RU2492503C1 - Target class recognition method and device for realising said method - Google Patents

Abstract

FIELD: radio engineering, communication.SUBSTANCE: method of recognising the class of a target involves radiating electromagnetic energy towards the target; receiving signals reflected from the target and recognising the target; performing narrow-band filtering of the Doppler frequency component of the spectrum of the reflected signal; determining the target approach velocity band ?V, which is included in the band-pass of the a Doppler frequency filter ?Fusing the expression ?V=?F?/2, where ? is the radiation wavelength; determining the Doppler frequency band ?Foccupied by the signal reflected from the target; determining target velocity band ?Foccupied by the signal reflected from the target using the expression ?V=?F?/2; determining the ratio ?=?V/?V, wherein if ??0.01, the target is considered a point target on velocity, and if ??0.01, the target is considered an extended target on velocity, characterised by that the extended target is selected according to the expression: ?=?V/?V, at a given distance from the target, wherein if ???, the target is considered small, if ???the target is considered medium and if ???the target is considered large, wherein said inequalities uniquely determine the class of the target at the following valuesThe device for recognising the class of a target further includes a channel for selecting extended targets, a "small target" indicator, a "medium target" indicator and a "large target" indicator.EFFECT: high information value owing to recognition of the class of a target - small, medium and large.2 cl, 1 dwg

Description

The invention relates to systems for detecting objects by reflection of radio waves from its surface and can be used in radar to recognize the target class.

A known recognition method, which consists in the emission towards the target of electromagnetic energy, the reception of electromagnetic energy reflected from the target, signal processing, target recognition by the received image of geometric dimensions and configuration [1].

A device for radar target recognition, containing an antenna, transmitter, receiver, antenna switch and recognition channel, the transmitter contains a modulator, microwave generator and a first key, where the modulator output is connected to the first input of the first key and the first output of the transmitter, the output of the microwave generator is connected to the second input of the first key and the second output of the transmitter, the output of the first key is the third output of the transmitter and is connected to the first input of the antenna switch, the second input of which is connected to antenna, and the output with the input of the receiver; the recognition channel contains a delay line, a second key, a mixer, a low-pass filter and a target image reproducing device, the input of the delay line being the first input of the recognition channel and connected to the first output of the transmitter, the second input of the mixer being the second input of the recognition channel and connected to the second the output of the transmitter, the second input of the second key is the third input of the recognition channel and is connected to the second output of the receiver, the first output of the transmitter and the output of the receiver are ineny with inputs circular indicator radar review [2].

The disadvantage of the data of the method and device is the low information content due to the lack of recognition of a speed-extended target. In practice, the vast majority of real objects belong to the class of complex radar targets.

Errors in the measurement of coordinate parameters caused by the noise of the target begin to occur when the physical dimensions of the target exceed 0.01 values of the resolution element in any coordinate (Radar characteristics of aircraft [3].

Closest to the invention is a method for recognizing an extended target, which consists in emitting electromagnetic energy towards the target, receiving signals reflected from the target and recognizing the target, performing narrow-band filtering of the Doppler frequency component of the reflected signal spectrum, determining the proximity speed band with the target ΔV included in the passband Doppler frequency filter ΔF _D from the expression ΔV = ΔF _D · λ / 2, where λ is the radiation wavelength, determining the Doppler frequency band ΔF _Dts by the occupied signal reflected from the target, determining the target’s speed range ΔV _c by the occupied signal reflected from the target from the expression ΔV _c = ΔF _Dc · λ / 2, determining the ratio β = ΔV _c / ΔV in this case, if β <0.01, the decision on speed of the target, and in the case β> 0.01, a decision is made on the target extended in speed [4].

The recognition device for an extended target, contains a transmitter, an antenna switch, an antenna and a receiver, a recognition channel, while the first, second and third outputs of the transmitter are connected respectively to the first input of the antenna switch, the second and third inputs of the recognition channel, the first input of which is connected to the output of the receiver, the second input is the output of the antenna switch is connected to the antenna, and the output is with the input of the receiver, the first output of the transmitter and the output of the receiver are connected to the inputs of the indicator station, and the transmitter contains a modulator, a microwave generator and a first key, and the output of the modulator is connected to the first input of the first key, the second input of which is connected to the output of the microwave generator, the outputs of the modulator, microwave generator and the first key are respectively the first, second and the third outputs of the transmitter, and the recognition channel contains a series-connected delay line, a second key, a mixer, a Doppler frequency filter, a signal duration meter, a calculator and a threshold device, When this first, second and third inputs of detection channels are respectively inputs of the mixer, a delay line, a second input of the second switch, the first and second outputs of the threshold devices are first and second outputs detection channel [4].

