RU2492497C1 - Method of determining torpedo parameters - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: in the method of determining parameters of a torpedo moving on a homing trajectory, involving receiving acoustic signals of the torpedo with a hydroacoustic antenna mounted on observer ship, converting the acoustic signal to an electric signal, pre-amplification and primary processing of the received signal, automatic angle tracking of the torpedo, classifying the received signal and determining motion parameters of the torpedo in a computer, includes further reception of probing radiation signals of the torpedo homing system, determining frequency of the probing signal, duration thereof, tracking period and level; classification results are used to determine parameters of the torpedo homing system - antenna area, level of reception acoustic interference; reflectivity of the observer ship is determined; propagation loss and threshold level of the probing signal P_settl are determined using a sonar equation applied to the torpedo homing system; the current signal level P_t is compared with the threshold signal level P_settl and the moment when the condition P_t≥P_settl is satisfied is defined as the moment of detection of the torpedo by the observer.

EFFECT: determining the moment of an observer detects the torpedo homing system, high efficiency of counteracting security of the observer.

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Description

The invention relates to sonar and can be used by an observer to assess the degree of threat from a torpedo.

The assessment of the degree of threat from the torpedo is carried out by the hydroacoustic station of the observer in the passive mode by the received sounding signals of the active homing system (SSH) of the torpedo. The threat to the observer from the side of the torpedo comes from the moment when the torpedo homing torch detects it.

Traditionally, systems for passive detection of signals from working sonars solve the problem of detecting the fact of the operation of the torpedo hitch, determine the parameters of the probing signals and the direction to the torpedo. The choice of the detection threshold of the probe signal is based on the need to make a binary decision "signal is" or "signal is not" [1].

Known methods for passively determining the parameters of a marine object, including torpedoes, by its sounding signals, implemented by hydroacoustic complexes (SAC) and stations (GAS), for example, “Hydroacoustic complex MGK-400EM” [2]. The method for determining the parameters of a torpedo implemented by this sonar system from its sounding signals provides for the determination of the type of torpedo, the parameters of its SSN and direction to the torpedo. The operator of the hydroacoustic signal detection mode displays data on the frequency and duration of the sounding signal, the signal repetition period, signal level and direction to the torpedo. The disadvantage of the implemented method of processing information is the inability of the observer to make an objective decision - whether he was detected by the homing system of the torpedo and, thereby, take timely protective measures, for example, use electronic warfare (EW), use self-defense weapons, and perform active maneuvering to evade.

There is also known a method for passively determining torpedo parameters by a hydro-acoustic station for analyzing and classifying signals by sounding signals of a torpedo homing system (CCH), implemented in the hydro-acoustic station AN / WLY-1 [3]. The method for determining torpedo parameters implemented in this GAS provides for the formation of a multi-beam directivity pattern, the processing of information in the computer in automatic mode, provides for detection, classification of torpedoes, determination of their coordinates, bringing the observer and his self-defense systems into combat condition. AN / WLY-1 controls the space around the observer through 360 ° using receiving antenna devices of the HAS. The sonar transmitter AN / WLY-1 is capable of:

- notify the observer about the approach of a torpedo;

- manage the installation of electronic warfare devices to suppress the torpedo fire;

- manage the launch of self-defense weapons;

- determine the parameters of the movement of the torpedo and predict the effectiveness of the torpedo protection of the observer;

The disadvantage of this GAS is the inability of the observer to timely detect the fact of his torpedo detection, and thus, there is the likelihood of the observer using the EW and self-defense weapons prematurely, that is, if the torpedo missile launcher did not detect the observer, and he, in turn, used the self-defense means prematurely (EW, weapon and other), it thereby reveals itself and creates tactical advantages for the opposite side. On the other hand, if the observer detected a torpedo by the torpedo hitch, and he, in turn, delays the use of self-defense means, then there are also negative consequences for self-defense, when self-defense means are ineffective.

