CN116559771A - Underwater optical cable space position calibration method based on distributed optical fiber sensing - Google Patents
Underwater optical cable space position calibration method based on distributed optical fiber sensing Download PDFInfo
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/0257—Hybrid positioning
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- G01S5/02585—Hybrid positioning by combining or switching between measurements derived from different systems at least one of the measurements being a non-radio measurement
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Abstract
The invention discloses an underwater optical cable space position calibration method based on distributed optical fiber sensing, which comprises the following steps: driving a calibration ship into a water area to be measured for activity, recording the ship running track by adopting a satellite positioning system, and simultaneously acquiring acoustic wave signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment; obtaining a time-space information distribution diagram containing time domain information; extracting a specific frequency acoustic signal generated by the vessel activity; obtaining a space-time spectrum energy integral graph containing frequency domain information; the method combines the water depth and the calibration ship information, realizes the relation mapping of the energy value and the distance between the ship and the underwater optical cable, corresponds to the ship track at each position along the underwater optical cable, realizes the calibration of the space position of the underwater optical cable, can realize the calibration of the space position of the underwater optical cable, and has the advantages of high efficiency, high positioning precision, low cost and capability of carrying out real-time monitoring analysis.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing, and particularly relates to an underwater optical cable space position calibration method based on distributed optical fiber sensing, which is used for monitoring the underwater optical cable laying state and the ship in the nearby water area.
Background
With the development of the global internet, the requirements of various countries on information transmission efficiency and speed are continuously improved. To meet this demand, submarine fiber optic cables have been spread throughout the world in oceans and water systems. Although the optical cable has the advantages of high bandwidth, high reliability, high durability and the like, due to the problems of ocean current movement, geological activity and the like, the position change of the underwater optical cable is the most main problem in the aspect of monitoring the state of the underwater optical cable. There are three main influencing factors for the change of the position of the underwater optical cable: such as natural factors like geological activity and ocean currents, artificial factors like towing of fishing vessels, and biological factors like marine fish activity. Although the subsea environment is relatively stable, these factors still occur frequently and are difficult to predict, and underwater cable position calibration is difficult and complex.
The method overcomes the difficulty of calibration, requires professional personnel to survey in the field, and has high cost and great difficulty. The current method for calibrating the position of the underwater optical cable mainly comprises two technologies of side-scan sonar and magnetic force measurement. The side-scan sonar is used for detecting acoustic structures and medium properties of the seabed by emitting side-facing sound waves, is suitable for detecting optical cables or pipelines laid on the surface of the seabed, and can select specific frequencies to avoid the influence of other structures or signal sources. However, since the propagation of acoustic waves is limited, it cannot be used to detect an optical cable buried in the sea floor and the trench structure is eroded to be difficult to identify. The magnetic force measurement is a method for detecting by using the magnetic difference of rock mineral substances, and the magnetic difference between the submarine optical cable and the surrounding seabed environment is detected to be a magnetic force abnormal strip, so that the calibration of the optical cable position is realized. The magnetic force measuring technology is not affected by the groove structure, an optical cable buried on the sea floor can be detected, but an error peak value can be generated due to interference of metal objects such as an anchor chain and a fishing gear, meanwhile, the magnetic force measuring instrument used at present is high in cost, and special technologies such as differential positioning and underwater real-time positioning are required to be matched to ensure the measuring accuracy.
In summary, due to randomness of external influence and complexity of underwater environment, the existing underwater optical cable space calibration method has the problems of high cost, complex method, easiness in environmental influence and the like, and a new solution is needed to improve calibration efficiency and accuracy.
Disclosure of Invention
The technical problems to be solved are as follows: the invention discloses a method for calibrating the space position of an underwater optical cable based on distributed optical fiber sensing, which realizes the calibration of the space position of the underwater optical cable through the cooperation of a ship and distributed optical fiber sensing equipment; the method solves the technical problems of high cost, complex method, easy environmental influence and the like of the existing underwater optical cable space calibration method.