The disadvantage of the data of the method and device is the inability to recognize an extended target by the class of the target: small, medium and large target.

An object of the invention is to expand the information content by providing the ability to recognize an extended target by the target class: small, medium and large target.

$${\beta }_2=\frac{\Delta V_{ц}}{\Delta V}=\mathrm{0,25,}$$

$${\beta }_3=\frac{\Delta V_{ц}}{\Delta V}=\mathrm{0,40.}$$

The technical problem of the invention is achieved by the fact that in the method of recognizing an extended target, which consists in emitting electromagnetic energy towards the target, receiving signals reflected from the target and recognizing the target, performing narrow-band filtering of the Doppler frequency component of the reflected signal spectrum, determining the approximation velocity band with the target ΔV, which is included into the passband of the Doppler frequency filter ΔF _D from the expression ΔV = ΔF _D · λ / 2, where λ is the radiation wavelength, determining the Doppler frequency band ΔF _Dts occupied by the signal, neg from the target, determining the target’s speed range ΔV _c occupied by the signal reflected from the target from the expression ΔV _c = ΔF _Dc · λ / 2, determining the ratio β = ΔV _c / ΔV, while in the case β <0.01 they make a decision about a point-wise target speed, and if β> 0.01, they make a decision about an extended, speed-wise target, additionally select an extended target at a given distance from the target according to the class of the target in accordance with the expression β = ΔV _c / ΔV, decide that purpose small if β≥β _1, decide that the target average in cases e if β≥β _2, decide that the goal of most, if β≥β _3, the proposed inequality uniquely identify a class goal for following values: $${\beta }_{\mathrm{one}}=\frac{\Delta V_c}{\Delta V}=0.05$$

