阅读说明：本技术 海底四分量节点地震数据采集系统及其数据采集方法 (Seabed four-component node seismic data acquisition system and data acquisition method thereof ) 是由 苟量 余刚 刘海波 徐朝红 王熙明 夏淑君 安树杰 肖梦雄 于 2021-09-30 设计创作，主要内容包括：本发明涉及一种海底四分量节点地震数据采集系统及其数据采集方法,包括沉放到海底的水声发射源潜标,海面带有GPS或北斗信号接收天线的浮标通过内置连续光栅光纤的光电复合缆与海底水声发射源潜标相连,海底四分量节点地震仪器顶部安装有水声应答器。海面浮标将定位和授时信号通过光电复合缆传送到海底的潜标内,布放到海底的四分量节点地震仪器通过工区四周布放的海底水声发射源潜标发出的水声信号进行精确定位与授时。海面浮标内置的复合调制解调仪器和连续光栅光纤缆实时测量从海面到海底的海水温度、压力、密度、含盐饱和度等参数,用于对海底潜标发射的水声信号速度进行修正,确保海底节点地震仪器的定位和授时精度满足误差要求。(The invention relates to a seabed four-component node seismic data acquisition system and a data acquisition method thereof, which comprise an underwater sound emission source subsurface buoy sunk to the seabed, wherein a buoy with a GPS or Beidou signal receiving antenna on the sea surface is connected with the seabed underwater sound emission source subsurface buoy through a photoelectric composite cable with a built-in continuous grating optical fiber, and the top of a seabed four-component node seismic instrument is provided with an underwater sound transponder. The sea surface buoy transmits positioning and time service signals to the submarine submerged buoy through the photoelectric composite cable, and the four-component node seismic instrument arranged on the seabed carries out accurate positioning and time service through underwater acoustic signals sent by the submarine underwater acoustic emission source submerged buoy arranged around the work area. A composite modulation and demodulation instrument and a continuous grating optical fiber cable which are arranged in the sea surface buoy measure parameters such as sea water temperature, pressure, density, salt saturation and the like from the sea surface to the sea bottom in real time, and are used for correcting the speed of underwater acoustic signals transmitted by the submarine submerged buoy to ensure that the positioning and time service precision of the submarine node seismic instrument meets the error requirement.)

1. The seabed four-component node seismic data acquisition system is characterized by comprising a plurality of seabed submerged buoys (1), a plurality of sea surface buoys (4), an armored photoelectric composite cable (10), a plurality of seabed four-component node seismic data acquisition instruments (11) and a sea surface seismic source ship (13);

a plurality of the seabed four-component node seismic data acquisition instruments (11) are arranged in a seabed seismic data acquisition work area according to a pre-designed measurement grid;

the plurality of submarine submerged beacons (1) are arranged around a submarine seismic data acquisition work area, and the submarine submerged beacons (1) correspond to sea surface buoys (4) one by one and are connected through armored photoelectric composite cables (10);

and the sea surface seismic source ship (13) carries out seismic source excitation below the water surface of the submarine seismic data acquisition work area through an air gun seismic source (14) towed by the stern.

2. The seabed four-component node seismic data acquisition system as claimed in claim 1, wherein the seabed submerged buoy (1) is internally provided with a long baseline or short baseline or ultra-short baseline positioning system underwater acoustic signal emission source (2) and a rechargeable battery (3);

the sea surface buoy (4) is internally provided with a GPS and Beidou satellite signal receiving antenna (5), a solar cell panel (6), a photoelectric conversion module (7) and a composite modulation and demodulation instrument (8).

3. The seabed four-component node seismic data acquisition system according to claim 1, wherein a cable (9) is arranged in the armored photoelectric composite cable (10), and the outer layer of the armored photoelectric composite cable is wrapped with a high-strength sheath woven by Kevlar fibers or armored by twisting one or more layers of stainless steel wires; the cable (9) comprises a continuous grating optical fiber, a single mode and multimode optical fiber, a coaxial cable and a twisted pair power supply line.

4. The seabed four-component node seismic data acquisition system according to claim 1, wherein a hydroacoustic transponder (12) is installed on the top of the seabed four-component node seismic data acquisition instrument (11), and the four-component node seismic data acquisition instrument (11) is a conventional four-component node seismic data acquisition instrument with a built-in three-component conventional geophone and a piezoelectric hydrophone, or an optical fiber four-component node seismic data acquisition instrument.