The technical scheme is as follows:
an underwater optical cable space position calibration method based on distributed optical fiber sensing comprises the following steps:
s1, accessing distributed optical fiber sensing equipment into an underwater optical cable in a water area to be detected;
s2, driving a calibration ship into a water area to be tested for activity, recording the ship running track by adopting a satellite positioning system, and simultaneously acquiring acoustic signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment;
s3, carrying out phase demodulation on the original signals acquired by the distributed optical fiber sensing equipment, and recovering time domain waveform information at each position along the underwater optical cable to obtain a time-space information distribution diagram containing the time domain information;
s4, performing spectral feature analysis on the time-space information distribution diagram, comparing the time-space information distribution diagram with underwater background noise, extracting a specific frequency sound wave signal generated by ship activity, comparing the specific frequency sound wave signal with a ship running track, and determining whether the specific frequency sound wave signal is related to the ship activity;
s5, carrying out short-time spectrum analysis on signals at each position of the underwater optical cable, carrying out noise suppression on the extracted specific frequency acoustic wave signals generated by ship activities on a frequency domain, and carrying out frequency domain energy integration on the specific frequency to obtain a space-time spectrum energy integration graph containing frequency domain information;
s6, the space-time spectrum energy integrating graph is corresponding to the ship running track, signal energy at each position of the underwater optical cable is used as a weight, and different energy value ranges are mapped into the same range, so that energy value normalization processing is realized;
and S7, combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, carrying out ship track correspondence on all positions along the underwater optical cable, and realizing the calibration of the space position of the underwater optical cable.
In step S2, the calibration ship performs calibration in the underwater optical cable laying water area according to a grid route.
Further, in step S2, for a water area where the underwater optical cable is known to be approximately running, the calibration ship repeatedly passes through the top, so as to form a change of weak strength at each position of the underwater optical cable.
Further, the calibration ship is provided with a transducer, and the transducer continuously outputs a sound wave signal with single frequency and stable sound pressure amplitude as a standard detection signal in the running process of the ship.
Further, the frequency and intensity of the acoustic wave signals continuously output by the transducer are related to the ecological environment of the water area to be measured and the ocean low-frequency background noise.
Further, for the underwater optical cable with the length larger than a preset length threshold, detecting the characteristic frequency of the folded transducer, wherein the characteristic frequency of the folded transducer is larger than a frequency threshold of preset background noise; the specific high-frequency relation between the specific high-frequency of the transducer and the specific frequency after folding is as follows:
f actual ＝f observed +mf k
wherein f actual Characteristic signal frequency, f, actually released for transducer actual For the characteristic signal frequency detected by the distributed optical fiber sensing system, m is an integer not less than 0, f k Is the sampling rate of the system.
Further, in step S4, the specific frequency acoustic wave signal is compared with the ship running track, and acoustic wave signals of the same place and different time are compared to determine whether the specific frequency acoustic wave signal belongs to ocean background noise.
Further, in step S7, in combination with the water depth and the calibration ship information, the mapping of the relationship between the energy value and the distance between the ship and the underwater optical cable is realized, the ship track correspondence is performed on each position along the underwater optical cable, and the process of realizing the calibration of the space position of the underwater optical cable includes the following steps:
the track data is corresponding to the space-time spectrum energy integral graph, and the inflection points of the ship track are mapped on a distance axis and a time axis; positioning the position of the maximum energy value, wherein the maximum energy value is obtained when the calibration ship passes right above the underwater optical cable;
acquiring the track and time information of a calibrated ship, and combining the water depth and the energy maximum position information to realize the relation mapping of the energy value and the distance between the ship and the underwater optical cable;
and according to the energy distance mapping relation, carrying out ship track correspondence on all positions along the underwater optical cable, and calculating the corresponding distance.
The invention also discloses a ship position calibration method based on distributed optical fiber sensing, which comprises the following steps:
accessing the distributed optical fiber sensing equipment with known space positions of the underwater optical cable into the underwater optical cable in the water area to be measured;
driving a ship to be tested into a water area to be tested for activity, and acquiring acoustic wave signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment;
carrying out phase demodulation on an original signal acquired by distributed optical fiber sensing equipment, and recovering time domain waveform information at each position along an underwater optical cable to obtain a time-space information distribution diagram containing the time domain information;
performing spectral feature analysis on the time-space information distribution map, comparing the time-space information distribution map with underwater background noise, and extracting a specific frequency sound wave signal generated by ship activity;
carrying out short-time spectrum analysis on signals at each position of an underwater optical cable, carrying out noise suppression on the extracted specific frequency acoustic wave signals generated by ship activities on a frequency domain, and carrying out frequency domain energy integration on the specific frequency to obtain a space-time spectrum energy integration graph containing frequency domain information;
the space-time spectrum energy integrating graph is corresponding to the space position of the underwater optical cable, signal energy at each position of the underwater optical cable is used as a weight, and different energy value ranges are mapped into the same range, so that energy value normalization processing is realized;
and combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, and carrying out ship track correspondence according to the space position of the underwater optical cable, thereby realizing the calibration of the ship position.