$${\beta }_2=\frac{\Delta V_c}{\Delta V}=\mathrm{0.25,}$$

$${\beta }_3=\frac{\Delta V_c}{\Delta V}=\mathrm{0.40.}$$

$${\beta }_2=\frac{\Delta V_{ц}}{\Delta V}=\mathrm{0,25,}$$

$${\beta }_3=\frac{\Delta V_{ц}}{\Delta V}=\mathrm{0,40,}$$

выход второго порогового устройства соединен с первым входом второго элемента И, второй и третий входы которого соединены с выходами третьего и четвертого элементов НЕ, выход третьего порогового устройства соединен одновременно со входом третьего элемента НЕ и первым входом третьего элемента И, второй вход которого соединен с выходом четвертого элемента НЕ, выход четвертого порогового устройства соединен со входом четвертого элемента НЕ, выходы второго, третьего элементов И и четвертого порогового устройства являются соответственно первым, вторым и третьим выходами канала селекции протяженных целей.The claimed method is implemented in an extended target recognition device containing a transmitter, an antenna switch, an antenna and a receiver, a recognition channel, while the first, second and third outputs of the transmitter are connected respectively to the first input of the antenna switch, the second and third inputs of the recognition channel, the first input of which is connected with the output of the receiver, the second input-output of the antenna switch is connected to the antenna, and the output is with the input of the receiver, the second output of the transmitter and the output of the receiver are connected to the indi inputs the radar station’s all-round visor, and the transmitter contains a modulator, a microwave generator and a key, the modulator output connected to the first key input, the second input of which connected to the microwave generator output, the key, modulator and microwave generator outputs are respectively the first, the second and third outputs of the transmitter, and the recognition channel contains a delay line, a key, a mixer, a Doppler frequency filter, a signal duration meter, a calculator, and a threshold device in, while the first, second and third inputs of the recognition channel are, respectively, the second key input, inputs of the delay line and mixer, and the first and second outputs of the threshold device are the first and second outputs of the recognition channel, an additional selection channel for extended targets is added, the indicator is small, the indicator is an average target, the indicator is a large target, and the first, second and third inputs of the selection channel for extended targets are connected respectively to the first output of the transmitter, the output of the receiver and the second output of the channel recognition, the first, second and third outputs of the selection channel for extended targets, respectively connected to the inputs of the indicators small target, middle target and large target, the selection channel for extended targets contains an OR element, a differentiating circuit, a shift register, the first, second, third and fourth elements are NOT , a signal generator, first, second and third elements AND, a counter, first, second, third and fourth threshold devices, first, second and third keys, a signal generator, with the first, second and third inputs of the selection channel heavy targets are respectively the first and second inputs of the OR element, the second inputs of the second, third and fourth threshold devices, the input of the differentiating circuit is connected to the first output of the transmitter, and the output is connected to the second inputs of the shift register and counter, the output of the OR element is connected to the first input of the shift register , the third input of which is connected to the output of the pulse generator, the first and second outputs of the shift register are connected through the first element NOT and directly with the first and second inputs of the first element And, the third input of which is connected to the output of the pulse generator, the output of the first element And, through the first input of the counter, is connected to the second input of the first threshold device, the second input of which is connected to the first output of the signal setter, the output of the first threshold device through the second element is NOT connected to the second the inputs of the first, second and third keys, the first inputs of which are connected to the second, third and fourth outputs of the signal setter, and the outputs of these keys are connected respectively to the first inputs of the second, third and the fourth threshold devices, the threshold value of the signal for the first threshold device is set at the first output of the master depending on the specified range to the target, the threshold values of the signals of the second, third and fourth threshold devices are set at the second, third and fourth outputs of the signal master, while the value of the threshold values of the signals β ₁ ; β ₂ ; β ₃ ; are determined in accordance with the following values: $${\beta }_{\mathrm{one}}=\frac{\Delta V_c}{\Delta V}=0.05$$

$${\beta }_2=\frac{\Delta V_c}{\Delta V}=\mathrm{0.25,}$$

$${\beta }_3=\frac{\Delta V_c}{\Delta V}=\mathrm{0.40,}$$

the output of the second threshold device is connected to the first input of the second AND element, the second and third inputs of which are connected to the outputs of the third and fourth elements NOT, the output of the third threshold device is connected simultaneously with the input of the third element NOT and the first input of the third AND element, the second input of which is connected to the output the fourth element is NOT, the output of the fourth threshold device is connected to the input of the fourth element is NOT, the outputs of the second, third elements And and the fourth threshold device are respectively ervym, second and third elongated output channel selection purposes.

New features that have significant differences in the method is the following set of actions.

1. Select an extended target at a given distance from the target in accordance with the expression: β = ΔV _c / ΔV

2. Make a decision that the goal is small if β≥β ₁ .

3. Decide that the goal is average in the case of β≥β ₂ .

4. Decide that the goal is large in the case of β≥β ₃ .

New elements that have significant differences in the device are the additionally introduced extended target selection channel, the indicator is a small target, the indicator is an average target, and the indicator is a large target.

The drawing shows a functional diagram of a device for recognition of an extended target.

The target class recognition device comprises a transmitter 1, an antenna switch 2, an antenna 3, a receiver 4, a recognition channel 5, an extended target selection channel 6, an indicator 7 is a small target, an indicator 8 is an average target, and an indicator 9 is a large target.

The transmitter 1 contains a modulator 10, a microwave generator 11 and a key 12, while the output of the microwave generator 11 is connected to the second input of the key 12, the outputs 12 of the key, the modulator 10 and the microwave generator 11 are the first, second and third outputs of the transmitter 1, respectively.

The recognition channel 5 comprises a delay line 13, 14 key, mixer 15, a Doppler frequency filter 16, a duration meter 17, a calculator 18, and a threshold device 19 connected in series, the first, second, and third inputs of the recognition channel 5 being respectively the input of the delay line 13, the input of the key 14, the second input of the mixer 15, the first and second outputs of the threshold device 19, are respectively the first and second outputs of the recognition channel 5.

