A convenient measurement system and method for the sound field of a ship radiation space

Abstract

The invention discloses a ship radiation space sound field measurement system and a measurement method thereof, comprising: five hydrophone components, a navigator, a data acquisition instrument and a display and control device; each hydrophone component is provided with a hydrophone; the hydrophones of the five hydrophone components are electrically connected to the input end of the data acquisition instrument, and the output end of the data acquisition instrument is electrically connected to the display and control device; the five hydrophone components are arranged in a straight line; the navigator is installed just above the hydrophone of the hydrophone component in the middle, and is used for transmitting navigation signals to guide the ship to navigate along the straight main route A; the five hydrophones are respectively used for measuring the sound signals of the radiation noise emitted by the ship, and converting the sound signals into electrical signals; after the data acquisition instrument acquires the electrical signals of the five hydrophones, the electrical signals are forwarded to the display and control device, and the display and control device solves the electrical signals; the invention only needs one voyage to realize the radiation space sound field measurement of the ship at 12 azimuths distributed at equal intervals.

Description

Technical Field

[0001] The invention belongs to the technical field of ship radiation noise measurement, and in particular relates to a ship radiation space sound field measurement system and a measurement method thereof. Background Art

[0002] The sound field radiated by a ship is one of the important indicators of its concealment, which is used to evaluate the danger of a ship being detected by enemy sonar and attacked by underwater weapons. The noise radiated outward by a ship as a sound source has directional characteristics, that is, the energy of the radiated noise is unevenly distributed in space, and the sound source level is related to the direction of the observation point. Accurately grasping the directivity of the level of radiated noise from a ship is of great guiding significance for avoiding enemy sonar detection and underwater weapon attacks.

[0003] Since it is difficult to measure the directivity of ship radiated noise, the traditional measurement method has very high requirements on the maneuvering mode of the ship. The traditional measurement method is usually equipped with a navigation array and a measurement array. The ship is towed by the navigation array and passes through the measurement array at different headings. The noise level of the ship's radiated noise in different directions on the horizontal plane can be obtained, that is, the horizontal directivity of the radiated noise. Assuming that the horizontal plane is divided into 12 directions at intervals of 30°, the noise level of the ship at 12 azimuths is measured, requiring the ship to be towed by the navigation array and maneuvered 12 times through the measurement array. The improved scheme can reduce the number of ship maneuvers to 5 by improving the measurement system and optimizing the ship's maneuvering mode. The improved scheme still has high requirements on the ship's maneuvering mode.

[0004] The above-mentioned ship radiation space sound field measurement method not only has high requirements on the ship's maneuvering mode, but also has a large number of maneuvers, consuming a large amount of power energy costs. Summary of the invention

[0005] In view of this, the present invention provides a ship radiation space sound field measurement system and a measurement method thereof. By adopting the measurement system and the measurement method, the radiation space sound field measurement of the ship at 12 azimuths distributed at equal intervals can be achieved in just one voyage.

[0006] The present invention is achieved through the following technical solutions:

[0007] A ship radiation space sound field measurement system, comprising: five hydrophone components, a navigator, a data acquisition instrument and a display and control device;

[0008] Each hydrophone assembly is provided with a hydrophone; the hydrophones of the five hydrophone assemblies are electrically connected to the input end of the data acquisition instrument, and the output end of the data acquisition instrument is electrically connected to the display and control device;

[0009] The five hydrophone assemblies are arranged in a straight line, and the order of the five hydrophone assemblies is the first hydrophone assembly, the second hydrophone assembly, the third hydrophone assembly, the fourth hydrophone assembly and the fifth hydrophone assembly; wherein the spacing between the first hydrophone assembly and the second hydrophone assembly, and between the fourth hydrophone assembly and the fifth hydrophone assembly is L, and the spacing between the second hydrophone assembly and the third hydrophone assembly, and between the third hydrophone assembly and the fourth hydrophone assembly is 2L;