The beneficial effects are that:
firstly, the method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing has the advantages that the distributed optical fiber sensing equipment is used as a monitoring device, the underwater optical cable is used as a sensing main body, the calibration ship is used as an excitation source, the space position calibration of the underwater optical cable can be realized, the efficiency is high, the positioning precision is high, the cost is low, and the real-time monitoring analysis can be performed.
Secondly, the ship position calibration method based on distributed optical fiber sensing can realize the monitoring of hydrologic conditions near the underwater optical cable and the rapid identification and positioning of the water ship by combining the distributed optical fiber sensing equipment for the underwater optical cable with the position calibration.
Drawings
FIG. 1 is a schematic diagram of a monitoring scenario according to an embodiment of the present invention;
FIG. 2 is a drawing of a calibrated watercraft travel path in accordance with an embodiment of the present invention;
FIG. 3 is a flowchart of a method for calibrating the spatial position of an underwater optical cable based on distributed optical fiber sensing according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of the spatial and temporal information distribution obtained by an underwater optical cable according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a short-time spectrum of an embodiment of the present invention at a position of 100m of an submarine cable;
FIG. 6 is a schematic diagram of the spatial and temporal information distribution of an underwater optical cable at a specific frequency according to an embodiment of the present invention;
FIG. 7 is a plot of the energy integration of the space-time spectrum of an underwater optical cable in accordance with an embodiment of the present invention;
FIG. 8 is a schematic diagram of the result of calibrating the spatial position of an underwater optical cable according to an embodiment of the present invention.
Detailed Description
The following examples will provide those skilled in the art with a more complete understanding of the invention, but are not intended to limit the invention in any way.
The embodiment discloses an underwater optical cable space position calibration method based on distributed optical fiber sensing, which comprises the following steps:
s1, accessing distributed optical fiber sensing equipment into an underwater optical cable in a water area to be detected;
s2, driving a calibration ship into a water area to be tested for activity, recording the ship running track by adopting a satellite positioning system, and simultaneously acquiring acoustic signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment;
s3, carrying out phase demodulation on the original signals acquired by the distributed optical fiber sensing equipment, and recovering time domain waveform information at each position along the underwater optical cable to obtain a time-space information distribution diagram containing the time domain information;
s4, performing spectral feature analysis on the time-space information distribution diagram, comparing the time-space information distribution diagram with underwater background noise, extracting a specific frequency sound wave signal generated by ship activity, comparing the specific frequency sound wave signal with a ship running track, and determining whether the specific frequency sound wave signal is related to the ship activity;
s5, carrying out short-time spectrum analysis on signals at each position of the underwater optical cable, carrying out noise suppression on the extracted specific frequency acoustic wave signals generated by ship activities on a frequency domain, and carrying out frequency domain energy integration on the specific frequency to obtain a space-time spectrum energy integration graph containing frequency domain information;
s6, the space-time spectrum energy integrating graph is corresponding to the ship running track, signal energy at each position of the underwater optical cable is used as a weight, and different energy value ranges are mapped into the same range, so that energy value normalization processing is realized;
and S7, combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, carrying out ship track correspondence on all positions along the underwater optical cable, and realizing the calibration of the space position of the underwater optical cable.
The principle of the underwater optical cable spatial position calibration method based on distributed optical fiber sensing of the present embodiment is explained below by way of an example. It should be understood that the data such as the underwater cable or the ship acoustic signal in this example is not limited as long as the basic requirements of the method described in this embodiment are met.
The monitoring scene and the monitoring scheme of the embodiment are shown in fig. 1, the distributed sensing equipment is a DAS system, the DAS system is installed in a shore-end machine room, the length of an underwater optical cable is 1km, a calibration ship moves in an underwater optical cable laying water area, a calibration movement track is shown in a solid line in fig. 2, a flow of an underwater optical cable space position calibration method is shown in fig. 3, and the specific process is as follows:
step one, a DAS system is connected into a water area to be detected to obtain an underwater optical cable, the pulse repetition frequency of the system is set to be 5km, the monitoring distance is 1km, and the spatial resolution is 10m; and acquiring acoustic signals at various positions along the underwater optical cable.