Channel 6 selection of extended targets contains an OR element 20, a differentiating circuit 21, a shift register 22, the first 23, the second 24, the third 25 and the fourth 26 elements are NOT, the signal generator 27, the first 28, the second 29 and the third 30 elements And, the counter 31, the first 32, second 33, third 34 and fourth 35 threshold devices, the first 36, second 37 and third 38 keys, a signal setter 39, while the first, second and third inputs of the extended target selection channel 6 are the first and second inputs of the OR element 20, the second inputs of the second 33, third 34 and fourth 35 threshold devices.

The first, second and third outputs of the transmitter 1 are connected respectively to the first input of the antenna switch 2 and the second and third inputs of the recognition channel 5, the second input-output of the antenna switch 2 is connected to the output-input of the antenna 3, the output of the antenna switch 2 is connected to the input of the receiver 4, the output of which is connected to the first input of the recognition channel 5 and simultaneously with the second input of the extended target selection channel 6, the first and third inputs of which are connected respectively to the first 1 output of the transmitter and to the second the output of the recognition channel 5, the first, second and third outputs of the extended target selection channel 6 are connected to the inputs of the indicator 7 small target, indicator 8 the middle target and indicator 9 large target, the input of the differentiating circuit 21 is connected to the first output of the transmitter 1, and the output is connected to the second the inputs of the shift register 22 and the counter 31, the output of the OR element 20 is connected to the first input of the shift register 22, the third input of which is connected to the output of the pulse generator 27, the first and second outputs of the shift register 22 are connected through the first 23 t NOT and directly, with the first and second inputs of the first 28 And element, the third input of which is connected to the output of the pulse generator 27, the output of the first 28 And element, through the first input of the counter 31, is connected to the second input of the first 32 threshold device, the second input of which is connected with the first output of the signal setter 38, the output of the first 32 threshold device is connected to the second inputs of the first 36, second 37 and third 38 keys, the first inputs of which are connected to the second, third and fourth outputs of the signal setter 39, and the outputs of these keys with connected to the first inputs of the second 33, third 34 and fourth 35 threshold devices, the output of the second 33 threshold device is connected to the first input of the second 29 AND elements, the second and third inputs of which are connected to the outputs of the second 24 and third 25 elements NOT, the output of the third 34 threshold device connected simultaneously with the input of the second 24 element NOT and the first input of the third 30 element AND, the second input of which is connected to the output of the third 25 element NOT, the output of the fourth 35 threshold device is connected to the input of the fourth 26 e ementa NOT outputs of second 29, third 30 and fourth AND gates 35 threshold devices are respectively first, second and third output channel 6 extended breeding purposes.

The threshold signal values for the first 32, second 33, third 34 and fourth 35 threshold devices of channel 6 for selecting an extended target are set based on the following considerations.

The threshold value of the signal for the first 32 threshold device is set at the first output of the setter 39 depending on the specified range to the target.

The values of the threshold values of the signals of the second 33, third 34 and fourth 35 threshold devices are set at the second, third and fourth outputs of the signal generator 39, while the threshold values of the signals β ₁ ; β ₂ ; β ₃ ; are determined in accordance with the following values:

$${\beta }_{\mathrm{one}}=\frac{\Delta V_c}{\Delta V}=0.05$$

$${\beta }_2=\frac{\Delta V_c}{\Delta V}=\mathrm{0.25,}$$

$${\beta }_3=\frac{\Delta V_c}{\Delta V}=\mathrm{0.40,}$$

where ΔV _c is the target speed bandwidth, ΔV is the approximation target speed bandwidth.

Determining the geometrical dimensions of targets requires a radar station with high resolution in range of less than 1 m (<1 m). The implementation of this resolution is possible either through the use of unmodulated pulse signals of very short duration or due to signals with intrapulse modulation. Unmodulated signals of very short duration (units - tens of nanoseconds) are sometimes called ultra-wideband signals (UWB). Multi-frequency radars with UWB provide resolution in units of centimeters and determine the radar characteristics of objects at a distance of units of kilometers [Astanin L.Yu., Kostylev A.A. Methods of theoretical and experimental non-stationary scattering and radiation of electromagnetic waves. - Foreign Radio Electronics, 1981, No. 9, p.3-37].

The specified range is acceptable for target recognition at the final section of the radar homing aircraft guided missiles. The bandwidth of the reflected signal depends on the class of the target: small target (5 m), medium target (25) m, large target (40) m. This fact is an informative sign for determining the class of the target at short distances to the target.

