RU2791851C1 - Listening submarine sonar - Google Patents

Abstract

FIELD: hydroacoustics.

SUBSTANCE: invention relates in particular to methods and devices for detecting marine targets by their noise emission in the low sound and infrasonic frequency ranges using a direction-finding station with linear extended onboard antennae (LEOA). Listening submarine sonar (LSS) contains hydroacoustic receivers (HAR), and to ensure the spherical directional characteristic of which, each HAR, which is part of the LEOA, is a structure of two piezoceramic transducers connected in such a way that their axes are mutually perpendicular. As a result, the HAR become non-directional (omnidirectional) in both planes. To give the HARs high vibration resistance with respect to the vibrations of the hull of the submarine, the LEOA is attached to the hull of the submarine through a vibration-isolating layer; each HAR is placed in a sealed chamber with a polymer filler. A fairing with high sound transparency and at the same time mechanical strength is used. Signal pre-processing units are built into the LEOA and are located in close proximity to the HAR.

EFFECT: ensuring the LEOA operability under the influence of ship noise, vibrations and pickups.

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Description

The invention relates to the field of hydroacoustics, and in particular to methods and devices for detecting marine targets by their noise emission in the low sound and infrasound frequency ranges.

One of the conditions for ensuring the combat stability of a submarine (sub) is the timely detection and classification of torpedoes and anti-submarine helicopters and aircraft (hereinafter referred to as air targets) in the entire circular sector of course and elevation angles. Since the characteristic classification features of torpedoes and air targets are in the region of low sonic and infrasonic frequencies (below 500 Hz), submarines use a noise direction finding station (SHPS) with a flexible extended towed antenna (GPBA) to solve this problem [1]. Figure 1 shows the aft end of the submarine with the released GPBA.

In addition to solving the problem of detecting targets in the low sound frequency range, NLS with GPBA provide an overview of the space in the aft heading angles, shaded for NLS with shipborne bow sonar antennas.

However, SPS with GPBA has a number of individual disadvantages that affect the effectiveness of its use.

The NPS described in the utility model patent [2] was chosen as a prototype. To eliminate the shortcomings and also to passively determine the distance to the target by the triangulation method in the low sound frequency range, in this utility model, it is proposed, in addition to the GPBA, to install linear extended antennas along both sides of the submarine (hereinafter we will call them linear extended onboard antennas or abbreviated LPBA). Schematically LPBA starboard shown in Fig.2.

Figure 3 shows a block diagram of the prototype device. It includes:

- two LPBA 2, installed along the right and left sides of the submarine, respectively;

- two blocks 3 for transmitting signals to the solid hull of the submarine, connected to the outputs of the LPBA 2 of the right and left sides;

- two blocks 4 of signal processing connected to blocks 3 of signal transmission to the strong hull of the right and left sides of the submarine;

- device 5 for displaying the results of signal processing and control of the SHPS, connected to the outputs of blocks 4 for processing signals of the right and left sides of the submarine.

The work of the NPS claimed in [2] is as follows. LPBA 2 of the right and left sides receive hydroacoustic signals in the low sound and infrasonic frequency ranges and through the signal transmission units into the robust housing 3 transmit them to the input of the signal processing unit 4, where, by forming the antenna directivity characteristics, the distribution of the energy of the signals received by the antennas of the right and left sides. The generated distributions for the starboard and port sides are jointly displayed on the indicator of the device 5 for displaying the results of signal processing and NPS control. The SHPS operator, visually analyzing the distribution of the energy of the signals received by the LPBA of the starboard and port sides, according to the bearings, detects targets and determines their bearings.

Due to the attachment of the LPBA to the hull of the submarine, their shape does not change when the submarine is maneuvering, which ensures the constant efficient operation of the SHPS. The presence of LPBA does not impose restrictions on the speed of the submarine. The shielding of the LPBA by the hull of the submarine limits the field of view of each LPBA in the horizontal plane and thus provides an unambiguous determination of the bearing of the detected target.

It should be noted that the design of the LPBA is not described in [2] or in other available sources. At the same time, the installation along the sides of the submarine imposes a number of specific requirements on the LPBA. In particular:

- LPBA must have high vibration resistance in relation to the vibrations of the submarine hull, transmitted to the LPBA through the elements of its fastening to the side of the submarine;

- for simultaneous illumination of the entire hemisphere bounded by the submarine hull, hydroacoustic receivers (HAR), which are part of the LPBA, must have a spherical directivity characteristic (HN), which becomes hemispherical when the HAR is installed on board the submarine due to shielding by the submarine;

- LPBA should be covered with a fairing with high sound transparency and sufficient mechanical strength;

- measures must be taken to exclude electrical and electromagnetic pickups on the cable connecting the LPBA with the signal processing unit, located in the solid housing of the submarine.

