KR101213362B1 - Ocean Wave Measuring System and Method therefor - Google Patents

Abstract

A ocean wave measuring system and a measuring method thereof are disclosed. An ocean wave measuring system according to an embodiment of the present invention, the pulse source source for periodically supplying light of a wavelength less than the value set in the optical fiber; A coupler interconnecting a plurality of strands of optical fibers and having a sensor for measuring light incident on the optical fiber and light reflected by the optical fiber; And a detector for detecting a signal change according to a change in refractive index among the signals measured by the coupler and displaying the signal as time series data or frequency data, and performing a sensor measurement initialization and an error checking function using a sonar.

Description

Ocean Wave Measuring System and Method therefor

An embodiment of the present invention relates to a marine wave measuring system and a measuring method thereof, and more particularly, to measure changes in ocean waves using optical fibers, and to measure changes in oceans or invasion of enemies based on measured ocean waves. The present invention relates to a marine wave measuring system and a measuring method thereof.

The future battlefield environment is evolving into an unmanned contactless / remote warfare in an environment where manned or unmanned vehicles and ground, air and sea are integrated. In particular, manned or unmanned vehicles perform real-time attacks, indirect fire, air defense, reconnaissance, surveillance, target acquisition, combat command and communication missions, and weapon systems are expected to be more precise, intelligent, and unmanned. It is becoming.

In the underwater environment, manned submersible submarines and ships, unmanned underwater and water robots, and soldiers are expected to maintain the most effective combat system by integrating through networks. In Korea, where three sides are surrounded by the sea, there are many loopholes to be exposed to the limited space of the vast space under the harsh environment and conditions of the sea when invading underwater.

In particular, if enemy forces invade through sea and underwater for the purpose of attacking Jeju Naval Base and Naval Base in Korea, it is possible to properly monitor and cope with the use of satellites, reconnaissance planes and maritime radar. There is an inadequate surveillance system that can completely protect the base, so research and development are urgently needed.

The embodiment of the present invention was devised to meet the needs of the above-mentioned research and development, and measures the change of the ocean wave using the optical fiber, and detects the change of the ocean or the intrusion of the enemy based on the measured change of the ocean wave. An object of the present invention is to provide a marine wave measuring system and a measuring method thereof.

A marine wave measuring system for achieving the above object, the pulse source source for periodically supplying light of a wavelength less than the value set in the optical fiber; A coupler interconnecting a plurality of strands of optical fibers and having a sensor for measuring light incident on the optical fiber and light reflected by the optical fiber; And a detector configured to detect a signal change according to a change in refractive index among the signals measured by the coupler and display the signal as time series data or frequency data.

The optical fiber can be installed on the seabed in a grid shape for marine surveillance.

The apparatus may further include a moving object detecting unit detecting a moving object of the ocean based on a signal measured by the coupler and a signal change detected by the detecting unit.

A sound wave detector (sonar) is provided at the intersection of the optical fiber for the initialization of the measurement and error correction, and the sound wave detector may include at least one of a hydrophone and an acoustic detector.

According to an aspect of the present invention, there is provided a marine wave measuring method, comprising: periodically supplying light having a wavelength equal to or less than a value set in an optical fiber; Measuring light incident to the optical fiber and reflected by the optical fiber; And detecting a signal change according to a change in refractive index among the measured signals and displaying the signal change as time series data or frequency data.

The method may further include detecting a moving body of the ocean based on the measured signal and the detected signal change.

A sound wave detector is provided at the intersection of the optical fiber for the initialization of measurement and error correction, and the sound wave detector may include at least one of a hydrophone and an acoustic detector.

According to an embodiment of the present invention, the change of the ocean wave is measured using the optical fiber, and the movement of the moving body is sensed based on the measured change of the ocean wave to detect the change of the ocean or the intrusion of the enemy.