[0010] The navigator is installed directly above the hydrophone of the third hydrophone assembly, and is used to transmit navigation signals to guide the ship to sail along the straight main route A; the main route A is perpendicular to the straight line where the five hydrophone assemblies are located; there are five azimuth solution points arranged at equal intervals on the main route A, in the order of P1, P2, P3, P4, and P5; among them, P3 is located directly below the third hydrophone assembly; the distance between two adjacent azimuth solution points is When the ship passes through the azimuth solution points P1, P2, P3, P4, and P5 in sequence along the main route A, the five azimuth solution points can cover 12 azimuths equally spaced by the ship; the five hydrophones are respectively used to measure the acoustic signals of the radiated noise emitted by the ship, and convert the acoustic signals into electrical signals; after the data acquisition instrument collects the electrical signals of the five hydrophones, the electrical signals are forwarded to the display and control device, and the display and control device solves the electrical signals, converts the sound pressure level of the radiated noise of the electrical signals to 1 meter, and expresses it in the form of polar coordinates, so as to obtain a schematic diagram of the radiation space sound field of the ship, and complete the spatial sound field measurement of the ship in 12 directions.

[0011] Furthermore, the measurement system also includes a rangefinder; the rangefinder is installed directly below the hydrophone of the third hydrophone assembly, and is used to record the distance information between itself and the ship, and send the distance information to the data acquisition instrument.

[0012] Furthermore, the measurement system also includes a measurement ship; the data acquisition instrument and the display and control equipment are both installed on the measurement ship.

[0013] Furthermore, the hydrophone assembly also includes: a counterweight, a cable and a buoy; the buoy, the hydrophone and the counterweight are sequentially connected in series from top to bottom via the cable, and the cable is in a vertical state.

[0014] Furthermore, the value range of L is 10 meters to 20 meters.

[0015] Furthermore, the main route A is located 5 to 10 meters directly below the hydrophone of the third hydrophone assembly.

[0016] Further, the hydrophone of the first hydrophone assembly is hydrophone one; the hydrophone of the second hydrophone assembly is hydrophone two; the hydrophone of the third hydrophone assembly is hydrophone three; the hydrophone of the fourth hydrophone assembly is hydrophone four; the hydrophone of the fifth hydrophone assembly is hydrophone five;

[0017] The azimuth angle calculation point P1 covers a total of three azimuth angles, namely, 0° and ±30°. That is, when the ship is at the azimuth angle calculation point P1, the angle between the ship and the hydrophone 3 is 0°, the angle between the ship and the hydrophone 2 is 30°, and the angle between the ship and the hydrophone 4 is -30°.

[0018] The azimuth angle calculation point P2 covers a total of 2 azimuth angles of ±60°, that is, when the ship is at the azimuth angle calculation point P2, the angle between the ship and the hydrophone 1 is 60°, and the angle between the ship and the hydrophone 4 is -60°;

[0019] The azimuth angle calculation point P3 covers a total of 2 azimuth angles of ±90°, that is, when the ship is at the azimuth angle calculation point P3, the angle between the ship and hydrophone 1 is 90°, and the angle between the ship and hydrophone 4 is -90°;

[0020] The azimuth angle calculation point P4 covers a total of 2 azimuth angles of ±120°, that is, when the ship is at the azimuth angle calculation point P4, the angle between the ship and hydrophone 1 is 120°, and the angle between the ship and hydrophone 4 is -120°;

[0021] The azimuth angle calculation point P5 covers a total of three azimuth angles of ±150° and 180°, that is, when the ship is at the azimuth angle calculation point P5, the angle between the ship and hydrophone two is 150°, the angle between the ship and hydrophone four is -150°; the angle between the ship and hydrophone three is 180°.

