m reaches 4% of the depth.

The positive effect of the way and tiraumea device for determining the corrections to the measured depth sounder is to increase accuracy by identifying amendments sensors hydrostatic pressure and water temperature. The drawback of this method and tiraumea devices is the inability to use, to determine amendments to depths and geodetic coord. there, the measured digital multibeam echo sounder in the band of his probing.

Use the cable to hold tiraumea device limits the range of depths, and therefore the maximum horizon determine the corrections, which is limited by the length of the cable.

In addition, analysis of the identified sources of information showed that there is currently no way and tiraumea device for determination of the amendments to depths and their geodetic coordinates, measured in-band sensing multibeam echo sounder on the waters of the shooting, and therefore, there is no metrological support, allowing the unity of measurements at the shooting of the bottom topography by multi-beam echo sounders on the waters of the shooting, which significantly reduces the reliability of objective information.

The objective of the proposed technical solution is to increase the reliability of the amendments in the measurement of depth through the use of multibeam sonar.

This goal is achieved due to the fact that the device for implementing the method that contains the transmitter and measuring the receiving unit, connected respectively to the radiating and receiving antennas, the Registrar and the control unit connected to the measuring receiver unit, base with positive and negative buoyancy, with the possibility of the awn of its descent at a given horizon of calibration and rise to the surface of the water in a vertical position, at the upper end of which is fixed perceiving the relay contacts, acting contacts which are connected with the control unit, together with the radiating antenna, receiving antenna and sensors hydrostatic pressure and temperature on the lower end of the base and sensors hydrostatic pressure and temperature on the upper end of the base, which outputs via a control unit connected with the input of block definitions amendments to depths, with the possibility of radiation acoustic signal to the surface vertically and receive reflected from her signal block definition amendments to depths, measured by the sounder, the entrance through which the control unit is connected to the output premoistening unit, and the output connected to the input of the Registrar on the upper end of the base antenna is installed receiver satellite navigation system, at the lower end of the base posted by radiating and receiving antennas with radiation hydroacoustic signals across multiple rays to the surface of the bottom of the water area in the vertical and reception of reflected her signals for Central and inclined beams, sensors horizontal and vertical displacements of the held base and the sensor measuring the speed of sound, meter relative velocity, magnetic compass and gyroazimuthcompass-compass mounted in a cardan suspension, satellite R is geonavigation and hydroacoustic communication connected to the control unit, and the negative buoyancy made in the form of concrete sectional ballast, which is coupled to a vertical base by its radius by step sling with electrochemical breakers.

The invention is illustrated by drawings.

Figure 1 - Block diagram of the device. The device comprises a multibeam sonar 1, the recorder 2, the control unit 3, block definitions amendments 4, measuring a receiving unit with an antenna 5, a transmitter with an antenna 6, a sensor measuring the speed of sound 7, 8, measuring a receiving unit with an antenna 9, a transmitter with an antenna 10, a temperature sensor water 11, 12, hydrostatic pressure sensors 13, 14, the relay 15, the communication channel 16 satellite navigation systems, sensors horizontal and vertical displacements of 17, the magnetic compass 18, the pitch gyro-compass 19, hydroacoustic communication channel 20, the probe relative speeds of 21.