1 is a view schematically showing a ocean wave measuring system according to an embodiment of the present invention.
2 is a diagram illustrating a reflection coefficient according to a change in refractive index of an optical fiber.
3 is a diagram for explaining a lattice model.
4 is a flowchart illustrating a ocean wave measuring method according to an exemplary embodiment of the present invention.
FIG. 5 is a diagram illustrating ocean wave measurement by the ocean wave measurement system of FIG. 1.
FIG. 6 is a diagram illustrating time series data and frequency data detected by the ocean wave measuring system of FIG. 1.
7 is a diagram for explaining an example of optical fiber installation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known techniques well known to those skilled in the art may be omitted.

In describing the constituent elements of the present invention, the same reference numerals may be given to constituent elements having the same name, and the same reference numerals may be given thereto even though they are different from each other. However, even in such a case, it does not mean that the corresponding component has different functions according to the embodiment, or does not mean that the different components have the same function. It should be judged based on the description of each component in the example.

In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

1 is a view schematically showing a ocean wave measuring system according to an embodiment of the present invention.

Referring to FIG. 1, the ocean wave measuring system 100 according to an exemplary embodiment of the present invention may include a pulse source source 110, a coupler 120, a detector 130, and a moving object detector 140.

The pulse source source 110 periodically supplies light having a wavelength equal to or less than a value set in the optical fiber. Here, the optical fiber is an optical fiber in which total light is reflected through the central glass by using glass having a high refractive index at the center and glass having a low refractive index at the outside. Due to the very low energy loss, the loss rate of the data to be transmitted and received is low and has little influence from the outside. Fibers are made of bundles of fibers that are bundled together to form an optical cable, and its use is growing. The optical fiber is made of synthetic resin, but mainly made of glass with good transparency. The structure of an optical fiber has a double cylinder shape in which a core called a core is wrapped around a portion called cladding. On the outside, one or two coats of synthetic resin are applied to protect it from impact. The total size excluding the protective coating is 100 to hundreds of diameters (1 = 1 / 1000mm), and the refractive index of the core portion is higher than the refractive index of the cladding, so that light can be focused on the core portion and proceed without exiting well. . The diameter of the core is a single mode optical fiber, and the tens are called a multimode optical fiber, and it is divided into a stepped or a hill type optical fiber according to the refractive index distribution of the core. The optical fiber has no interference or interference by external electromagnetic waves, it is difficult to tap, it is small and lightweight, it is strong in bending, it can accommodate many communication lines in one optical fiber, and it is also strong in the change of external environment. Moreover, since the raw material of glass which is a material is very abundant, its utility is high. In the embodiment of the present invention can be configured as an optical cable by tying several strands of the optical fiber as described above, by connecting a plurality of strands of the optical cable in the grid shape horizontally and vertically to the seabed can be used for marine surveillance. . However, the embodiment of the present invention is not limited to an optical cable in which several strands of optical fibers are bundled, and may also be composed of a single strand of optical fiber (hereinafter, the optical fiber is used to include an optical cable). In this case, the size of the grid may be determined according to the object to be monitored. For example, when used to monitor the penetration of enemy ships or submersibles of 50 to 70 m, the grid can be formed to a size of 40 to 60 m, and to measure ocean waves. When used, the size of the grid can be determined according to the size of the ocean wave to be measured. In addition, the position, range and depth of the grid-shaped optical fiber can be determined in consideration of the topographical characteristics of the seabed, the type of the object to be measured. For example, when used to monitor the penetration of enemy warships or submersibles of the size described above, the width of 120-200 m across the infiltration path (for example, between islands). Can be installed as.

The coupler 120 interconnects a plurality of strands of optical fibers, and measures light incident on the optical fiber and light reflected by the optical fiber through a sensor installed in the coupler 120. In this case, the coupler 120 may be installed at the first stage of all optical fibers or may be installed as one using a multiplexer for TDMA (Time Division Multiple Access). And a sonar including at least one of a hydrophone and an acoustic detector at the intersection of the grids. And because sonar is used as a crest meter, it can be used to initialize the sensor, correct error, and improve the accuracy of information compared with the measurement of the fiber optic sensor. The sonar may be installed at each intersection of the lattice shape, or may be selectively installed at any intersection according to the type, size, etc. of the object to be monitored.