And step two, driving a calibration ship capable of acquiring the self-positioning coordinates in real time into a water area to be tested to perform activities, mainly moving in the water area near the underwater optical cable, and acquiring and recording the ship running track by using a satellite positioning system. The calibration ship can calibrate in the water area where the underwater optical cable is laid in a grid-shaped route, and for the water area where the known underwater optical cable is approximately arranged, the calibration ship should repeatedly pass through the top as much as possible, and the change of the strength of the weakness is formed at each position of the underwater optical cable to be optimal.
The calibration ship can preferably be a ship capable of carrying the transducer, and continuously outputs a signal with single frequency and stable sound pressure amplitude as a standard detection signal through the transducer carried by the calibration ship, so that the signal characteristics are obvious and the calibration ship is easy to distinguish from background noise. For example, the calibration vessel carries a transducer that releases a single tone signal of constant intensity at a frequency of 1 khz. The characteristic frequency released by the transducer avoids overlapping with the marine low-frequency background noise as much as possible, and proper sound wave frequency and intensity are selected according to specific conditions and ecological environments, so that the influence on underwater organisms is avoided.
For the underwater optical cable which needs to be monitored for a long distance, the frequency band which can be observed is limited, high-frequency folding possibly occurs when the characteristic frequency of the transducer is too high, specific high frequency can be selected, the folded characteristic frequency is detected, the folded characteristic frequency is larger than the frequency threshold value of preset background noise, and the relation between the specific high frequency of the transducer and the folded specific frequency is calculated as follows:
f actual ＝f observed +mf k
wherein f actual Characteristic signal frequency, f, actually released for transducer actual For the characteristic signal frequency detected by the distributed optical fiber sensing system, m is an integer not less than 0, f k Is the sampling rate of the system.
The system monitors in long distance, the upper limit of the frequency that the system can observe is reduced, and if the system monitors in short distance, the upper limit of the frequency that the system can observe is increased. If the applied vibration frequency exceeds the observable frequency, the folded frequency value can be monitored through the formula, so that the high frequency is monitored. The purpose of applying high frequency is mainly to avoid low-frequency ocean background noise, so that confusion is avoided, and meanwhile, the folded specific frequency should avoid the low-frequency background noise, so that confusion is prevented, and the low-frequency ocean background noise is not easy to distinguish.
And thirdly, carrying out phase demodulation on the original signals acquired by the DAS system, and recovering time domain waveform information at each position along the underwater optical cable to obtain a time-space information distribution diagram containing the time domain information, as shown in fig. 4.
Step four, performing spectral feature analysis on the time-space information distribution map, comparing the time-space information distribution map with underwater background noise, and comparing and analyzing signals at the position of 100m to obtain a graph 5, wherein as can be seen from the graph 5, 1khz signals generated when a calibrated ship passes are detected by a DAS system, so that only frequencies around 1khz are selected to be reserved, bandpass filtering is performed, and non-calibrated ship signals are filtered, so that the time-space information distribution map of the underwater optical cable under specific frequencies is obtained as shown in the graph 6. And further compares to the ship's travel path to determine that the sonic signal at that frequency is related to ship activity, but that the signal characteristics are not apparent. Illustratively, the characteristic frequency identification process is as follows: because the real-time position and trajectory of the calibration vessel is known, the time domain signal captured near the underwater fiber optic cable will change as the calibration vessel passes before and after the underwater fiber optic cable. Therefore, the acquired sound wave signals can be subjected to spectrum analysis, sound wave signals with specific frequencies can be found out, the sound wave signals are further compared with the calibrated ship running track, and the sound wave signals with the frequencies are determined to be related to ship activities. Meanwhile, the sound wave signals of the same place and different time are compared, and whether the sound wave signals belong to ocean background noise is judged. To prevent erroneous judgment.
Step six, carrying out short-time spectrum analysis on signals at each position of each underwater optical cable, setting the observation time length to be 1s, carrying out spectrum subtraction on signals near the 1000Hz characteristic frequency on a frequency domain, then selecting a frequency band range with the frequency of 1000Hz and the bandwidth of 10Hz to carry out frequency domain energy integration, and obtaining a space-time spectrum energy integration graph containing frequency domain information, as shown in figure 7; the darker the color can be considered, the closer the calibration vessel is to the cable, the corresponding vessel movement time to the data, and the response characteristics of the vessel along the cable at each critical location can be obtained.
