JPH03107783A - Passive sonar device - Google Patents

Abstract

PURPOSE:To obtain the accurate horizontal distance between a diving ship and a wave receiver by providing two receivers which are arranged at the same positions of different depth and receive a direct wave and a reflected wave sent from wave transmitter, depth indicators, signal processing parts, and an arithmetic means. CONSTITUTION:The two wave receivers 1A and 1B are arranged at the same position of different depth and receive the direct wave sent from the transmitter 10 and the reflected wave from the surface of the sea. The depth indicators 2A and 2B measure the depths of the two wave receivers 1A and 1B. The signal processing parts 3A and 3B analyze the frequencies of received signals obtained by the receivers 1A and 1B to find two frequencies at which the direct wave and reflected wave has a half-wavelength phase difference. A computer 100 uses the depths of the receivers 1A and 1B obtained by the depth indicators 2A and 2B and the frequencies obtained by the processing parts 3A and 3B to calculate the depth of the transmitter 10 and the horizontal distance L from the transmitter 10 to the receivers 1A and 1B.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a passive sonar device, and in particular to a passive sonar device suitable for determining the distance between a submersible that emits sound waves with broadband component frequencies and a receiver. It is related to the device.

[Conventional technology]

FIG. 3 shows a conventional example.

In the conventional example shown in FIG. 3, one receiver 50 is used, and a depth meter 5 for measuring the depth of this receiver 50 is used.
1, a signal processing unit 52 that obtains a strong signal frequency based on the bathtub characteristics of loaf agerum, and this signal processing unit 52.
and the frequency obtained with.

It is composed of a computer 100 that inputs the depth of the receiver 50 and an estimated value of the depth of the submersible and calculates the horizontal distance between the receiver 50 and the submersible equipped with a transmitter (not shown). has been done.

The computer 100 includes an input unit 101 for inputting data.
Then, using these input data, the submersible and the receiver 5
It has a calculation unit 102 that calculates the horizontal distance from 0, and an output unit 103 that outputs the calculation result.

[Problem to be solved by the invention]

However, in the conventional example described above, since the depth of the submersible is used as an estimated value as input data, there is a problem in that an accurate horizontal distance to the receiver cannot be obtained.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a passive sonar device that can solve the problems seen in the conventional example and accurately determine the horizontal distance between a submersible and a wave receiver.

[Means to solve the problem]

In the present invention, two receivers are installed at different depths at the same location and receive the direct waves sent from the transmitter mounted on the submersible and the reflected waves at the sea surface. , a depth meter that measures the depth of these two receivers, and a frequency analysis of the received signal obtained by each receiver so that the phase difference between the direct wave and the reflected wave is half a wavelength. A signal processing section calculates the two frequencies, and the receiver depth obtained by the depth needle and each frequency obtained by the signal processing section are used to calculate the depth of the transmitter and from the transmitter to the receiver. In this way, the above-mentioned objective is achieved.

[For production]

A transmitter mounted on a submersible emits sound waves with a wide range of frequencies. Two receivers located at the same location at different depths receive the sound waves emitted from the submersible. Each receiver is
A direct wave that reaches the receiver directly from the submersible and a reflected wave that is reflected from the sea surface and reaches the receiver are received and transmitted to the signal processing section.

These received signals are transmitted to a signal processing unit, and based on the bathtub characteristics of the two loaf agelums subjected to frequency analysis, two frequencies with the strongest signals at the same time are determined, and these are input to the calculation means.

On the other hand, the depths of the two receivers are measured using a depth gauge for measuring the depth of the receiver, and the two obtained depths are input to the calculation means.

Based on the input data, the calculation means calculates the depth of the submersible and the horizontal distance from the submersible to the wave receiver, and outputs the results.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 and 2. Here, the same reference numerals are used for the same constituent members as in the conventional example described above.

In the embodiment shown in FIG. 1, two receivers are arranged at the same location but at different depths to receive the direct wave sent from the transmitter 10 and the reflected wave at the sea surface. IA,I
B, depth gauges 2A and 2B that measure the depth of these two receivers IA and IB, and frequency analysis of the received signals obtained by each receiver IA and 1B to determine the phase of the direct wave and reflected wave. The signal processing units 3A, 3B calculate the two frequencies such that the deviation of the two frequencies is half a wavelength, and the depth of the receivers IA, IB obtained by the depth gauges 2A, 2B, and the signal processing units 3A, 3B obtain the depths of the receivers IA, IB obtained by the depth gauges 2A, 2B. The depth of the transmitter 10 and the receiver IA from the transmitter 10 are determined using each frequency.

It is equipped with a computer 100 as a calculation means for calculating the horizontal path ML to IB.