The technical problem to be solved is to increase the operational characteristics of a noise direction finding station with a LPBA for an underwater vehicle designed to detect targets in the low sound and infrasonic frequency ranges.

EFFECT: ensuring the LPBA operability under the influence of shipborne noise, vibrations and pickups.

The design of the proposed device is illustrated in Fig. 4-7.

Brief description of drawings:

1 - GPBA;

2 - LPBA;

3 - signal transmission unit in a robust housing;

4 - signal processing unit;

5 - a device for displaying the results of signal processing and control of the NPS;

6 - vibration isolation layer;

7 - hermetic chamber with polymer filler "Gelur";

8 - hydroacoustic receiver (HAP);

9 - rubber fairing (hereinafter referred to as the fairing);

10 - hydroacoustic coating submarine;

11 - piezoceramic transducers;

12 - HAP flanges;

13 - mounting substrate for piezoceramic transducers.

14 - body part of the LPBA;

15 - mounting support;

16 - guide;

17 - cable with electrical and optical cores;

18 - bonk;

19 - signal pre-processing block.

LPBA (figures 4 and 7) consists of a receiving part, connected by means of bonnets 18 to the side of the submarine through a vibration-insulating layer 6 and a rubber fairing 9.

The composition of the receiving part of the LPBA of each side of the submarine includes (Fig.7) hydroacoustic receivers 8 (the design of one HAP is shown in Fig.5), using a cable laid along the side of the submarine with electrical and optical conductors 17, connected to the signal pre-processing unit 19, which, in turn, are connected to a signal transmission device in a robust housing 4.

HAP 8 (Fig.5) is placed in a sealed chamber with a polymer filler "Gelur" 7 construction of two piezoceramic transducers 11, connected in such a way that their axes are mutually perpendicular.

Signal pre-processing unit 19 is an electronic device that performs amplification, frequency filtering and analog-to-digital conversion of signals coming from the output of HAP 8.

The specified technical result is achieved by the following technical solutions.

1) To ensure a spherical directivity characteristic, each HAP 8, which is part of the LPBA 2, is a structure of two piezoceramic transducers 11, connected in such a way that their axes are mutually perpendicular (Fig.5). As a result, HAP 8 become non-directional (omni-directional) in both planes. As an illustration, Fig. 6 shows the directional characteristics of the HAP measured in the hydroacoustic basin in the horizontal and vertical planes at a frequency of 3.15×f0 (where f0 is a certain reference frequency), which confirm the omnidirectionality of the HAP.

2) To give the HAP high vibration resistance in relation to the vibrations of the hull of the submarine:

- LPBA 2 are attached to the body of the submarine through the anti-vibration layer 6 (figure 4 and 7);

- HAP 8 is placed in a sealed chamber with a polymer filler 7 (figure 4 and 7).

3) As a fairing 9, which has high sound transparency and at the same time mechanical strength, used rubber brand 51-2708 with a thickness of about 50 mm with a strength of 136 kg/cm ² (figure 4 and 7).

4) To prevent distortion of the signals received by HAP 8 due to electromagnetic pickups on the cable 17 connecting HAP 8 with signal processing device 4, located in a solid housing of the submarine, signal pre-processing units 19 are built into the LPBA and are located in close proximity to the HAP 8 ( 4 and 7). Prevention of distortion of signals received by HAP 8 is achieved by amplifying them and converting them into digital form, which, as is known, is not subject to pickups, especially when using noise-correcting coding.

Thus, the claimed technical result - ensuring the LPBA operability under the influence of ship noise, vibrations and pickups - can be considered achieved.

The feasibility of the claimed invention is confirmed by the creation of the LPBA model and its testing.

Information sources:

1. Koryakin Yu.A., Smirnov S.A., Yakovlev G.V. Ship hydroacoustic equipment. Status and current problems // St. Petersburg: Nauka, 2004.

2. RF patent No. 122494.

Claims (1)

Noise-direction-finding station for a submarine (submarine), including two linear extended on-board antennas (LPBA) of the right and left sides placed onboard and attached to it, each of which consists of a cable covered with a fairing with hydroacoustic receivers (HAP) connected to it, two transmission units signals into the strong hull of the submarine, connected to the outputs of the LPBA of the starboard and port sides, two signal processing units connected to the outputs of the signal transmission units into the robust hull of the submarines of the starboard and port sides, a device for displaying the results of signal processing and controlling the direction-finding station, connected to the outputs of the processing units signals of the right and left sides, characterized in that each LPBA is attached to the submarine hull through a vibration-insulating layer of rubber composition, each HAP is a structure placed in a sealed chamber with a polymer filler, consisting of two piezoceramic transducers with mutually perpendicular axes, a fairing made of rubber, each LPBA additionally includes a signal pre-processing unit that performs amplification, frequency filtering and analog-to-digital conversion of HAP signals.

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