And step seven, the track data is corresponding to the space-time spectrum energy integral graph, and the maximum energy value of the ship at the point G is found, namely the ship just passes through the position above the underwater optical cable. And mapping inflection points of the ship track on a distance axis and a time axis, calculating energy values of all position points along the underwater optical cable, mapping different energy value ranges into the same range, and realizing energy value normalization processing.
And step eight, combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, and carrying out ship track correspondence on all positions along the underwater optical cable according to the energy distance mapping relation to obtain the actual trend of the underwater optical cable in FIG. 8, thereby realizing the calibration of the space position of the underwater optical cable. Illustratively, the submarine cable spatial location calibration process is as follows:
(1) The trajectory data is corresponding to a space-time spectrum energy integral graph, and ship trajectory inflection points are mapped on a distance axis and a time axis:
(2) And calculating the energy value of each position point along the underwater optical cable, and mapping different energy value ranges into the same range to realize energy value normalization processing. The larger the energy value is, the closer the calibration vessel is to the underwater optical cable, and the smaller the energy value is, the farther the calibration vessel is from the underwater optical cable;
(3) When the calibration ship passes right above the underwater optical cable, the energy value is maximum, and the position of the maximum energy value is positioned;
(4) Acquiring the track and time information of a calibrated ship, and combining the water depth and the energy maximum position information to realize the relation mapping of the energy value and the distance between the ship and the underwater optical cable;
(5) And according to the energy distance mapping relation, carrying out ship track correspondence on all positions along the underwater optical cable, and calculating the corresponding distance.
According to the method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing, disclosed by the embodiment, the distributed optical fiber sensing equipment is used as a monitoring device, the underwater optical cable is used as a sensing main body, and the calibration ship is used as an excitation source, so that the space position calibration of the underwater optical cable can be realized, and the method has the advantages of high efficiency, high positioning precision and low cost, and can be used for real-time monitoring and analysis. In addition, the method is not only suitable for calibrating the position of the underwater optical cable, but also can realize the monitoring of the hydrologic condition near the underwater optical cable by combining the distributed optical fiber sensing equipment for the underwater optical cable with the position calibration of the underwater optical cable, and can also realize the rapid identification and positioning of the water ship, thereby providing a quicker and more accurate judgment method for the space position calibration of the underwater optical cable.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (9)
1. The method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing is characterized by comprising the following steps of:
s1, accessing distributed optical fiber sensing equipment into an underwater optical cable in a water area to be detected;
s2, driving a calibration ship into a water area to be tested for activity, recording the ship running track by adopting a satellite positioning system, and simultaneously acquiring acoustic signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment;
s3, carrying out phase demodulation on the original signals acquired by the distributed optical fiber sensing equipment, and recovering time domain waveform information at each position along the underwater optical cable to obtain a time-space information distribution diagram containing the time domain information;
s4, performing spectral feature analysis on the time-space information distribution map, comparing the time-space information distribution map with underwater background noise, and extracting a specific frequency sound wave signal generated by ship activity;
s5, carrying out short-time spectrum analysis on signals at each position of the underwater optical cable, carrying out noise suppression on the extracted specific frequency acoustic wave signals generated by ship activities on a frequency domain, and carrying out frequency domain energy integration on the specific frequency to obtain a space-time spectrum energy integration graph containing frequency domain information;
s6, the space-time spectrum energy integrating graph is corresponding to the ship running track, signal energy at each position of the underwater optical cable is used as a weight, and different energy value ranges are mapped into the same range, so that energy value normalization processing is realized; the larger the energy value is, the closer the calibration vessel is to the underwater optical cable, and the smaller the energy value is, the farther the calibration vessel is from the underwater optical cable;
and S7, combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, carrying out ship track correspondence on all positions along the underwater optical cable, and realizing the calibration of the space position of the underwater optical cable.
2. The method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing according to claim 1, wherein in the step S2, the calibration ship performs calibration in a grid-shaped route in an underwater optical cable laying water area.
3. The method for calibrating the spatial position of the underwater optical cable based on the distributed optical fiber sensing according to claim 2, wherein in the step S2, the calibration ship repeatedly passes through the top of the water area where the underwater optical cable is known to be approximately running, so as to form the change of the strength of the weakness at each position of the underwater optical cable.