[0022] A method for measuring a ship radiation space sound field measurement system, the specific steps are as follows:

[0023] Step 1: After the ship maneuvers to the set position of the main route A, the navigator is turned on. Under the guidance of the navigation signal, the ship keeps sailing in a straight line along the main route A and passes under the navigator, while the data acquisition device is turned on;

[0024] Step 2: During the movement of the ship along the main route A, five hydrophones measure the acoustic signals of the radiated noise when the ship passes through the azimuth solution points P1, P2, P3, P4, and P5;

[0025] Step three, calculate the radiation noise level of the ship and the five hydrophones at 12 azimuths corresponding to the above five azimuth solution points through the display and control equipment, convert it to 1 meter, and display it in the form of polar coordinates to obtain the directivity diagram of the ship's spatial sound field.

[0026] Furthermore, the measurement system also includes a rangefinder; the rangefinder records the distance between the ship and the rangefinder in real time;

[0027] Since the ship will deviate during its movement along the main route A, the actual navigation track of the ship is the main route A'. Therefore, the main route A' is used to replace the main route A. The main route A' of the ship can be calculated on the display and control device according to the real-time data of the rangefinder collected by the data acquisition instrument, the depth of the hydrophone and the depth and speed information sent by the ship itself. The azimuth solution point P1, azimuth solution point P2, azimuth solution point P3, azimuth solution point P4 and azimuth solution point P5 are re-marked on the main route A'.

[0028] Furthermore, before step one, the measurement system is deployed, installed and debugged.

[0029] Beneficial effects:

[0030] (1) During the measurement of the sound field in the radiation space of a ship, the present invention has low requirements on the maneuvering mode of the ship. The ship only needs to maneuver once at a constant speed in a straight line to complete the sound field test in the radiation space in 12 directions of the ship. Compared with the existing test systems and methods, the present invention can significantly improve the measurement efficiency and greatly reduce the power energy consumption of the ship.

[0031] (2) The present invention is mainly applicable to the measurement and evaluation of the spatial directivity of the ship's radiated sound field, and can provide a scientific basis for the development of ship acoustic stealth technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the system composition of the present invention;

[0033] Figure 2 A schematic diagram showing the distribution of the main routes and azimuth angle solution points of the ship maneuvering of the present invention;

[0034] Figure 3 A schematic diagram of the directivity of the ship's spatial sound field measured by the system of the present invention;

[0035] Among them, 1-a-counterweight one, 1-b-counterweight two, 1-c-counterweight three, 1-d-counterweight four, 1-e-counterweight five, 2-rangefinder, 3-a-hydrophone one, 3-b-hydrophone two, 3-c-hydrophone three, 3-d-hydrophone four, 3-e-hydrophone five, 4-navigator, 5-a-cable one, 5-b-cable two, 5-c-cable three, 5-d-cable four, 5-e-cable five, 6-a-buoy one, 6-b-buoy two, 6-c-buoy three, 6-d-buoy four, 6-e-buoy five, 7-cable, 8-data acquisition instrument, 9-display and control equipment, 10-survey ship, 11 ship. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0037] This embodiment provides a ship radiation space sound field measurement system, see attached Figure 1 , including: five hydrophone components, a rangefinder 2, a navigator 4, a cable 7, a data acquisition instrument 8, a display and control device 9 and a survey ship 10;

[0038] Each of the hydrophone assemblies comprises: a counterweight, a hydrophone, a cable and a buoy; the buoy, the hydrophone and the counterweight are connected in series from top to bottom via the cable; the counterweight is used to ensure that the cable is in a vertical state; the hydrophones of the five hydrophone assemblies are electrically connected to the input end of the data acquisition instrument 8 via the cable 7, and the output end of the data acquisition instrument 8 is electrically connected to the display and control device 9 via the cable 7; the data acquisition instrument 8 and the display and control device 9 are both installed on the survey ship 10; the data acquisition instrument 8 is used to collect the hydroacoustic signals obtained by the measurement of the hydrophone, and the display and control device 9 is used to process, analyze and display the hydroacoustic signals collected by the data acquisition instrument 8;