Thus, the discovery of a torpedo by the sonar station AN / WLY-1 or another ASG, HAK, does not yet indicate that the torpedo has detected an observer and is pointing at it.

An observer who detects torpedoes from the passive ASG signals tries to prevent premature detection of his location by any of his actions, since the ability to evade a torpedo is very difficult due to the fact that the speed of the torpedo is usually greater than the speed of the observer.

The closest set of features to the proposed method is a method for passively determining the parameters of a maneuvering object [8,], which provides the reception of acoustic noise signals of a maneuvering object moving along a homing path, a hydroacoustic antenna, converting an acoustic signal into an electric signal, preliminary amplification and signal conversion, automatic tracking the maneuvering object by angle, its classification and determining the distance to the object in the calculation e.

A torpedo is a special case of the implementation of a maneuvering object, the trajectory of which is determined by the operation of its SSN operating in passive and active guidance modes [11]. Further consideration will be carried out in relation to a torpedo equipped with an active homing system.

The disadvantage of the above method - the prototype, as well as the above analogues, is the impossibility, according to the results of the classification and determination of the coordinates and parameters of the torpedo movement, of determining the moment the observer was detected by the homing system, which does not allow the observer to evade the object in a timely manner and proceed with protective actions in a timely manner. Premature protection actions may unmask the observer, and delay may result in damage.

The objective of the invention is to develop a method for determining the parameters of a torpedo, providing timely warning to the observer about his detection by the homing system of a torpedo.

The technical result from the use of the invention is the determination of an important parameter of the torpedo - the moment the observer was detected by the torpedo homing system, which improves the efficiency of the torpedo protection of the observer.

To solve the problem, a method for determining the parameters of a torpedo moving along a homing path, including receiving acoustic signals from a torpedo with a hydroacoustic antenna mounted on an observing vessel, converting an acoustic signal into an electric signal, preliminary amplification and primary processing of the received signal, automatic tracking of the torpedo by angle, classification of the received signal and determination of the parameters of the movement of the torpedo in the computer, new features have been introduced, namely: of the radiation signals of the CLS of a torpedo, determine the frequency of the probing signal, its duration, repetition period and level, according to the classification results determine the parameters of the homing system of the torpedo - the area of the CLS emitting antenna, the level of acoustic noise reception, determine the reflectivity of the observing vessel using the sonar equation as applied to CCH torpedoes, determine propagation loss and threshold value of the level of the probing signal P _calc , compare the level of the current signal P _t with a threshold value of the level of the probing signal and the moment the condition P _t ≥P is fulfilled, the _calculation is determined as the moment of detection by a torpedo observer.

The method for determining the parameters of a torpedo is based on the passive detection by a sonar station of an observer of probing signals CCH, determining the class of a torpedo and measuring the parameters of the probing signals - frequency F ₀ , duration τ ₀ , pulse repetition period T, current signal level P _t and determine its reflective abilities R (ψ ₀ ) as a function of the heading angle to the marine object ψ ₀ , determination of the torpedo by the GAS calculator of the observer of the observer, and calculation of the threshold signal level of the SSN P from these data _calculation , at which the observer is detected by the homing system with a given probability and a continuous check of the condition P _t ≥Р _calculation , upon reaching which the warning signal about the observer detection is triggered.

The invention is illustrated in figure 1, which shows a device that implements a method for determining the parameters of a torpedo and figure 2, which shows the dependence of the noise level flow around the body for different frequencies, borrowed from [6].

The proposed method is implemented by the device (Fig. 1), including a receiving hydroacoustic antenna 1, block 2 of preliminary and primary processing, block 3 of automatic tracking of the target for measuring the heading angle to the torpedo ψ ₀ , block 4 for measuring signal parameters F ₀ , τ, T, P _t , block 5 classification definition of a class of torpedoes and calculator 6.

Calculator 6 is a hardware-software unit of the digital computing complex of the hydroacoustic observer station, connected to the outputs of blocks 3, 4, and 5. The algorithm is implemented in the computer programmatically.