4. The method for calibrating the spatial position of an underwater optical cable based on distributed optical fiber sensing according to claim 1, wherein the calibration vessel carries a transducer which continuously outputs an acoustic wave signal with single frequency and stable sound pressure amplitude as a standard detection signal during the running process of the vessel.
5. The method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing according to claim 4, wherein the frequency and the intensity of the acoustic wave signals continuously output by the transducer are related to the ecological environment of the water area to be tested and the ocean low-frequency background noise.
6. The method for calibrating the spatial position of the underwater optical cable based on the distributed optical fiber sensing according to claim 1, wherein for the underwater optical cable with the length larger than a preset length threshold, the characteristic frequency of the folded transducer is detected, and the characteristic frequency after the folding is larger than a frequency threshold of preset background noise; the specific high-frequency relation between the specific high-frequency of the transducer and the specific frequency after folding is as follows:
f actual ＝f observed +mf k
wherein f actual Characteristic signal frequency, f, actually released for transducer actual For the characteristic signal frequency detected by the distributed optical fiber sensing system, m is an integer not less than 0, f k Is the sampling rate of the system.
7. The method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing according to claim 1, wherein in the step S4, the specific frequency acoustic wave signal is compared with the ship running track, and the acoustic wave signals of the same place and different time are compared to judge whether the specific frequency acoustic wave signal belongs to ocean background noise.
8. The method for calibrating the space position of the underwater optical cable based on the distributed optical fiber sensing according to claim 1, wherein in the step S7, the relation mapping between the energy value and the distance between the ship and the underwater optical cable is realized by combining the water depth and the calibration ship information, the ship track correspondence is carried out on the underwater optical cable at each position along the line, and the process for calibrating the space position of the underwater optical cable is realized by the following steps:
the track data is corresponding to the space-time spectrum energy integral graph, and the inflection points of the ship track are mapped on a distance axis and a time axis; positioning the position of the maximum energy value, wherein the maximum energy value is obtained when the calibration ship passes right above the underwater optical cable;
acquiring the track and time information of a calibrated ship, and combining the water depth and the energy maximum position information to realize the relation mapping of the energy value and the distance between the ship and the underwater optical cable;
and according to the energy distance mapping relation, carrying out ship track correspondence on all positions along the underwater optical cable, and calculating the corresponding distance.
9. The ship position calibration method based on distributed optical fiber sensing is characterized by comprising the following steps of:
accessing the distributed optical fiber sensing equipment with known space positions of the underwater optical cable into the underwater optical cable in the water area to be measured;
driving a ship to be tested into a water area to be tested for activity, and acquiring acoustic wave signals at all positions along the underwater optical cable by adopting distributed optical fiber sensing equipment;
carrying out phase demodulation on an original signal acquired by distributed optical fiber sensing equipment, and recovering time domain waveform information at each position along an underwater optical cable to obtain a time-space information distribution diagram containing the time domain information;
performing spectral feature analysis on the time-space information distribution map, comparing the time-space information distribution map with underwater background noise, and extracting a specific frequency sound wave signal generated by ship activity;
carrying out short-time spectrum analysis on signals at each position of an underwater optical cable, carrying out noise suppression on the extracted specific frequency acoustic wave signals generated by ship activities on a frequency domain, and carrying out frequency domain energy integration on the specific frequency to obtain a space-time spectrum energy integration graph containing frequency domain information;
the space-time spectrum energy integrating graph is corresponding to the space position of the underwater optical cable, signal energy at each position of the underwater optical cable is used as a weight, and different energy value ranges are mapped into the same range, so that energy value normalization processing is realized;
and combining the water depth and the calibration ship information, realizing the relation mapping of the energy value and the distance between the ship and the underwater optical cable, and carrying out ship track correspondence according to the space position of the underwater optical cable, thereby realizing the calibration of the ship position.
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| CN117491947A (en) * | 2023-12-29 | 2024-02-02 | 高勘(广州)技术有限公司 | Object track tracking method, device, equipment and storage medium |
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| CN117491947A (en) * | 2023-12-29 | 2024-02-02 | 高勘(广州)技术有限公司 | Object track tracking method, device, equipment and storage medium |
| CN117491947B (en) * | 2023-12-29 | 2024-04-12 | 高勘(广州)技术有限公司 | Object track tracking method, device, equipment and storage medium |
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