RU2239175C1 - Hydrological device for definition of depth of occurrence of a jump in a full-scale reservoir - Google Patents

Abstract

FIELD: hydrology and hydroacoustics.

SUBSTANCE: the invention presents a hydrological device for definition of depth of occurrence of a jump in a full-scale reservoir, that may be used in hydrology and hydroacoustics. The technical result is reception on the output of the device having one mainframe of the optical signal bearing the direct information on a depth of an occurrence of a jump layer in the full-scale reservoir. The hydrological device contains: depth sensors and a density gradient of sea-water incorporated in the uniform cage and a weight clutch - all fixed on a wire rope of a winch, located on the above water platform; a tool for reading of depth of the reservoir and a registering device. At that the sensors of depth and gradient of density of sea-water present a coherent light source with a photodetector optically matched through two fiber reels to an interferometer. At that they add additionally a multiplier and an amplitude-limiting amplifier with its input connected to an exit of the photodetector, and the tool for reading of depth is made as the frequency meter-periodometer, input of which is connected to the output of the amplitude-limiting amplifier and an output - through the multiplier to the registering device.

EFFECT: the invention allows to receive direct information on a depth of an occurrence of a jump in a full-scale reservoir.

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Description

The invention relates to the field of hydrology and hydroacoustics and can be used to determine the depth of the jump in a natural reservoir.

The most important hydroacoustic parameter of the ocean is the speed of sound, which increases with increasing water temperature, salinity and pressure. The first two parameters are stratified vertically, which leads to the fact that the speed of sound is also stratified by the depth of the natural reservoir.

Near the sea surface is the so-called "mixed layer" of water, the speed of sound in which is practically isotropic. Below the mixed layer lies the “thermocline” (jump layer), in which the temperature rapidly decreases with increasing depth.

Below the thermocline is a region of constant temperature.

Since the speed of sound increases with depth along the upper boundary of the isothermal region (lower boundary of the thermocline), there is a minimum in the sound velocity profile. This minimum is the depth of the axis of the underwater sound channel, inside which, due to refraction, sound energy is concentrated to one degree or another [1].

The presence of a jump layer in a natural reservoir exerts a great influence on practical sonar acoustics, making it possible, on the one hand, to use the natural “sound channel” in the ocean for further sonar communication, and, on the other hand, to use the jump layer as an “underwater barrier” for the sound of enemy sonars [2].

For the effective use of the hydroacoustic properties of the jump layer, it is necessary to know the depth of its occurrence in a natural reservoir.

Known hydrological device for determining the depth of the layer of the jump in the natural reservoir [3], adopted as a prototype.

The prototype, referred to in the source [3], as a bathothermograph, contains depth and gradient sensors of sea water combined in a single housing, as well as a weighting clutch mounted on a winch cable located on a surface carrier. There is also a readout device for the depth of the reservoir and a recorder.

The batithermograph prototype is a marine hydrological device that allows for simultaneous measurements and recording of the temperature and depth of a reservoir. The prototype allows the calculation of vertical temperature gradients and their recording as a function of the depth of the natural reservoir.

A bathtermograph consists of two main parts: a thermoblock that records temperature changes, and a bathiblock that shows depth. The movement of these two blocks of the device is combined into one movement of the pen of the recorder, recording the change in temperature with the depth of the reservoir.

The disadvantage of the prototype is the need for two blocks in the composition of the device, the need to process the measurement results to determine the depth of the jump layer and the electrical (rather than optical) nature of the output signal.

The technical result obtained from the implementation of the invention is to eliminate these disadvantages of the prototype, i.e. receiving at the output of the device having one main unit, an optical signal carrying direct information about the depth of the jump layer in a natural reservoir.

This technical result is obtained due to the fact that in a known hydrological device for determining the depth of the jump layer in a natural reservoir, containing depth and gradient sensors of sea water combined in a single housing, as well as a weighting clutch mounted on a winch cable located on an underwater carrier , a reference device for the depth of a reservoir and a recorder, depth and density gradient sensors for sea water are made in the form of a coherent light source and a photodetector, optically matched x through two fiber coils into the interferometer, in addition, a multiplier device and a limiter amplifier connected to the photodetector input are added, and the readout device is made in the form of a frequency counter-periodimeter connected by an input to the output of the limiter amplifier, and the output through the multiplier device to to the registrar.

The device may further comprise a phase-shifting device installed in one of the fiber coils. Moreover, as a winch cable, a cable cable based on a fiber communication line can be used.

The fiber coils of the interferometer are configured to change the distance between them.

Moreover, the fiber coils with a phase-shifting device are located in the device’s case, and the coherent light source, photodetector, limiter amplifier, periodimer frequency counter, multiplier and recorder are on an underwater carrier.

The device may further comprise a sensor for starting the immersion of the device connected by the output to the input of the frequency meter-periodimer.

In this case, the sensor of the start of immersion of the device can be installed on the winch.

The invention is illustrated by drawings: figure 1 presents a structural diagram of the device; figure 2 - its optoelectronic circuit.

A hydrological device for determining the depth of the jump layer in a natural reservoir contains integrated in a single housing 1 (Fig. 1) depth and density gradient sensors of sea water, made in the form of two fiber coils 2, 3 (Figs. 1, 2), optically matched with a coherent light source 4 and a photodetector 5 (Fig. 2) in an interferometer, which also includes a phase-shifting device in one of the fiber coils, for example, in a coil 2.