5. The submarine four-component-node seismic instrument based on underwater acoustic signal positioning time service according to claim 4, wherein the submarine optical fiber four-component seismic data acquisition instrument (11) comprises a pressure-bearing cabin, and a three-component optical fiber geophone, an optical fiber sound pressure hydrophone, a three-component attitude sensor, a semiconductor light source, an internal photoelectric conversion module, a modulation and demodulation module, a pre-amplification and A/D conversion module, a data storage module and a rechargeable battery module are arranged in the pressure-bearing cabin.

6. The data acquisition method of the seafloor four-component node seismic data acquisition system as claimed in any one of claims 1 to 5, comprising the steps of:

(a) firstly, four submarine submerged beacons (1) are put around a submarine seismic data acquisition work area, the tail end of an armored photoelectric composite cable (10) is connected with the submarine submerged beacons (1), and the head end of the armored photoelectric composite cable is connected with a sea surface buoy (4);

(b) laying the seabed four-component node seismic data acquisition instrument (11) to the seabed of the seabed seismic data acquisition work area by using a rope, a steel cable or an ROV according to a pre-designed network measurement coordinate;

(c) starting instruments in the submarine submerged buoy (1) and the sea surface buoy (4), and sending positioning and time service signals received by a GPS (global positioning system) or Beidou satellite signal receiving antenna (5) in the sea surface buoy (4) to the submarine submerged buoy (1) through a photoelectric composite cable;

(d) the submarine subsurface buoy (1) transmits positioning and time service signals to a water area around a submarine four-component node seismic data acquisition instrument (11) through an underwater acoustic signal emission source (2);

(e) the underwater acoustic transponder (12) arranged at the top of each seabed four-component node seismic data acquisition instrument (11) respectively receives positioning and time service signals transmitted from the seabed submerged buoy (1) and carries out accurate positioning and uninterrupted real-time service on the underwater acoustic transponder;

(f) various optical fibers in the armored photoelectric composite cable (10) are connected with a composite modulation and demodulation instrument (8) in the sea surface buoy (4), and the water temperature, the pressure, the density and the salt saturation of seawater at the position from the sea surface to the seabed submerged buoy (1) along the armored photoelectric composite cable (10) are measured in real time and uninterruptedly;

(g) the real-time three-dimensional water temperature, pressure, density and salt saturation value of seawater in the water body of the total measurement region are calculated by interpolation by utilizing the water temperature, pressure and density from the sea surface to the position of the submarine submerged buoy (1) measured by all the armored photoelectric composite cables (10);

(h) according to the accurately positioned position of each seabed four-component node seismic data acquisition instrument (11) and the underwater sound transmission track connecting line between each seabed submerged buoy, calculating the real-time three-dimensional water temperature, pressure, density and salt saturation numerical value of seawater in the water body of the seabed seismic data acquisition region by using the step (g), and performing real-time correction on the underwater sound speed on each underwater sound transmission track from the seabed submerged buoy (1) to each seabed four-component node seismic data acquisition instrument (11);

(i) and (3) correcting the positioning and time service data of each seabed four-component node seismic data acquisition instrument (11) in real time by using the real-time correction value of the underwater sound velocity of each underwater sound propagation track from the seabed submerged buoy (1) to each seabed four-component node seismic data acquisition instrument (11), and ensuring that the positioning and time service precision of each seabed four-component node seismic data acquisition instrument (11) meets the measurement error requirement in the measurement work area.

Technical Field

The invention belongs to the technical field of marine geophysical exploration, and relates to a seabed four-component node seismic data acquisition system and a data acquisition method thereof.

Background

Marine seismic exploration is a method of conducting seismic exploration at sea using an exploration vessel. The principles of marine seismic exploration, the instruments used, and the methods of processing data are essentially the same as those for land seismic exploration. The submarine seismic exploration technology is one of marine seismic exploration technologies and also comprises a seismic source and an acquisition instrument. The ocean bottom seismic exploration technology mostly adopts a non-explosive seismic source (mainly an air gun), the seismic source floats on the sea surface and is towed by an offshore seismic exploration ship; the acquisition instrument is placed on the seabed to receive longitudinal and transverse wave signals which are emitted by the seismic source and reflected by the bottom layer of the seabed. Because the sea water can not transmit the transverse wave, the transverse wave and the converted wave can be received only by placing the detector on the sea bottom. The method is characterized in that the method comprises the steps of excitation in water, receiving in water, excitation and receiving conditions are uniform; continuous observation without stopping the ship can be performed. Geophones originally used piezoelectric geophones and now developed to use piezoelectric in combination with velocity geophones. The Ocean Bottom seismic exploration technology can be divided into Ocean Bottom Cable exploration technology (OBC for short) and Ocean Bottom Node seismic exploration technology (OBN for short). The OBC technology is that hundreds of detectors are connected to a submarine cable, a special line-laying boat sinks a collection cable to the seabed (the submarine cable can be one or more) under the guidance of a positioning instrument, one end of the submarine cable is connected to a fixed instrument ship (the instrument ship needs to be anchored at the sea front and back to ensure that a ship body does not turn and a ship position does not shift), and a marine seismic exploration ship collects submarine seismic data around the sea surface in a designed line-laying blasting mode.