[0039] Under the action of the water flow, the five hydrophone components are unfolded along a straight line and arranged in a straight line, so that the order of the five hydrophone components is the first hydrophone component, the second hydrophone component, the third hydrophone component, the fourth hydrophone component and the fifth hydrophone component; the counterweight, hydrophone, cable and buoy of the first hydrophone component are respectively counterweight 1-a, hydrophone 1 3-a, cable 1 5-a and buoy 1 6-a; the counterweight, hydrophone, cable and buoy of the second hydrophone component are respectively counterweight 2 1-b, hydrophone 2 3-b, cable 2 5-b and buoy 2 6-b; the counterweight, hydrophone, cable and buoy of the third hydrophone component are respectively counterweight 3 1-c, hydrophone 3 3-c, cable 5-d and buoy 6-d. c, cable three 5-c and buoy three 6-c; the counterweight, hydrophone, cable and buoy of the fourth hydrophone assembly are counterweight four 1-d, hydrophone four 3-d, cable four 5-d and buoy four 6-d respectively; the counterweight, hydrophone, cable and buoy of the fifth hydrophone assembly are counterweight five 1-e, hydrophone five 3-e, cable five 5-e and buoy five 6-e respectively; wherein, the distance between hydrophone one 3-a and hydrophone two 3-b, hydrophone four 3-d and hydrophone five 3-e is L, the distance between hydrophone two 3-b and hydrophone three 3-c, hydrophone three 3-c and hydrophone four 3-d is 2L, and the value range of L is 10 meters to 20 meters;

[0040] The rangefinder 2 and the navigator 4 are both installed on the cable 3 5-c, the rangefinder 2 is located between the counterweight 3 1-c and the hydrophone 3 3-c, the navigator 4 is located between the hydrophone 3 3-c and the buoy 3 6-c, and the depth of the rangefinder 2 and the navigator 4 from the water surface is ensured to be constant;

[0041] The counterweight 3 1-c, the rangefinder 2, the navigator 4, the cable 3 5-c and the buoy 3 6-c constitute a navigation and ranging unit, which is used to guide the ship 11 to pass directly below the five hydrophone assemblies along the maneuvering trajectory; the navigator 4 is used to transmit a navigation signal to guide the ship 11 to sail in a single direction, and the rangefinder 2 is used to record the distance information between itself and the ship 11, and send the distance information to the data acquisition device 8;

[0042] The maneuvering trajectory is the main route A which is a straight line 5 to 10 meters below the hydrophone 3-c; see attached Figure 2 , the main route A is perpendicular to the straight line where the five hydrophone assemblies are located; there are five azimuth solution points arranged at equal intervals on the main route A, in the order of P1, P2, P3, P4, and P5; under the guidance of the navigator 4, the ship 11 passes through the azimuth solution points P1, P2, P3, P4, and P5 in sequence along the main route A; among them, P3 is located directly below the hydrophone 3-c, that is, on the straight line where the cable 3-c is located; the distance between two adjacent azimuth solution points is

[0043] The azimuth angle calculation point P1 covers a total of three azimuth angles, namely, 0° and ±30°. That is, when the ship 11 is at the azimuth angle calculation point P1, the height difference between the ship 11 and the hydrophones of the five hydrophone assemblies in depth is ignored. The angle between the ship 11 and the hydrophone 3-c is 0°, the angle between the ship 11 and the hydrophone 2 3-b is 30°, and the angle between the ship 11 and the hydrophone 4 3-d is -30°.