Blocks 2, 3, 4, and 5 are known from [8].

The proposed method is implemented as follows: a mixture of direct sounding signal and interference from the output of the hydroacoustic antenna 1 is supplied to block 2 for preliminary and primary signal processing, which emits a sounding signal that is sent to block 3 for automatically tracking the target by an angle, which is connected to calculator 6 and block 4 measuring signal parameters according to the algorithms described, for example, in [9]. The output of block 4 is connected to the input of the classification block 5, which determines the class of the torpedo (universal torpedo or small-sized) and issues the parameters of this CLP to the calculator 6.

When classifying such a target as a torpedo, we can assume that the diameter of the torpedo determines the allowable size of the antenna. So for a universal torpedo with a diameter of 533 mm, having an appropriate carrier frequency of the SSN, the diameter of the antenna, with an acceptable error value, is 500 mm and this parameter is used to calculate the area of the antenna. For a small torpedo with a diameter of 324 mm, with a probe signal frequency characteristic of it, the diameter of the CCH antenna is 300 mm and the same is used to calculate the area of the antenna.

The calculator 6 implements an algorithm for determining the calculation of the threshold level of the signal and comparing it with the current level in accordance with the algorithm presented in figure 1. From block 3 of automatic tracking of the target, the heading angle ψ ₀ data is sent to the computer in calculator 6, where the intrinsic reflectivity of the observer vessel is calculated (when approximating the ship’s hull with a cylinder), which is calculated by the formula [6] -

$$R\left({\psi }_0\right)=\frac{\alpha }{2\lambda }{L}^2{\left(\frac{\sin \beta }{\beta }\right)}^2{\cos }^2{\psi }_0\left(\text{one}\right)$$

where: α is the diameter of the cylinder;

L is the length of the cylinder;

β = kLsinψ ₀ ;

λ is the wavelength;

ψ ₀ - heading angle to the torpedo;

The calculator 6 receives data on the values of F ₀ , t, T, P _t from block 4, the values of the interference level R _{NNP of the} receiving path of the CCN torpedoes from block 5, determined from _figure 2 [6] and the area of the emitting antenna S _torus , the size of which defined by the class of torpedoes (universal or small), on the basis of which according to the algorithm shown in figure 1, determine the value of the propagation loss by the formula [5], -

$${10}^6{r}_{\mathrm{to}m}^2{10}^{0.1\beta r_{\mathrm{to}m}}=\frac{3.45{\text{10}}^{\text{2}}\sqrt{w_{\mathrm{at}d}S\gamma }\frac{R{\left({\psi }_0\right)}^2}{\mathrm{four}}}{z\sqrt{\frac{P_{nnP}^2\Delta ƒ}{\gamma F_0^2}}{q}_{P\mathrm{about}R}}\left(\text{2}\right)$$

where: w _beats is the specific radiation power taken from a unit surface of the antenna W / cm ² (in practice, w _beats = 2 W / cm ² );

r is the distance between the object and the observer;

z - unaccounted losses during processing (usually take z = 2);

S _mop = πd ² is the surface area of the emitting torpedo SSN antenna, determined by belonging to a certain class;

d is the diameter of the antenna;

γ is the concentration coefficient of the torpedo antenna;

$$\gamma =\mathrm{four}\pi S_{top}{\left(F_0\right)}^2/c^2\left(\text{3}\right)$$

C is the speed of sound in sea water;

Δf = 1 / τ ₀ is the passband of the receiving path of the HS of the marine object;

q _then - the required threshold signal-to-noise ratio at which the specified probabilities of the correct detection of P _by and false alarm P _lt [5] are provided, equal to -

$$q_{P\mathrm{about}R}=\left(\frac{In{N}_{lt}/M}{In{N}_{P\mathrm{about}}}-\mathrm{one}\right)\left(\text{four}\right)$$

where: M = m _Θ m _t m _in - the number of elements of the resolution of the receiving path CCH

m _Θ = Θ / (2arcsin0.44λ / d) is the number of directivity characteristics in the horizontal region [10];

Θ = 300 ° the estimated sector of the SSN survey, corresponding to modern models of foreign torpedoes;

m _t = T / τ ₀ is the number of resolution elements in range,

where: T is the period following the probing signals of the SSN torpedoes;

m _in = 3 - the number of directivity characteristics in the vertical plane;

This value of m _is taken as a reasonable assumption, because changing it up or down affects the parameter q _then insignificantly.