The current ocean bottom seismic data acquisition modes mainly comprise two modes, wherein one mode is that a single-component, two-component, three-component or four-component ocean bottom seismic data acquisition cable (OBC) sinks into the ocean bottom to acquire seismic data, the other mode is that an independent three-component or four-component ocean bottom seismic data acquisition station (OBS and OBN) sinks to acquire seismic data, and the two modes are both excited by using an independent ocean seismic air gun excitation source when the ocean seismic air gun excitation source is dragged in water. Independent ocean bottom seismic data acquisition cables and ocean bottom seismic data acquisition stations such as various OBC, OBS and OBN manufactured and sold by the companies ION, Sercel, Fairfield and OYOGeospace, etc.

The ocean bottom node seismic detector exploration technology (OBN) is that node seismic detectors are placed under water without cable for power supply and do not communicate, each node seismic detector operates autonomously and is completely independent of all other nodes, and data can be continuously acquired for several months. The data acquisition job for the OBN is two-vessel operation-a source vessel and a nodal seismic instrumentation deployment and recovery vessel. The arrangement mode and the distance of the node seismic instruments are not restricted, and the node seismic instruments are suitable for omnidirectional exploration. When the node seismic instruments are arranged, each node seismic instrument may be additionally provided with a rope line or a steel wire cable, so that the node seismic instruments can be easily recovered, and the method is similar to a fisherman in recovering long serial crab cages. When the node seismic instruments are arranged on the seabed of thousands of meters of water depth, no additional line or steel cable is suitable, the ROV generally carries the node seismic instruments, the instruments are arranged on the seabed according to designed measuring point coordinates, and when the instruments are recovered, the ROV also submerges to the seabed to recover the deep-water node seismic instruments one by one.

Because the power supply and communication cable is not connected with the submarine node seismic instrument, the submarine node seismic instrument cannot be powered in real time or charged by batteries, so that the submarine node seismic instrument needs to carry a large number of rechargeable batteries to ensure that the submarine node seismic instrument can work on the seabed for a long time, the production cost, the volume and the weight of the node seismic instrument are increased, the node seismic instrument thrown on the seabed cannot be positioned, the working state of the submarine node seismic instrument cannot be monitored in real time, data collected by the submarine node seismic instrument cannot be transmitted in real time (the submarine node seismic instrument can only carry out blind acquisition), and the node seismic instrument working on the seabed cannot be timed, and the node seismic instrument can only rely on an expensive atomic clock chip to give time to the instrument, and time service errors can be caused by time drift of the atomic clock chip during submarine work for a long time.

The optical fiber geophone has the advantages of high sensitivity, wide frequency band, good high-frequency response, flat frequency characteristic response, linear phase change, good technical parameter consistency, stable and reliable performance, no electricity or passive, corrosion resistance and high temperature resistance, and is the development direction of the geophone technology. Compared with the conventional detector, the optical fiber detector has higher sensitivity and better high-frequency response characteristic, and can realize multi-channel, large-data-volume and high-speed transmission. And because the front end does not have electronic components, the high-voltage-resistant cable has higher reliability, high temperature and high voltage resistance, does not need power supply, is waterproof and corrosion-resistant, can be laid for a long time, resists electromagnetic interference and has small channel crosstalk.

Disclosure of Invention

In view of the technical problems that the existing ocean bottom node seismic instrument cannot be accurately positioned, an atomic clock is expensive and has time service drift, the invention provides an ocean bottom four-component node seismic data acquisition system and a data acquisition method thereof, which overcome the defects that the existing technology cannot accurately position and accurately time service the ocean bottom node seismic instrument in real time during operation, and replace an atomic clock chip which is expensive and cannot avoid time service drift.