Measuring the receiving unit with the antenna 5 and the transmitter 6 to the antenna perform the same functions as in the prototype [12]. Measuring the receiving unit with the antenna 9 and the transmitter with the antenna 10 respectively generate and receive acoustic signals by five rays (one Central and four lateral rays). Figure 2 is a vertical base. Vertical base 22 is made in the form of a cylinder in the upper part of which lies the germ which ranks capacity 23 to provide positive buoyancy. In the lower part of a vertical base on the outer surface of the radius is negative, made in the concrete structure 24 to provide negative buoyancy and fixed to the body vertical base through sling 25, in which the place of articulation of the concrete structure is made in the form of sections 26, equipped with electrochemical breakers 27. The concrete structure 24 is made in the form of plates 28 covered by sections 26 sling 25. Within a vertical base 22 on gimbals 29 mounted magnetic compass 18 and gyroazimuthcompass-compass 19. On the inside walls and shelves 30 vertical base 22 are sensors measure linear and angular velocities and accelerations 17. On the inner shelves are installed, the control unit 3, the recorder 2, the measuring and receiving unit 5, a transmitter 6, a block definition amendments 4, channel hydroacoustic communication 20, antenna 31 which is installed on the upper surface of the vertical base 22, the channel of the satellite radio navigation links 16, antenna 32 which is installed on the upper surface of the vertical base 22, on the upper surface of which is also equipped with measuring the receiving unit with the antenna 5 and the transmitter with the antenna 6. In the vertical wall of the base 22 are electrodes 33 measuring the relative speed is 21, the measuring unit 34 which is mounted on the shelf 30. Also on the vertical wall of the base 22 in the upper and lower parts placed sensors water temperature 11, 12 and hydrostatic pressure sensors 13, 14. Relay 15 is placed in the upper part of the vertical base 22. Measuring the receiving unit with the antenna 9 and the transmitter with the antenna 10 is placed on the bottom surface of the vertical base 22. Figure 3 - sensor measuring the speed of sound 7 consists of a radiating transducer 35, the receiving transducer 36, a pulse generator 37, amplifier 38, a frequency discriminator 39, the frequency divider 40, the generator voltage controlled 41, sea water 42.

The sensor measuring the speed of sound 7 is closed through the sea water 42 acoustic ring synchronization, formed radiating transducer 35 and the receiving transducer 36, amplifier 38 and a pulse generator 37 is triggered by the output signal of the amplifier 38. The pulse frequency in this ring is proportional to the speed of sound in water. In the frequency discriminator 39 this repetition rate is compared with the frequency radiated by the transmitter antenna 6 and 10. Frequency discriminator 39 is a harmonic signal in the ring. When you change the speed of sound in water at the output of the frequency discriminator 39 receive the control voltage and the and that sign, modify accordingly the frequency emitted by the transmitter 6 or transmitter 10 signal. This automatically is maintained constant, the wavelength of the oscillations emitted by the vibrator. The sensors measure the speed of sound 7 and 8 are designed for the direct measurement of the speed of sound on the horizons of the transmitters 6 and 10, respectively.

Radiating 35 and 36 receiving transducers each sensor measuring the speed of sound installed respectively on the top and bottom of the vertical plane of the base 22 and the blocks 37, 38, 39, 40, 41 within a vertical base 22 on the shelves 30.

Similar sensor measuring the speed of sound 7(8) is given in the source: Marine velocimeter // ed Khrebtov A.A. - M.: Transport, 1978, p.132-133.

Measuring the relative speed 21 is an induction meter speed, analogues of which are described in the source: Marine velocimeter // ed Khrebtov A.A. - M.: Transport, 1978, p.47-68. Measuring the relative speed of 21 designed to determine the module of the vector of the relative velocity, vertical base 22 of the corner of her drift during descent and ascent.

The essence of the proposed method and device for its implementation is as follows.

Before taking a picture of the bottom relief in the waters of the chosen space to perform the calibration of the echo sounder, in which the ship set is poured to anchor or left in the drift.

By ship tripping device vertical base 22 is lowered over the side into the water with regard to transmitting antenna 31 satellite radio navigation channel 15 remained above the surface. The signals from the ship measuring complex initiate control unit 3 and the communication channel of the satellite radio navigation system, which determine the initial coordinates of the vertical base 22. Then continue the descent vertical base 22 and at the moment of contact with water of the receiving relay contacts 15 Executive relay contacts close in the control unit 3 of the electric circuit forming pulse start transmitters 6, 10 and multibeam echo sounder 1. Simultaneously the signals from the measuring vessel of complex acoustic communication channel 20 signals to the control unit 3 to start in the other measurement tools. Through the mechanisms of the ship tripping device vertical base 22 is lowered to the predetermined depth and measure the signals recording for 3 to 5 levels in depth. Then release the vertical base from holding her rope, and she is under the effect of negative buoyancy begins to sink toward the bottom. In the process of immersing a vertical base measurement near the STI distribution of sound distances to the bottom and surface waters relative velocity and angle of drift during descent and ascent vertical base, rate, pitch and roll, the linear and angular velocities and accelerations, water temperature and pressure. The measured values for channel acoustic communications are broadcast in the ship measuring system, which when reaching the bottom of the vertical base to the control unit 3 sends the signal to the ascent. With the control unit 3 a signal to the electrochemical breakers 27. The breakers electrical signal, under which the electrochemical breakers are dissolved in sea water, while relieving the lines 25, which in turn release plate 28. Plates 28 are released from the sling gradually, which allows you to slow the ascent vertical base 22. When the vertical ascent of the base 22 to the surface via a satellite radionavigation system determine its coordinates. In the process of ascent are also measurements.