The device also contains a weighting sleeve 7. The housing 1 of the device is attached to a cable cable 8, made on the basis of a fiber optic communication line.

On the surface of the studied reservoir there is a surface carrier with a winch, on the drum of which a cable-cable 8 of the device is wound (the carrier with a winch is not shown in the drawing).

The fiber coils 2, 3 of the interferometer are located in figure 1 at a distance Δz, which can vary for different experimental conditions and at the same time set a different degree of averaging of the vertical density gradient in a natural reservoir.

The electronic block diagram of the device includes (Fig. 2) an amplifier-limiter 9, a readout device made in the form of a frequency counter-periodimer 10, a multiplier device 11, and a recorder 12.

The electronic units 9 ... 12 are connected in series, as shown in the drawing. The amplifier-limiter 9 is made with adjustable gain and limitation. This allows us to choose the latter optimal for recording the jump layer.

The multiplying device 11 can be structurally combined with the recorder 12 and the frequency meter-periodimeter 10. The last block has two inputs: a) to start the block and input b) to stop it.

The input a) of the frequency meter-periodimer 10 is connected to the sensor of the start of immersion of the device in a natural reservoir mounted on a winch (the sensor and winch are not shown in the drawing), and input b) is connected to the output of the device (output of limiter amplifier 9).

The phase shifter 6 of the interferometer serves to set the initial phase difference of the interfering rays to 90 °.

The housing 1 of the device is made hollow and communicating with the water of a natural reservoir. Fiber coils 2, 3 with a phase-shifting device 6 are located inside the housing 1, and all electronic units 9-12, a coherent light source 4, and a photodetector 5 are located on an underwater carrier.

Hydrological device operates as follows.

Using a winch (not shown in the drawing), the underwater part of the device is lowered into the investigated natural reservoir.

The beginning of the descent is marked by the command output signal from the winch sensor supplied to the input a) of the frequency-periodimer 10.

The underwater part of the device begins to sink into the reservoir with a uniform speed V.

Since both fiber coils 2, 3 of the interferometer, being in a mixed layer of water, experience the same effect of the medium, the output signal of the interferometer will weakly depend on the depth H of the reservoir and no signal will be present at the output of the amplifier-limiter 9.

But as soon as the device reaches the jump layer located at a depth of H _c , the command output signal supplied to input b) appears at the output of the limiter amplifier 9), to stop counting of the frequency counter-periodimer 10. (Since the jump layer is characterized by a sharp density and temperature gradient water).

In this connection, the frequency-periodometer counts the time t of the uniform lowering of the device with a speed V. The uniformity of the lowering of the device is provided by the winch.

The time t measured in the frequency meter-periodimer 10 in seconds in the multiplier 11 is multiplied by the velocity value V in m / s and the recorder 12 registers the depth of the jump layer H _c = V · t in meters.

Depending on the nature of the water temperature (density) profile in depth, one or another value Δz of the distance between the fiber coils 2, 3 is selected to obtain the steepest front of the output signal of the interferometer at the output of the amplifier-limiter 10. The optimal value of Δz also eliminates false positives instrument for random gradients of their density.

Lifting the device on a surface carrier allows you to specify the location of the jump in a natural reservoir.

Thus, unlike the prototype, the depth of the jump layer in a natural reservoir is determined using one device having an optical output signal, without measuring the absolute value of the temperature and density of water in a natural reservoir.

Sources of information

1. K. Clay, G. Medvin. Acoustic Oceanography. M.: Mir, 1980, pp. 13-21.

2. I.I. Klyukin. Sound and sea. L .: Shipbuilding, 1984, p.22-25.

3. Guide to hydrological work in the oceans and seas. L .: Gidrometeoizdat, 1977, p.130-143 - prototype.

Claims (7)

1. A hydrological device for determining the depth of the jump layer in a natural reservoir, containing the depth and gradient sensors of sea water combined in a single housing, as well as a weighting clutch mounted on a winch cable located on a surface carrier, a reading device for the depth of the reservoir and a recorder that differs the fact that the depth and density gradient sensors of sea water are made in the form of a coherent light source and a photodetector optically matched through two fiber coils in the interferome p, wherein the program further includes a multiplier unit and a limiting amplifier connected to the output of the photodetector input and reading device is designed as a frequency counter-periodimera connected to the input of the output limiter amplifier and output through the multiplier - to the registrar. 2. The hydrological device according to claim 1, characterized in that it further comprises a phase-shifting device installed in one of the fiber coils. 3. The hydrological device according to claim 1, characterized in that a cable-cable made on the basis of a fiber optic communication line is used as a winch cable. 4. The hydrological device according to claim 1, characterized in that the fiber coils of the interferometer are configured to change the distance between them. 5. The hydrological device according to claim 1, or 2, or 3, characterized in that the fiber coils of the interferometer with a phase-shifting device are located in the device’s body, and the coherent light source, a photodetector, an amplifier-limiter, a frequency-periodimer, a multiplying device and a registrar - on underwater media. 6. The hydrological device according to claim 1, characterized in that it further comprises a sensor for starting the immersion of the device connected by the output to the input of the frequency meter-periodimer. 7. The hydrological device according to claim 1 or 6, characterized in that the sensor for starting the immersion of the device is installed on the winch.

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