The bottom four-component node seismic data acquisition system comprises a plurality of submarine submerged buoys, a plurality of sea surface buoys, armored photoelectric composite cables, a plurality of submarine four-component node seismic data acquisition instruments and a sea surface seismic source ship;

a plurality of seabed four-component node seismic data acquisition instruments are distributed in a seabed seismic data acquisition work area;

the submarine submerged buoy is arranged around a submarine seismic data acquisition work area, corresponds to the sea surface buoy one by one and is connected through an armored photoelectric composite cable;

and the sea surface seismic source ship carries out seismic source excitation below the water surface of the submarine seismic data acquisition work area through an air gun seismic source (14) towed by the stern.

Wherein, the submarine submerged buoy is internally provided with an underwater sound signal emission source of a long baseline or short baseline or ultra-short baseline positioning system and a rechargeable battery;

the sea surface buoy is internally provided with a GPS and Beidou satellite signal receiving antenna, a solar cell panel, a photoelectric conversion module and a composite modulation and demodulation instrument.

The armored photoelectric composite cable is internally provided with a cable, and the outer layer of the armored photoelectric composite cable is wrapped with a high-strength sheath woven by Kevlar fibers or armored by twisting one or more layers of stainless steel wires; the cable comprises a continuous grating optical fiber, a single mode optical fiber, a multimode optical fiber, a coaxial cable and a twisted pair power supply line.

The top of the seabed four-component node seismic data acquisition instrument is provided with a hydroacoustic transponder, and the four-component node seismic data acquisition instrument is a conventional four-component node seismic data acquisition instrument internally provided with a three-component conventional geophone and a piezoelectric hydrophone or an optical fiber four-component node seismic data acquisition instrument.

The submarine optical fiber four-component seismic data acquisition instrument comprises a pressure bearing cabin, wherein a three-component optical fiber detector, an optical fiber sound pressure hydrophone, a three-component attitude sensor, a semiconductor light source, an internal photoelectric conversion module, a modulation and demodulation module, a preposed amplification and A/D conversion module, a data storage module and a rechargeable battery module are arranged in the pressure bearing cabin.

The data acquisition method of the seabed four-component node seismic data acquisition system comprises the following steps:

(a) firstly, four submarine submerged beacons are put around a submarine seismic data acquisition work area, the tail end of an armored photoelectric composite cable is connected with the submarine submerged beacons, and the head end of the armored photoelectric composite cable is connected with a sea surface buoy;

(b) the method comprises the following steps of putting a seabed four-component node seismic data acquisition instrument to the seabed of a seabed seismic data acquisition work area by using a rope, a steel cable or an ROV according to a pre-designed network measurement coordinate;

(c) starting instruments in the submarine submerged buoy and the sea surface buoy, and sending positioning and time service signals received by a GPS or Beidou satellite signal receiving antenna in the sea surface buoy to the submarine submerged buoy through a photoelectric composite cable;

(d) the submarine submerged buoy transmits positioning and time service signals to a water area around a submarine four-component node seismic data acquisition instrument through an underwater acoustic signal emission source;

(e) the underwater acoustic transponder installed at the top of each seabed four-component node seismic data acquisition instrument respectively receives positioning and time service signals transmitted by the seabed submerged buoy and accurately positions and uninterruptedly carries out real-time service on the underwater acoustic transponder;

(f) various optical fibers in the armored photoelectric composite cable are connected with a composite modulation and demodulation instrument in the sea surface buoy, so that the water temperature, the pressure, the density and the salt saturation of seawater from the sea surface to the seabed submerged buoy position along the armored photoelectric composite cable are measured in real time and uninterruptedly;

(g) utilizing the water temperature, pressure, density and salt saturation data of the seawater from the sea surface to the seabed submerged buoy position measured by all the armored photoelectric composite cables to calculate the real-time three-dimensional water temperature, pressure, density and salt saturation value of the seawater in the water body of the whole measurement region by interpolation;

(h) calculating real-time three-dimensional water temperature, pressure, density and salt saturation value of seawater in the water body of the submarine seismic data acquisition region by using the step (g) according to the accurately positioned position of each submarine four-component node seismic data acquisition instrument and the underwater sound transmission track connecting line between each submarine four-component node seismic data acquisition instrument and each submarine submerged buoy, and performing real-time correction on the underwater sound speed on each underwater sound transmission track from the submarine submerged buoy to each submarine four-component node seismic data acquisition instrument;

(i) and (3) correcting the positioning and time service data of each seabed four-component node seismic data acquisition instrument in real time by using the real-time correction value of the underwater sound velocity carried out by each underwater sound propagation track from the seabed submerged buoy to each seabed four-component node seismic data acquisition instrument, so as to ensure that the positioning and time service precision of each seabed four-component node seismic data acquisition instrument meets the measurement error requirement in the measurement work area.