Sonar is the name for an acoustic marker used for the detection and expression of underwater objects. Sonar comes from sound navigation and ranging. In a narrow sense, it means hydrophone and sound detector. Corresponds to the Asdic organized by the British Navy during World War I. Hydrophones have been developed since the First World War to detect submarines, especially during and after World War II. Electromagnetic waves and radar waves, such as visible light, are not transmitted to the sea, so they are expressed using ultrasonic waves. The speed of the sound transmitted in the sea varies depending on the situation of the sea, but it is about 1,500 m / s.

There are two types of sonar: the sound sonar, which expresses an object by itself (active sonar), and the hydrophone, which measures the sound from a sound source and expresses it (passive sonar). The former includes an acoustic detector and an acoustic probe, which emits ultrasonic waves as a short intermittent sound and measures the distance to the object by measuring the time it takes to hit the object and return it. It also detects the direction by rotating the transmitter (送 波 器). It is actually the same as radar's PPI scope method, and the distance is measured on the CRT and the bearings are engraved on the circumference so that the scan line rotates with the rotation of the transmitter. Objects appear as light spots to detect distance and orientation. Acoustic side detectors, fish finders, submarine and mine detection sonar, and side looking sonar which detects the structure of the seabed are a kind of sonar in which the main body emits sound waves.

The hydrophones can be found from the time difference of the arrival sound by combining a plurality of directional sounders. When the conditions are good, this type of sonar is capable of detecting ships up to 160 km in length. The sound is different depending on the type and type of ship, and even the type of ship can be distinguished from the sonar type. They are mainly used near the surface of the sea, and there is a variable temperature layer in which the structure of the water temperature is complicated, so that the wave length and the speed of the sound wave change, which limits the effective distance. In general, winter is longer than summer, and tropical and tropical seas are longer. In recent years, in addition to being installed on ships, it is also used for sound wave detector codes for submarine towers dropped from airplanes. Sonar, which is an acoustic detector, uses ultrasonic pulses of about 5,000 to 50,000 Hz every second.

The detector 130 detects a signal change according to a change in refractive index among the signals measured by the coupler 120 and displays the signal as time series data or frequency data. To this end, the detection unit 130 may be connected to an end of the optical fiber to collect light, and may be implemented to analyze the distribution of refractive index changes of all the optical fibers installed in a grid shape. In addition, the detector 130 stores the average value of the refractive index at each position where the coupler 120 is installed, and compares the difference in refractive index of the currently measured signal with respect to the stored average value to detect the change in the refractive index at each position. can do. In this case, the average value of the refractive index may be stored in various steps depending on low water, high water, time, and the like. In addition, the detector 130 may use a Rayleigh scattering algorithm, a Raman scattering algorithm, or the like as an algorithm for analyzing a distribution of refractive index changes. The Rayleigh scattering algorithm is a method of approximating natural frequencies, such as rods and beams. The Rayleigh scattering algorithm assumes an appropriate function representing the normal vibration type, and sets the maximum kinetic energy and maximum potential energy during vibration. It is a method of calculating the natural frequency by the energy method. In addition, the Raman scattering algorithm is one of the spectroscopic methods applying the Raman effect. When the light of monochromatic light is reflected on the material and the wavelength of the scattered light is observed, the scattered light is mixed with light of the material's specific wavelength in addition to the original monochromatic light. This phenomenon is called the Raman effect, which was discovered by Indian physicist C.V. Raman in 1928. In his analysis, he obtained spectra of mercury lamps as light sources, with scattered light of benzene molecules on photo plates, the first Raman spectrum. When a certain frequency of light hits a material, unique energy is absorbed to become scattered light with a small frequency, and it is a phenomenon that occurs due to the emission of unique energy to a scattered light with a large frequency. The higher the symmetry, the higher the degree of polarization. The analysis algorithm of the refractive index used in the embodiment of the present invention is not limited to the presented algorithm. For example, a Block Schur algorithm, a Schur algorithm, or the like may be used.

