RU2039367C1 - Method of classification of moored mine provided with sonar equipment - Google Patents

Abstract

FIELD: underwater acoustics. SUBSTANCE: for increase of authenticity of moored mine in anechoic shell broadband acoustic signal is emitted, reflected signal is received and decision on detection of moored mine is made in compliance with increase of length of reflected signal of time constant of electroacoustic converter of given of moored mine. EFFECT: improved authenticity of detection of small-sized and poorly reflecting targets. 1 dwg

Description

 The invention relates to hydroacoustics for the detection of small and slightly reflective targets.

 A known method for classifying an anchor mine (NM) by comparing its target strength with the predicted target strength.

 This method does not provide detection of NM in anechoic execution of the body.

 The closest technical solution is a method for classifying an anchor bus, based on comparing the increase in the duration of the echo signal compared to the emitted one.

 This technical solution also does not allow the classification of NM in anechoic execution of the body.

 The inventive increase the reliability of the classification of NM in anechoic execution.

 This goal is achieved by supplementing the prototype method by comparing the measured values of the duration of the echo signals with a predicted value determined by the time constant of the electro-acoustic transducer of hydro-acoustic equipment of this type of mine, while the classification of the mine is refined to the type that is equipped with hydro-acoustic equipment designed to operate at a frequency at which a maximum increase in duration was noted.

It is known that an electro-acoustic transducer (EAP) can be represented in the form of an equivalent circuit, on the electric side of which the main components are the resistance R _o and the capacitance C _{o of the} transducer. For this purpose, after charging the capacitor (from the acoustic energy of the pulse-signal incident on the EAP and converted into electrical energy), a discharge occurs over time calculated by the formula τ = R _{i ˙} C _o .

или Д

13,65 м что значительно больше диаметра ЯМ, равного 0,533 м. Тангенс потерь (ТП) для параметрических ЭАП, как правило, имеет значение от 0,004 до 0,04. Примером для данного типа ЯМ ТП= 0,009, тогда из формулы ТП=1/2 π f ˙ R_o ˙ C_o получим R_o ˙ C_o=1/TПx x2π f, так как для частоты гидроакустической аппаратуры ЯМ f=10 кГц, ТП=0,009, получим
τ=R_o·C_o=1/0,009·2·3,14·10⁴

18,2 мс
Таким образом, ЯМ в звукопрозрачном исполнении корпуса тем не менее обнаруживается по эхо-сигналу от ее ЭАП. Следует учитывать то, что излучатели (ЭАП) ЯМ являются, как правило, узкополосными и даже у гидрофона есть резонансный пик частотной характеристики. Значение рабочей частоты позволяет точнее и достовернее классифицировать ЯМ. Сравнение с прототипом и другими техническими решениями позволяет сделать вывод о соответствии критериям "Новизна". "Неочевидность" и "Изобретательский уровень".For calculations, we use a numerical example, let
R _o 15.8 ˙ 10 ⁶ Ohms; C _o = 1150 ˙ 10 ^-12 F, then τ R ˙ C _o 15.8 ˙ 10 ⁶ ˙ 1150 ˙ 10 ^-12 18.2 ms, which is equivalent to the physical size of the target, determined by the formula
τ

or D

13.65 m, which is significantly larger than the diameter of the NM equal to 0.533 m. The loss tangent (TP) for parametric EAPs, as a rule, has a value from 0.004 to 0.04. An example for this type of NM is TP = 0.009, then from the formula TP = 1/2 π f ˙ R _o им C _o we get R _o ˙ C _o = 1 / TPx x2π f, since for the frequency of sonar equipment NM f = 10 kHz, TP = 0.009, we get
τ = R _o · C _o = 1 / 0.009 · 2 · 3.14 · 10 ⁴

18.2 ms
Thus, the NM in the translucent design of the body is nevertheless detected by the echo signal from its EAP. It should be borne in mind that NM emitters (EAPs) are, as a rule, narrow-band and even the hydrophone has a resonant peak in the frequency response. The value of the operating frequency allows more accurate and reliable classification of NM. Comparison with the prototype and other technical solutions allows us to conclude that the criteria of "Novelty". "Non-obviousness" and "Inventive step".

 At the same time, new features in combination with the features of the prototype provided a new quality, increased the reliability of the classification of NM of this type, performed in an anechoic design of the body.

 The drawing shows a block diagram of a device that implements the method, where it is indicated: 1-generator, 2 emitter, 3 receiver, 4.1-4.N comb of narrow-band filters of N-spatial channels; 5.1.1-5.1.M scheme for measuring the amplitude and increasing the duration of the echo signals at the output of M-narrow-band filters; 6 multi-pen recorder in coordinates: range, duration and amplitude of the echo signals in the M-sections of the studied frequency range and the N-spatial channels of the studied volume, 7 dimensional ruler.

 The operation of the generator and the sweep of the multi-pen recorder are synchronized.

 The method is as follows.

The generator 1 generates a broadband signal and through the emitter 2 locates the investigated volume. The echo signals received by receiver 3 arrive in parallel to the combs of narrow-band i filters i = 1,2, N 4 and spatial channels consisting of j = 1,2. M narrow-band filters. The outputs of the combs are connected through the corresponding measurement schemes i, j of amplitude and duration 5 to the corresponding inputs of the multi-pen recorder 6. The figure shows that in the first spatial channel at a frequency f _{3 there is} a contrast increase in the duration of the echo signal corresponding to the second range element, while the duration measured by the operator with a measuring gauge 7, compared with the predicted value of τ calculated for the corresponding type of NM and given in the table or calculated in a separate block. The correspondence of the measured magnitude of the change in the duration of the echo signal to the predicted value τ, as well as the determination of the frequency f _{3 of the} operation of the hydroacoustic equipment increase the reliability of the classification of this type of NM.

 Elements of a device that implements the method are made on the basis of typical products described in the literature.

The proposed method allows to classify NM with high reliability due to the receipt of additional information:
1) the correspondence of the measured increase in the duration of the echo signal to the predicted value;
2) determination of hydroacoustic equipment (GAA) of NM based on the frequency at which it is intended to operate. This allows one to more reliably classify NMs in an anechoic design of the body, as well as more effectively suppress its GAA, knowing the frequency at which it is intended to operate.

Claims (1)

 A METHOD FOR CLASSIFICATION OF AN ANCHOR MINES EQUIPPED WITH HYDROACOUSTIC EQUIPMENT, based on the emission of an acoustic broadband signal, registration by the receiver of echo signals for all elements of the range of the investigated volume, characterized in that they measure the increase in the duration of the echo signal for all sections of the studied frequency range and make a decision about the specific classification type of anchor mine, equipped with hydroacoustic equipment, designed to operate at frequencies in which the maximum increase duration, but not less than an interval equal to the time constant of the electro-acoustic transducer.

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