The device operates as follows.

The signal reflected from the moving target is fed to the input of antenna 3 and through the antenna switch 2, receiver 4 and second 10, the key is fed to the first input of mixer 11. The second input of mixer 11 receives a signal from the output of microwave generator 7, thus, at the output of mixer 11 signal at the Doppler frequency. This signal is transmitted through a filter 12 of Doppler frequencies to the input of the duration meter 13, the output of which is a signal proportional to the duration of the signal reflected from the target. This signal is fed to the input of the calculator 14, at the output of which a signal is generated proportional to β = ΔV / ΔV _c , which is fed to the input of the threshold device 15, where it is compared with a threshold of 0.01. When the threshold is exceeded, a “extended” signal is issued; in the opposite case, a “point” signal is issued. These signals are the output signals of the recognition channel 5.

Channel 6 selection of long targets is designed to determine the class of goals: small, medium and large target.

The first, second and third inputs of the selection channel for extended targets receive signals from the first output of the transmitter 1, the output of the receiver 4 and from the second output of the recognition channel 5, while the signals are received respectively at the first and second inputs of the OR element 20, the second inputs of the second 33, third 34 and fourth 35 threshold devices.

When the transmitter 1 is turned on, the signal from its first output goes to the input of the differentiating circuit 21, from the output of which the zeroing signal goes to the second inputs of the shift register 22 and counter 31.

From the output of the OR element 20, the signal is fed to the first input of the shift register 22, the third input of which receives a signal from the output of the pulse generator 27.

From the first and second output of the shift register 22, the signals are supplied through the first 23 element NOT and directly to the first and second inputs of the first 28 element And, the third input of which receives a signal from the output of the pulse generator 27.

From the output of the first 28 AND element, the signal corresponding to the range to the target enters through the first input of the counter 31, to the second input of the first 32 threshold device, the second input of which receives the signal from the first output of the signal setter 38.

At the moment of reaching the current range of the set value, the signal from the output of the first 32 threshold device is removed, while the output of the second 24 elements is NOT the signal goes to the second inputs of the first 36, second 37 and third 38 keys, the first inputs of which receive signals from the second, third and the fourth outputs of the setter 38 signals.

From the outputs of these keys, signals of various levels are supplied respectively to the first inputs of the second 33, third 34 and fourth 35 threshold devices.

Depending on the target class, in the case of β≥β ₁ , the second 33 threshold device is triggered and the signal is supplied to the first input of the second 29 AND elements, the second and third inputs of which receive signals from the output of the second 24 and third 25 NOT elements, thereby signal passing to the input of the indicator 7 of the small target.

If β≥β ₂ , the signal from the output of the third 34 threshold device is fed to the first input of the third 30 element AND, the second input of which receives the signal from the output of the third 25 element NOT, thereby ensuring the passage of the signal to the input of indicator 8 of the average target.

If the value β≥β ₃ , then the signal from the output of the fourth 35 threshold device is fed to the input of the indicator 9 is a big target.

INFORMATION SOURCES

1. US patent No. 3978480, CL. G01S 9/00, 1974

2. Nebabin V.G., Sergeev V.V. Methods and techniques of radar recognition. - M .: Radio and communications, 1984, p. 36.

3. M.E. Varganov, Yu.S. Zinoviev, L.Yu. Astanin et al. Ed. L.T. Tuchkova. Radar characteristics of aircraft. - M .: Radio and communications, 1985 .-- 236 p., Ill. p.17-18.

4. Vinokurov V.I., Vinokurov D.V., RF patent No. 2359285 dated 06/20/2009, IPC G01S / 53.

Claims (2)