The optical fiber geophone has the advantages of high sensitivity, wide frequency band, good high-frequency response, flat frequency characteristic response, linear phase change, good technical parameter consistency, stable and reliable performance, no electricity or passive, corrosion resistance and high temperature resistance, and is the development direction of the geophone technology. Compared with the conventional detector, the optical fiber detector has higher sensitivity and better high-frequency response characteristic, and can realize multi-channel, large-data-volume and high-speed transmission. And because the front end does not have electronic components, the high-voltage-resistant cable has higher reliability, high temperature and high voltage resistance, does not need power supply, is waterproof and corrosion-resistant, can be laid for a long time, resists electromagnetic interference and has small channel crosstalk.

According to the seabed four-component node seismic data acquisition system and the data acquisition method thereof, the optical fiber sensor has the advantages of high sensitivity, wide frequency band, good high-frequency response, flat frequency characteristic response, linear phase change, good technical parameter consistency, stable and reliable performance, no electricity or passive, corrosion resistance and high temperature resistance, and is the development direction of the seismic detector technology. Compared with the conventional detector, the optical fiber detector has higher sensitivity and better high-frequency response characteristic, and can realize multi-channel, large-data-volume and high-speed transmission. And because the front end does not have electronic components, the high-voltage-resistant cable has higher reliability, high temperature and high voltage resistance, does not need power supply, is waterproof and corrosion-resistant, can be laid for a long time, resists electromagnetic interference and has small channel crosstalk. The defects of low sensitivity, small dynamic range, limited signal frequency band and large power consumption of the conventional electronic detector and the conventional piezoelectric hydrophone can be overcome.

Drawings

FIG. 1 is a schematic diagram of the arrangement of the acquisition system of the present invention.

Detailed Description

In order to facilitate understanding of the invention, the seabed four-component node seismic data acquisition system based on underwater acoustic signal positioning time service of the invention is explained and described in more detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings illustrate preferred embodiments of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. They are not to be construed as limiting the invention but merely as exemplifications, while the advantages thereof will be more clearly understood and appreciated by way of illustration.

FIG. 1 is a schematic layout diagram of a seabed four-component node seismic data acquisition system, which comprises a seabed submerged buoy 1, a sea surface buoy 4, an armored photoelectric composite cable 10, a seabed four-component node seismic data acquisition instrument 11 and a sea surface seismic source ship 13;

a plurality of the ocean bottom four-component node seismic data acquisition instruments 11 are arranged in an ocean bottom seismic data acquisition work area according to a pre-designed measurement grid;

the submarine submerged buoy 1 is arranged around a submarine seismic data acquisition work area, and an underwater acoustic signal emission source 2 and a rechargeable battery 3 of a long baseline or short baseline or ultra-short baseline positioning system are arranged in the submarine submerged buoy;

the sea surface buoy 4 is internally provided with a GPS and Beidou satellite signal receiving antenna 5, a solar cell panel 6, a photoelectric conversion module 7 and a composite modulation and demodulation instrument 8;

the armored photoelectric composite cable 10 is internally provided with a cable 9, and the outer layer of the armored photoelectric composite cable is wrapped with a high-strength sheath woven by Kevlar fibers or armored by twisting one or more layers of stainless steel wires; the cable 9 comprises a continuous grating optical fiber, a single mode optical fiber, a multimode optical fiber, a coaxial cable and a twisted pair power supply line;

the submarine submerged buoy (1) corresponds to the sea surface buoys (4) one by one and is connected through an armored photoelectric composite cable (10);

the top of the seabed four-component node seismic data acquisition instrument 11 is provided with a water sound transponder 12 which can be a conventional four-component node seismic data acquisition instrument with a built-in three-component conventional wave detector and a piezoelectric hydrophone or an optical fiber four-component node seismic data acquisition instrument;

the submarine optical fiber four-component seismic data acquisition instrument 11 comprises a pressure-bearing cabin, wherein a three-component optical fiber detector, an optical fiber sound pressure hydrophone, a three-component attitude sensor, a semiconductor light source, an internal photoelectric conversion module, a modulation and demodulation module, a preposed amplification and A/D conversion module, a data storage module and a rechargeable battery module are arranged in the pressure-bearing cabin;

the marine surface seismic source vessel 13 is seismic source fired below the water surface by a stern towed air gun seismic source 14.