N _lt = 0.1 - the probability of false alarm for the detection cycle;

N _by = 0.9 is the probability of correct detection;

N _lt , N _by - are taken equal to the forecast parameters of most search engines;

Then calculate the level of radiated pressure of the SSN torpedoes according to the formula [5] -

$$P_0=3.46{\text{10}}^{\text{2}}\sqrt{w_{\mathrm{at}d}St\mathrm{about}R\gamma }\left(\text{5}\right)$$

From the calculated values of the propagation loss and the values of the radiation level P ₀ SSN, torpedoes determine threshold values of the signal level:

$$P_{R\mathrm{but}\mathrm{from}h}=\frac{P_0}{{10}^6{r}_{\mathrm{to}m}^2{10}^{0.1\beta r_{\mathrm{to}m}}}\left(\text{6}\right)$$

which is then compared with the current value of the level P _t, and if the condition P _t ≥P _calculation is fulfilled, the moment of observer detection by a torpedo is determined.

This allows us to assume that the claimed technical result has been achieved and provided an increase in the effectiveness of anti-torpedo protection.

Information sources

1. I.M. Shooters. Generalized signal detection model. Proceedings of the second all-Union school of the workshop on statistical hydroacoustics. Novosibirsk 1971, p.172-191.

2. I.V. Soloviev, G.N. Korolkov et al. Marine radio electronics. St. Petersburg., 2003, S. 96-99.

3. N. Friedman. World Naval Weapons Systems Update, US Naval Institute, Annapolis, 1998, pp. 62-68.

4. V.A. Zaraysky, A.M. Tyurin. The theory of sonar. L., 1975 p. 422.

5. Yu.S. Kobyakov, N.N. Kudryavtsev, V.I. Tymoshenko. Design of sonar fishing equipment. L., 1986, p. 69, 75, 76.

6. R.J. Urik. Basics of sonar. L., 1978, p.307, 378.

7. A.P. Evtutov, V.B. Mitko. Examples of engineering calculations in sonar. L., 1981, p. 86.

8. RF patent No. 2196341 mcl G01S 3/80 11/01/2001 - A method for determining the motion parameters of a maneuvering object.

9. Ya.D. Shirman. Theoretical foundations of radar. M., 1970, p. 185-194.

10. A.P. Evtutov, V.B. Mitko. Examples of engineering calculations in sonar. L., 1981, pp. 14-22.

11. V.A. Horsetail. Submarine tactics. M., 1989, p. 124-125.

Claims (1)

A method for determining the parameters of a torpedo moving along a homing path, including receiving acoustic signals of a torpedo with a hydroacoustic antenna mounted on an observing vessel, converting an acoustic signal into an electric signal, preliminary amplification and primary processing of the received signal, automatic tracking of the torpedo by angle, classification of the received signal and determination of parameters torpedo movement in the computer, characterized in that they receive sounding signals of the radiation of the homing system of the torpedoes, determines the frequency of the probing signal, its duration, repetition period and level, according to the classification results determine the parameters of the torpedo - the area of the emitting antenna of the CLP, the level of acoustic noise to the reception, determine the reflectivity of the observing vessel using the sonar equation in relation to the CLP of the torpedo determine the propagation loss and probing threshold signal level P _calc, performed comparing the level of the current signal P _t with the threshold signal level P _calc and momen the condition P _t ≥P _pacch defined as the time of detecting the torpedo observer.

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