Here, the computer 100 is a depth meter 2A.

It is equipped with an input section 101 for inputting the depths of the receivers IA and IB obtained by 2B and each frequency obtained by the signal processing sections 3A and 3B, and a transmitter 10 based on these input data. It consists of a calculation section 102 that calculates the depth of the submersible and the horizontal path jilL from the transmitter 10 to the receivers IA and IB, and an output section 103 that outputs the calculation results.

Next, the calculation unit 102 will be explained in detail.

Figure 2 shows the path through which the sound waves emitted from the transmitter 10 installed on the submersible propagate to the receivers IA and IB. Waves 11A, IIB and reflected waves 12 reflected and transmitted from the sea surface
A, 12B is the first receiver IA installed at depth A1
and a second receiver, IB, installed at depth At. When the receivers IA and IB receive the direct waves 11A and IIB and the reflected waves 12A and 12B in phase, the intensity of the frequency increases. That is, the intensity increases at frequencies where the difference in distance between the paths of the direct waves 11A and LIB and the paths of the reflected waves 12A and 12B is half a wavelength. Expressing this in the formula: 1 (r” + (AIZ)”) −I (r” + (A-Z)”) = c/(2・f)
・・・・・・(1) Solving this for r, L=, /” [4・(4・＾”−(c/2・f)”)
・Z”-(4・A”-(c/2・f)”) ・(c
/2・f)”] /2・K・・・・・・(2)

On the other hand, the first and second signals obtained by the signal processing units 3A and 3B
The frequencies for the receivers IA and IB are respectively fl and f3. For formula (2), (AI, [1)
Since the horizontal distance under the conditions of and (At, f z ) is equal, the depth Z of the submersible is as follows.

Therefore, in equation (3), the first and second receivers IA, IB
Using the depth Z of the submersible obtained by substituting the depths AH, A2 and the frequencies f, , f, the horizontal distance can be obtained from equation (2).

Next, the operation will be explained.

A wave transmitter 10 mounted on a submersible radiates a sound wave with a wide band frequency. Two receivers IA and IB located at the same location at different depths receive the sound waves emitted from the transmitter 10. Each receiver LA, IB has direct waves 11A, IIB that directly reach the receivers IA, IB from the transmitter 10, and reflected waves 12A that are reflected from the sea surface and reach the receivers IA, IB.
, 12B are received and transmitted to the signal processing units 3A and 3B.

The signal processing units 3A and 3B generate direct waves 11A based on the signals transmitted from the wave receivers IA and IB.

11B and the reflected waves 12A and 12B are received in the same phase, the frequency is detected. Two sets of direct waves 11A.

11B and reflected waves 12A and 12B, and input these to the input section 101 of the computer 100.

On the other hand, the depths of the two receivers IA and IB are measured by the depth meters 2A and 2B for measuring the depths of the receivers IA and IB, and the two obtained depths are similarly input to the input section 101. input.

Based on the input data, the calculation unit 102 calculates the transmitter 1
Depth of the submersible carrying 0 and receiver IA from the submersible
, calculate the horizontal distance to IB. This result is transmitted to the output section 103, and the output section 103 outputs the result.

[Effects of the Invention] As explained above, in the present invention, two transmitters are placed at the same location but at different depths to receive the direct waves sent from the transmitter and the reflected waves at the sea surface. Equipped with a receiver and a depth meter that measures the depth of these two receivers, frequency analysis is performed based on the data obtained from the two receivers to determine the phase of the direct wave and reflected wave. Find two frequencies whose deviation is half a wavelength. On the other hand, the depths of the two receivers are determined by the depth meter, and based on these data, the calculating means calculates the depth of the submersible and the horizontal distance from the receiver. Therefore, since the accurate depth of the submersible can be obtained, it is possible to provide an unprecedented and excellent passive sonar device that can accurately measure the horizontal distance between the submersible and the wave receiver.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the propagation path of sound waves in the embodiment shown in FIG. 1, and FIG. 3 is a block diagram showing a conventional example. IA, IB...Receiver, 2A, 2B...
・Depth meter, 3'A, 3B...Signal processing section, 1
00...Computer as a calculation means.

Claims (1)

[Claims] (1) Two receivers placed at the same location but at different depths to receive the direct waves sent from the transmitter and the reflected waves at the sea surface, and these two receivers. A depth meter that measures the depth of the vessel and frequency analysis of the received signals obtained by each of the receivers to determine two frequencies at which the phase shift between the direct wave and the reflected wave is half a wavelength. A signal processing section calculates the depth of the transmitter and the horizontal distance from the transmitter to the receiver using the depth of the receiver obtained by the depth meter and each frequency obtained by the signal processing section. A passive sonar device comprising calculation means for calculating.