On the obtained arrays of measurements made when submerged vertical base to the bottom, when its on the bottom and in its ascent to the surface determines the amendments again.

Through the receiver to the satellite radio navigation systems such as GPS or GLONASS" in moments of immersion and split the vertical base 22 define the geodetic coordinates of x _0n, y_0nand x_0b, y_0brespectively. When processing signals received by gyroazimuthcompass-compass, magnetic compass, measuring the relative speed sensors linear and angular velocities and accelerations determine the current geodetic dead-reckoned coordinates,roll α, pitch φ, the azimuthAnddirection of the strip sensing acoustic signals to the surface waters pievescola antenna multibeam echo sounder, speed of sound propagation in the water in the area of distribution of this antenna. Determine on the horizon i for each j the beam depthpievescola antenna and its geodetic coordinates,acoustic means, and then calculates the desired value of the amendments to depthsand their geodetic coordinates,for the i-th horizons band multibeam echo sounding formulas.

For the Central beam:

;

;

,

whereis calculated by the formula;

;

img src="http://img.russianpatents.com/1117/11174174-s.gif" height="14" width="83" /> ;

,

where i (i=1, N) parcel number signals, starting from the moment of immersion of the upper end of the base and to reach the upper end of the base when lifting surface waters;

,- hydrostatic pressure, synchronously modified k-th parcel sonar sensors hydrostatic pressure respectively on the upper and lower ends of the base and corrected by the correction for temperature, starting from the moment of immersion of the upper end of the base and to reach the upper end of the base when lifting surface waters;

,- hydrostatic pressure, measured respectively hydrostatic sensor, located on the lower end of the base, when the k-th and (k+1)-th sending an acoustic signal to the surface waters, and are corrected by the correction for temperature, starting from the moment of immersion of the upper end of the base and to reach the upper end of the base when lifting surface waters;

δz_i- amendment of the depth of the horizon tare (dipping pievescola antenna single-beam echo sounder), andandare calculated by the formulas:

where k and N is the number of differences,up to a given horizon or to the bottom and surface waters, respectively.

For oblique rays:

where,,- amendments to the depth pievescola antenna multibeam echosounder and its geodetic coordinates of the locations reflected sonar signals on the horizon i by ray j from surface waters;

,,the true (reference) depth to first horizon and geodetic coordinates in places reflect the sonar signals from surface waters radiated pievescola antenna to the j-rays, respectively, defined by multibeam sonar.

The value of each of the depthswell depthbecause pievescola antenna is located on the lower end of the immersed base and oriented in the first horizon, emits acoustic signals on the j-rays until smooth bottom surface and receives echo signals at the first horizon j beam at the location of the antenna.

andare determined by the expressions:

whereand- the increment to the true geodetic coordinates on the first horizon center pievescola antenna located at the end of the base, reflect sonar signals from surface waters by j-rays, respectively.

andcalculated by the formula:

where θ_ij- the angle between the axis of the Central beam pievescola antenna oriented vertically on the first horizon and the direction of reception of the reflected acoustic signal from the surface waters by j ray.

The angle θ_ijfor a sounding Board is calculated by the formula:

θ_ij=180°+θ_ij,

and for beams starboard by the formula:

θ_ij=180°-θ_ij

The angle θ_ijis calculated by the formula:

,

where φ_d- phase shift hydroacoustic signal received two adjacent antenna elements sonar;

ν_Titov- the speed of propagation of sound in water at the surface pievescola antenna located at the end of the base;

f - frequency sonar signal;

d is the length of the base between adjacent sensors priekaistaudami vibrator multibeam echosounder;

α is the roll angle;

δ - constructive angle formed by the vertical and normal to the base between adjacent sensors pievescola antenna multibeam echosounder.