For example, assuming scattering conditions in an optical fiber, if the internal refractive index of the optical fiber core is changed by pressure or temperature, the light incident on the optical fiber is partially reduced by the reflection coefficient r. Reflected and part transmitted. 2 is a diagram illustrating a reflection coefficient according to a change in refractive index of an optical fiber. Rayleigh scattering of FIG. 2 may be modeled as a lattice model.

3 is a diagram for explaining a lattice model. The lattice model is used for multirate signal processing, inverse scattering, speech signal processing, and the like. The lattic model includes a Finite Impuse Response (FIR) model and an Infinite Impulse Response (IIR) model. FIG. 3 is a diagram illustrating an IIR model. d2, d1, d0 (= 1) are input elements in the z-transform region, n2, n1, n0 are output elements in the z-transform region, and r is the reflection coefficient.

The reflection coefficient r in the lattice model can be obtained through the schur algorithm. The schur algorithm is a fast Cholesky factorization of the toeplitz matrix, which can determine the lattice parameters of the FIR and IIR models.

Assuming an IIR model, a generator matrix G for determining a lattice parameter is represented by Equation 1 below.

To determine the lattice parameter, follow these steps:

The hyperbolic rotation matrix G0 is determined from the first row of the generation matrix G (step 1). In this case, the reflection coefficient r0 from the generation matrix G can be obtained by n0 / 1. The hyperbolic rotation matrix G0 is expressed by Equation 2 below.

The generation matrix G is multiplied by the hyperbolic rotation matrix G0 (step 2). Equation 3 below is a result of multiplying a generation matrix G and a hyperbolic rotation matrix G0.

Shifting down the first column of Equation 3 to obtain the generation matrix G1, and converting the hyperbolic rotation matrix G1 from the second row of the generation matrix G1. Determine (step 3). The hyperbolic rotation matrix G1 from the generation matrix G1 and the second row of the generation matrix G1 is expressed by Equation 4 below.

In this case, the reflection coefficient r1 from the generation matrix G1 can be obtained as shown in Equation 5 below.

Returning to step 2 again, steps 2 and 3 can be repeated to determine the lattice parameter.

Referring back to FIG. 1, the moving object detecting unit 140 detects the ocean wave based on a signal measured by each coupler 120 and a signal change detected by the detecting unit 130 with respect to the plurality of couplers 120. Detect changes or moving bodies in the ocean For example, if the change in the refractive index of the optical fiber in a specific region is more than the set value compared to the average value of the measurement time zone or the difference is more than the set value compared to the average value of the surroundings, It can be detected as. In this case, when the change in the refractive index is sequentially moved according to the position of the sonar, the movement direction of the moving body may be sensed according to the change of the movement. The moving object detecting unit 140 may be used to compare the measured values of the sonar and the measured values of the optical fiber sensor to initialize the sensor, correct the error, and increase the accuracy of the information.

4 is a flowchart illustrating a ocean wave measuring method according to an exemplary embodiment of the present invention. Referring to Figure 4 will be described in more detail the function and operation of the ocean wave measurement system 100 according to an embodiment of the present invention.

As shown in FIG. 5, the pulse source source 110 periodically supplies light having a wavelength equal to or less than a set value to the optical fiber 10 installed on the seabed (S210). In this case, the coupler 120 is connected to the first stage of the optical fiber, and measures the light incident on the optical fiber and the light reflected by the optical fiber (S220). In this case, a sonar including at least one of a hydrophone and an acoustic detector may be used for initializing the sensor measurement and correcting the error in order to increase the accuracy of signal detection.