The data acquisition method of the seabed four-component node seismic data acquisition system comprises the following steps:

(a) firstly, four submarine submerged beacons 1 are put around a submarine seismic data acquisition work area, the tail end of an armored photoelectric composite cable 10 is connected with the submarine submerged beacons 1, and the head end of the armored photoelectric composite cable is connected with a sea surface buoy 4;

(b) the seabed four-component node seismic data acquisition instrument 11 is thrown to the seabed of a seabed seismic data acquisition work area by using a rope, a steel cable or an ROV according to a pre-designed network measurement coordinate;

(c) starting instruments in the submarine submerged buoy 1 and the sea surface buoy 4, and sending positioning and time service signals received by a GPS or Beidou satellite signal receiving antenna 5 in the sea surface buoy 4 to the submarine submerged buoy 1 through a photoelectric composite cable;

(d) the submarine submerged buoy 1 transmits the positioning and time service signals to the water area around the submarine four-component node seismic data acquisition instrument 11 through the underwater acoustic signal emission source 2;

(e) the underwater acoustic responder 12 arranged at the top of each seabed four-component node seismic data acquisition instrument 11 in the measurement work area respectively receives positioning and time service signals emitted by seabed submerged beacons around the measurement work area, and accurately positions and uninterruptedly carries out real-time service on the underwater acoustic responder;

(f) various optical fibers in the armored photoelectric composite cable 10 are connected with a composite modulation and demodulation instrument 8 in the sea surface buoy, so that the water temperature, the pressure, the density and the salt saturation of seawater from the sea surface to the seabed submerged buoy position along the armored photoelectric composite cable 10 can be measured in real time and uninterruptedly;

(g) the real-time three-dimensional water temperature, pressure, density and salt saturation value of seawater in the water body of the full measurement work area are calculated through interpolation by utilizing the water temperature, pressure and density and the salt saturation data of the seawater from the sea surface to the seabed submerged buoy position measured by all armored photoelectric composite cables 10 connected between the sea surface buoy 4 and the seabed submerged buoy 1 at the periphery of the measurement work area;

(h) calculating real-time three-dimensional water temperature, pressure, density and salt saturation value of seawater in the water body of the whole measurement region by using the step (g) according to the accurately positioned position of each seabed four-component node seismic data acquisition instrument 11 and the underwater sound transmission track connecting line between each seabed four-component node seismic data acquisition instrument 11, and performing real-time underwater sound speed correction on the underwater sound transmission track from each seabed submerged buoy 1 to each seabed four-component node seismic data acquisition instrument 11;

(i) and (3) correcting the positioning and time service data of each seabed four-component node seismic data acquisition instrument 11 in real time by using the real-time correction value of the underwater sound velocity carried out by each underwater sound propagation track from the seabed submerged buoy 1 to each seabed four-component node seismic data acquisition instrument 11, and ensuring that the positioning and time service precision of each seabed four-component node seismic data acquisition instrument 11 meets the measurement error requirement in the measurement work area.

The seabed four-component node seismic data acquisition system has the advantages of high sensitivity, wide frequency band, good high-frequency response, flat frequency characteristic response, linear phase change, good technical parameter consistency, stable and reliable performance, no electricity or passive, corrosion resistance and high temperature resistance, and is the development direction of the seismic detector technology. Compared with the conventional detector, the optical fiber detector has higher sensitivity and better high-frequency response characteristic, and can realize multi-channel, large-data-volume and high-speed transmission. And because the front end does not have electronic components, the high-voltage-resistant cable has higher reliability, high temperature and high voltage resistance, does not need power supply, is waterproof and corrosion-resistant, can be laid for a long time, resists electromagnetic interference and has small channel crosstalk. The defects of low sensitivity, small dynamic range, limited signal frequency band and large power consumption of the conventional electronic detector and the conventional piezoelectric hydrophone can be overcome.

The invention provides a seabed four-component node-based seismic data acquisition system and a data acquisition method thereof, overcomes the defects that the prior art can not accurately position and time service in real time during operation of a seabed node seismic instrument, replaces an atomic clock chip which is expensive and can not avoid time service drift, greatly reduces the manufacturing cost of the seabed four-component node seismic data acquisition system, lays a good foundation for large-scale popularization and application of seabed four-component seismic data acquisition, and provides powerful technical support.