To evaluate the accuracy of the determination of the true corrections to geodetic coordinates of the measurement location, depth, measured by multi-beam echo sounder, can be produced as follows from the analysis formulas to determine the corrections. Thus accept the hypothesis that the expression under the sign of the sum in the right parts are not burdened by the constant and systematic components of error, since the increments of the given errors are practically eliminated, and random instrumental error in the modern multibeam echo sounders small in size and have different signs, and therefore, when a large number of measurements of a random error under the sign of the sum will tend to zero. Therefore, the error in the determination of geodetic coordinates will be almost equal to the error of determination of geodetic coordinates of the receiver to the satellite radio navigation systems like GPS, which is in differential mode 10 see

Use the La definition amendments to depths, measured by the sounder when taking relief of bottom waters for the production of measurement and recording of amendments to the measured multibeam echo sounder depths and their geodetic coordinates, provides a measurement of depths and their geodetic coordinates when you are shooting a bottom relief in the waters of the World ocean with the required accuracy because it provides accurate measurement of the vertical gradient of the depth hydrostatic pressure measured by sensors hydrostatic pressure at each horizon of calibration due to synchronously measured parameter on the basis of known length, and determining the precise incrementation parameter for each horizon calibration by calculating the difference of the following after a short period of time samples of the parameter measuring the speed of the sound horizon antennas in a wide range of measured depths in the calibration process works.

Performing these procedures provide exception of constant systematic errors of measurement increments of distance or increment of hydrostatic pressure.

The proposed method provides increased depth of calibration and getting depth calibration with normalized metrological characteristics.

Industrial applicability of the proposed method and device DL is its implementation of technical difficulties does not represent, since their implementations can be used commercially developed instrumentation and software.

Sources of information

1. Volkov, A.E., Kaloshin A.I. and other guidance on the use of sonar navigation systems to determine the location of the vessel and underwater technical means at performance marine exploration // CGFU NPP for marine geological prospecting. St. Petersburg, 1998.

2. Dadashev A.A. Calibration of multibeam echo sounder on intersecting lines. // Notes on hydrography. - 2000. No. 251, pp.42-46.

3. Patent RU No. 2123191 C1. Running from 10.12.1998.

4. Patent RU No. 2045081 C1. 27.09.1995.

5. SA SU # 472315 A1. 30.05.1975.

6. SA SU # 100803 A1. 01.01.1955.

7. AC SU # 1829019 A1. 23.07.1993.

8. SA SU # 1838802 A3. 30.08.1993.

9. The US patent No. 4916674 A. 10.04.1990.

10. Patent DE No. 3438045 A. 23.05.1985.

11. Patent EP No. 0106205 A. 25.04.1984.

12. Patent RU No. 2292062 C2. 20.01.2007.

The device for determination of the amendments to depths, measured by the sounder when taking relief of the bottom waters containing the transmitter and measuring the receiving unit, connected respectively to the radiating and receiving antennas, the Registrar and the control unit connected to the measuring receiver unit, base with positive and negative buoyancy, with the possibility of descent for a given horizon of calibration and rise to the surface of the water in an upright position on the upper end of which is fixed the perceiver relay contacts, acting contacts which are connected with the control unit, together with the radiating antenna, receiving antenna and sensors hydrostatic pressure and temperature on the lower end of the base and sensors hydrostatic pressure and temperature on the upper end of the base, which outputs via a control unit connected with the input of block definitions amendments to depths, with the possibility of radiation acoustic signal to the surface waters and vertical receive reflected from her signal block definition amendments to depths, measured by the sounder, the entrance through which the control unit is connected to the output premoistening unit, and the output connected to the input of the Registrar, characterized in that on the top the end of the installed base of the antenna of the satellite radio navigation and sonar communication at the lower end of the base is placed receiver with antenna and priekaistaudami unit with an antenna having a radiation hydroacoustic signals across multiple rays to the bottom surface waters and vertical reception of reflected data signals for Central and inclined beams, sensors horizontal and vertical displacements of the held base, the sensor measuring the speed of sound in water, the sensors of the horizontal and vertical movements of held-base meter relative soon the tee, the magnetic compass and gerasimovskaya, mounted on gimbals, satellite radio navigation and sonar communication, which are connected to the control unit, and the negative buoyancy made in the form of concrete sectional ballast, which is coupled to a vertical base by its radius by speed lines equipped with electrochemical breaker.