The detector 130 detects a signal change according to a change in the refractive index among the signals measured by the coupler 120 and displays the signal as time series data or frequency data (S230). When the pressure or temperature applied to the optical fiber 10 changes or the ocean wave contacting the optical fiber 10 changes, the detection unit 130 accordingly changes the time series data or the frequency data as shown in FIG. 6. Will be displayed. In this case, the detection unit 130 may convert time series data into frequency data and display the converted time data, or, conversely, display time series data and frequency data. The reflected light signal can measure the temperature around the optical fiber using Raman Scattering, so it can measure the temperature distribution of the seabed around the optical fiber, and the pressure and temperature using Rayleigh scattering. Various information can be measured by measuring the change, comparing the two measurement information, and extracting only the pressure change component.

As described above, the optical fiber 10 may be installed on the seabed in a lattice shape as shown in FIG. 5. At this time, the spacing of the grid may be installed differently according to the region. In addition, the coupler 120 may be installed at a point where each optical fiber crosses each other.

The moving object detecting unit 140 detects a moving object of the ocean with respect to the plurality of couplers 120 based on the signal measured by each coupler 120 and the signal change detected by the detecting unit 130 (S240). For example, as shown in FIG. 7, when a vessel or a submarine passes through an area in which a grid-shaped optical fiber is installed, a signal change at a corresponding position is detected and displayed by the detector 130, and a change in the displayed time series data is displayed. Alternatively, the movement direction of the ship or submarine can be known according to the change of the frequency data.

Accordingly, the ocean wave measuring system and method according to an embodiment of the present invention measures the change of the ocean wave using the optical fiber, and detects the movement of the moving body based on the measured ocean wave change to detect the change of the ocean or the invasion of the enemy Can be detected.

The present invention is not necessarily limited to these embodiments, as all the constituent elements constituting the embodiment of the present invention are described as being combined or operated in one operation. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. In addition, such a computer program may be stored in a computer-readable medium such as a USB memory, a CD disk, a flash memory, etc., and read and executed by a computer, thereby implementing embodiments of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

Furthermore, all terms including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined in the Detailed Description. Terms used generally, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Further, the scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of the same should be interpreted as being included in the scope of the present invention.

100: ocean wave measurement system
110 pulse source
120: coupler
130: detector
140: moving object detection unit

Claims (8)

A pulse source source that periodically supplies light having a wavelength equal to or less than a value set in the optical fiber;
A coupler interconnecting the plurality of strands of optical fibers, the coupler including a sensor measuring light incident on the optical fiber and light reflected by the optical fiber;
A detector for detecting a signal change according to a change in refractive index among the signals measured by the coupler and displaying the signal as time series data or frequency data; And
And a sonar for initiating measurement and correcting error at the intersection of the optical fibers, wherein the sonar includes at least one of a hydrophone and an acoustic detector. The method of claim 1,
The optical fiber is ocean wave measurement system, characterized in that installed on the seabed in a grid shape for ocean monitoring. The method of claim 1,
Moving object detecting unit for detecting the moving body of the ocean based on the signal measured by each of the coupler and the signal change detected by the detecting unit
Ocean wave measuring system further comprises. delete Periodically supplying light having a wavelength equal to or less than a value set in the optical fiber;
Measuring light incident and connected to the optical fiber and reflected by the optical fiber;
Detecting a signal change according to a change in refractive index among the measured signals and displaying the change in time series data or frequency data; And
And performing initialization and error correction of the measurement by a sound wave detector provided at the intersection of the optical fibers, wherein the sound wave detector comprises at least one of a hydrophone and an sound detector. 6. The method of claim 5,
The optical fiber is a marine wave measuring method, characterized in that installed on the seabed in a grid shape for marine monitoring. 6. The method of claim 5,
Detecting a moving body of the ocean based on the measured signal and the detected signal change
Marine wave measuring method further comprising a. delete

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