[0044] The azimuth angle calculation point P2 covers a total of 2 azimuth angles of ±60°, that is, when the ship 11 is at the azimuth angle calculation point P2, the height difference between the ship 11 and the hydrophones of the five hydrophone assemblies in depth is ignored, and the angle between the ship 11 and the hydrophone 1 3-a is 60°, and the angle between the ship 11 and the hydrophone 4 3-e is -60°;

[0045] The azimuth angle calculation point P3 covers a total of 2 azimuth angles of ±90°, that is, when the ship 11 is at the azimuth angle calculation point P3, the height difference between the ship 11 and the hydrophones of the five hydrophone assemblies in depth is ignored, and the angle between the ship 11 and the hydrophone 1 3-a is 90°, and the angle between the ship 11 and the hydrophone 4 3-e is -90°;

[0046] The azimuth angle calculation point P4 covers a total of 2 azimuth angles of ±120°, that is, when the ship 11 is at the azimuth angle calculation point P4, the height difference between the ship 11 and the hydrophones of the five hydrophone assemblies in depth is ignored, and the angle between the ship 11 and the hydrophone 1 3-a is 120°, and the angle between the ship 11 and the hydrophone 4 3-e is -120°;

[0047] The azimuth angle calculation point P5 covers a total of three azimuth angles of ±150° and 180°, that is, when the ship 11 is at the azimuth angle calculation point P5, the height difference between the ship 11 and the hydrophones of the five hydrophone assemblies in depth is ignored, and the angle between the ship 11 and the hydrophone 2 3-b is 150°, and the angle between the ship 11 and the hydrophone 4 3-d is -150°; the angle between the ship 11 and the hydrophone 3 3-c is 180°;

[0048] The five azimuth solution points can cover 12 azimuths of the ship 11 divided at equal intervals; the ship 11 will emit radiated noise; the five hydrophones are used to measure the acoustic signals of the radiated noise of the ship 11 at 12 azimuths, and convert the acoustic signals into electrical signals; after the data acquisition instrument 8 collects the electrical signals of the five hydrophones, it forwards the electrical signals to the display and control device 9, and the display and control device 9 solves the electrical signals, converts the sound pressure level of the radiated noise of the electrical signals to 1 meter, and expresses it in the form of polar coordinates, so as to obtain a schematic diagram of the radiation space sound field of the ship 11 and display it, as shown in FIG. Figure 3 shown.

[0049] Based on the above-mentioned measurement method of the ship radiation space sound field measurement system, the specific steps are as follows:

[0050] Step 1: deploying, installing and debugging the measurement system. After the measurement system is installed, the test system is debugged;

[0051] Step 2: The ship 11 maneuvers to the outside of the azimuth solution point P1 of the main route A (i.e., the side away from the azimuth solution point P2), and dives to a specified depth. To prevent collision, the navigation depth of the ship 11 is greater than the counterweight depth of the hydrophone assembly.

[0052] Step 3: Turn on the navigator 4 and the rangefinder 2. The ship 11 travels in the direction of the navigator 4 under the guidance of the navigation signal. The rangefinder 2 records the distance between the ship 11 and the rangefinder 2 in real time.

[0053] Step 4: When the ship 11 sails to the specified distance from the rangefinder 2, the navigator 4 is turned off, and the ship 11 sails in a straight line along the main route A and passes under the navigator 4. At the same time, the data collector 8 is turned on to record the sound pressure level of the radiated noise when the ship 11 passes through the main route A; after the ship 11 sails to the specified distance, the data collector 8 is turned off;

[0054] Among them, since the ship 11 may deviate slightly during its movement along the main route A, the actual navigation track of the ship 11 is the main route A', so the main route A is replaced by the main route A', and; according to the real-time data of the rangefinder 2 collected by the data acquisition device 8, the depth of the hydrophone and the depth and speed information emitted by the ship 11 itself, the main route A' of the ship 11 can be calculated on the display and control device 9;

[0055] Step 5: re-mark the azimuth solution points P1, P2, P3, P4 and P5 on the main route A'; the ship 11 only needs one voyage to cover the spatial sound field in 12 directions, as follows:

[0056] The acoustic signals of the radiated noise when the ship 11 passes through the azimuth solution points P1, P2, P3, P4, and P5 are measured by five hydrophones; when the ship 11 passes through the azimuth solution point P1, the radiated sound fields at 0°, 30°, and -30° are calculated by the test data of hydrophone three 3-c, hydrophone two 3-b, and hydrophone four 3-d; when the ship 11 passes through the azimuth solution point P2, the radiated sound fields at 60° and -60° are calculated by the test data of hydrophone one 3-a and hydrophone five 3-e; When the azimuth solution point P3 is reached, the radiated sound fields at 90° and -90° are calculated from the test data of the hydrophone 1 3-a and the hydrophone 5 3-e; when the ship 11 passes through the azimuth solution point P4, the radiated sound fields at 120° and -120° are calculated from the test data of the hydrophone 1 3-a and the hydrophone 5 3-e; when the ship 11 passes through the azimuth solution point P5, the radiated sound fields at 180°, 150° and -150° are calculated from the test data of the hydrophone 3 3-c, the hydrophone 2 3-b and the hydrophone 4 3-d;

[0057] Step 6: Calculate the radiation noise level of the ship 11 and the five hydrophones at the 12 azimuths corresponding to the five azimuth solution points through the display and control device 9, convert it to 1 meter, and display it in the form of polar coordinates, so as to obtain Figure 3 The directivity diagram of the ship's spatial sound field is shown.

[0058] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A ship radiation space sound field measurement system, characterized in that: include: five hydrophone assemblies, a navigator, a data logger, and display and control equipment; Each hydrophone assembly is provided with a hydrophone; the hydrophones of the five hydrophone assemblies are electrically connected to the input end of the data acquisition instrument, and the output end of the data acquisition instrument is electrically connected to the display and control device; The five hydrophone assemblies are arranged in a straight line, and the order of the five hydrophone assemblies is the first hydrophone assembly, the second hydrophone assembly, the third hydrophone assembly, the fourth hydrophone assembly and the fifth hydrophone assembly; wherein the spacing between the first hydrophone assembly and the second hydrophone assembly, and between the fourth hydrophone assembly and the fifth hydrophone assembly is L, and the spacing between the second hydrophone assembly and the third hydrophone assembly, and between the third hydrophone assembly and the fourth hydrophone assembly is 2L; The navigator is installed directly above the hydrophone of the third hydrophone assembly, and is used to transmit navigation signals to guide the ship to sail along the straight main route A; the main route A is perpendicular to the straight line where the five hydrophone assemblies are located; there are five azimuth solution points arranged at equal intervals on the main route A, in the order of P1, P2, P3, P4, and P5; among them, P3 is located directly below the third hydrophone assembly; the distance between two adjacent azimuth solution points is When the ship passes through the azimuth solution points P1, P2, P3, P4, and P5 in sequence along the main route A, the five azimuth solution points can cover 12 azimuths equally spaced by the ship; the five hydrophones are respectively used to measure the acoustic signals of the radiated noise emitted by the ship, and convert the acoustic signals into electrical signals; after the data acquisition instrument collects the electrical signals of the five hydrophones, it forwards the electrical signals to the display and control device, and the display and control device solves the electrical signals, converts the sound pressure level of the radiated noise of the electrical signals to 1 meter, and expresses it in the form of polar coordinates, so as to obtain a schematic diagram of the radiation space sound field of the ship, and complete the spatial sound field measurement of the ship in 12 directions; The measurement system further comprises a rangefinder; the rangefinder is installed directly below the hydrophone of the third hydrophone assembly, and is used to record the distance information between itself and the ship, and send the distance information to the data acquisition instrument; The measurement system also includes a measurement ship; the data acquisition instrument and the display and control equipment are both installed on the measurement ship.

2. A ship radiation space sound field measurement system as claimed in claim 1, characterized in that: The hydrophone assembly also includes: a counterweight, a cable and a buoy; the buoy, the hydrophone and the counterweight are sequentially connected in series from top to bottom through the cable, and the cable is in a vertical state.