1. A method for recognizing the target class, which consists in emitting electromagnetic energy toward the target, receiving signals reflected from the target and recognizing the target, performing narrow-band filtering of the Doppler frequency component of the reflected signal spectrum, determining the proximity velocity band with the target ΔV, which is included in the passband of the Doppler frequency filter ΔF _D, the expression ΔV = ΔF _D λ / 2, where λ - wavelength of the radiation, determining the Doppler frequency ΔF _DC band occupied signal reflected from the target, determining the target movement velocity band V _U occupied signal reflected from the target from the expression ΔV = ΔF _{U DC} λ / 2, determining the relationship β = ΔV _D / ΔV, while if β <0,01, decide on the spot at the target speed, and if β> 0.01, a decision is made on a speed-extended target, characterized in that the selection of the extended target is carried out in accordance with the expression: β = ΔV _C / ΔV at a given distance from the target, in the case if β≥ β _1, decide small target in case β≥β _2, decide average target in case β≥β _3, decide to large target, wherein prev agaemye inequality unambiguously determine the target class for the following values values $${\beta }_{\mathrm{one}}=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=0.05$$

$${\beta }_2=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=\mathrm{0.25,}$$

$${\beta }_3=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=\mathrm{0.40.}$$

2. The target class recognition device comprises a transmitter, an antenna switch, an antenna and a receiver, a recognition channel, while the first, second and third outputs of the transmitter are connected respectively to the first input of the antenna switch, the second and third inputs of the recognition channel, the first input of which is connected to the output the receiver, the second input-output of the antenna switch is connected to the output-input of the antenna, and the output to the input of the receiver, the second output of the transmitter and the output of the receiver are connected to the inputs of the all-round indicator p a diode station, and the transmitter contains a modulator, a microwave generator and a key, the output of the modulator connected to the first input of the key, the second input of which is connected to the output of the microwave generator, the outputs of the key, modulator and microwave generator are the first, second and third transmitter outputs, and the recognition channel contains a delay line connected in series, a key, a mixer, a Doppler frequency filter, a signal duration meter, a calculator, and a threshold device, while the first, second and the third inputs of the recognition channel are, respectively, the second key input, inputs of the delay line and mixer, and the first and second outputs of the threshold device are the first and second outputs of the recognition channel, characterized in that an additional selection channel for extended targets is added, the indicator is small target, the indicator is medium target , the indicator is a large target, the first, second and third inputs of the selection channel for extended targets are connected respectively to the first output of the transmitter, the output of the receiver and the second output of the channel I, the first, second and third outputs of the selection channel for extended targets are connected respectively to the inputs of the indicators: small target, middle target and large target, the selection channel for extended targets contains an OR element, a differentiating circuit, a shift register, the first, second, third and fourth elements are NOT, signal generator, first, second and third elements AND, counter, first, second, third and fourth threshold devices, first, second and third keys, signal generator, while the first, second and third inputs of the selection channel of extended targets are the first and second inputs of the OR element, the second inputs of the second, third and fourth threshold devices, the input of the differentiating circuit is connected to the first output of the transmitter, and the output is connected to the second inputs of the shift register and counter, the output of the OR element is connected to the first input of the shift register, the third input of which is connected to the output of the pulse generator, the first and second outputs of the shift register are connected, through the first element NOT and directly, with the first and second inputs of the first element And, the third input which is connected to the output of the pulse generator, the output of the first element And, through the first input of the counter, is connected to the second input of the first threshold device, the second input of which is connected to the first output of the signal generator, the output of the first threshold device through the second element is NOT connected to the second inputs of the first, second and third keys, the first inputs of which are connected to the second, third and fourth outputs of the signal setter, and the outputs of these keys are connected respectively to the first inputs of the second, third and fourth threshold devices, the threshold value of the signal for the first threshold device is set at the first output of the master depending on the specified range to the target, the threshold values of the signals of the second, third and fourth threshold devices are set at the second, third and fourth outputs of the signal generator, while the threshold values signal values β ₁ ; β ₂ ; β ₃ ; are determined in accordance with the following values: $${\beta }_{\mathrm{one}}=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=0.05$$

$${\beta }_2=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=\mathrm{0.25,}$$

$${\beta }_3=\frac{\Delta V_{\mathrm{Ts}}}{\Delta V}=\mathrm{0.40,}$$

the output of the second threshold device is connected to the first input of the second AND element, the second and third inputs of which are connected to the outputs of the third and fourth elements NOT, the output of the third threshold device is connected simultaneously with the input of the third element NOT and the first input of the third AND element, the second input of which is connected to the output the fourth element is NOT, the output of the fourth threshold device is connected to the input of the fourth element is NOT, the outputs of the second, third elements And and the fourth threshold device are respectively ervym, second and third elongated output channel selection purposes.