3. A ship radiation space sound field measurement system as claimed in claim 1 or 2, characterized in that: The value range of L is 10 meters to 20 meters.

4. A ship radiation space sound field measurement system as claimed in claim 1 or 2, characterized in that: The main route A is located 5 to 10 meters directly below the hydrophone of the third hydrophone assembly.

5. A ship radiation space sound field measurement system as claimed in claim 1 or 2, characterized in that: The hydrophone of the first hydrophone assembly is called hydrophone one; the hydrophone of the second hydrophone assembly is called hydrophone two; the hydrophone of the third hydrophone assembly is called hydrophone three; the hydrophone of the fourth hydrophone assembly is called hydrophone four; the hydrophone of the fifth hydrophone assembly is called hydrophone five; The azimuth angle calculation point P1 covers a total of three azimuth angles, namely, 0° and ±30°. That is, when the ship is at the azimuth angle calculation point P1, the angle between the ship and the hydrophone 3 is 0°, the angle between the ship and the hydrophone 2 is 30°, and the angle between the ship and the hydrophone 4 is -30°. The azimuth angle calculation point P2 covers a total of 2 azimuth angles of ±60°, that is, when the ship is at the azimuth angle calculation point P2, the angle between the ship and the hydrophone 1 is 60°, and the angle between the ship and the hydrophone 4 is -60°; The azimuth angle calculation point P3 covers a total of 2 azimuth angles of ±90°, that is, when the ship is at the azimuth angle calculation point P3, the angle between the ship and hydrophone 1 is 90°, and the angle between the ship and hydrophone 4 is -90°; The azimuth angle calculation point P4 covers a total of 2 azimuth angles of ±120°, that is, when the ship is at the azimuth angle calculation point P4, the angle between the ship and hydrophone 1 is 120°, and the angle between the ship and hydrophone 4 is -120°; The azimuth angle calculation point P5 covers a total of three azimuth angles of ±150° and 180°, that is, when the ship is at the azimuth angle calculation point P5, the angle between the ship and hydrophone two is 150°, the angle between the ship and hydrophone four is -150°; the angle between the ship and hydrophone three is 180°.

6. A measurement method for a ship radiation space sound field measurement system according to claim 1, characterized in that: The specific steps are as follows: Step 1: After the ship maneuvers to the set position of the main route A, the navigator is turned on. Under the guidance of the navigation signal, the ship keeps sailing in a straight line along the main route A and passes under the navigator, while the data acquisition device is turned on; Step 2: During the movement of the ship along the main route A, five hydrophones measure the acoustic signals of the radiated noise when the ship passes through the azimuth solution points P1, P2, P3, P4, and P5; Step three, calculate the radiation noise level of the ship and the five hydrophones at 12 azimuths corresponding to the above five azimuth solution points through the display and control equipment, convert it to 1 meter, and display it in the form of polar coordinates to obtain the directivity diagram of the ship's spatial sound field.

7. The measurement method of a ship radiation space sound field measurement system according to claim 6, characterized in that: The measuring system also includes a rangefinder; the rangefinder records the distance between the ship and the rangefinder in real time; Since the ship will deviate during its movement along the main route A, the actual navigation track of the ship is the main route A'. Therefore, the main route A' is used to replace the main route A. The main route A' of the ship can be calculated on the display and control device according to the real-time data of the rangefinder collected by the data acquisition instrument, the depth of the hydrophone and the depth and speed information sent by the ship itself. The azimuth solution point P1, azimuth solution point P2, azimuth solution point P3, azimuth solution point P4 and azimuth solution point P5 are re-marked on the main route A'.

8. The measurement method of a ship radiation space sound field measurement system according to claim 6 or 7, characterized in that: Before step one, the measurement system is deployed, installed and debugged.

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