RU1841319C - Missile decoy to counter radar missile guidance systems - Google Patents

Abstract

FIELD: defence, armament.

SUBSTANCE: invention relates to compensatory methods for protecting the selection channels of radar guidance systems for guided missiles. Declared missile trap to counter radar guidance systems for guided missiles contains an active repeater with modulation devices. Additionally, a microwave splitter is installed on the rocket, which supplies part of the probing signal energy to the irradiation type selector, the irradiation type selector, which connects one or another noise generator to the modulator to create a response signal, the spectral band of which is consistent with the type of probing signal, and a control circuit that corrects the position of the narrow-band of the noise spectrum on the frequency axis during the flight of the trap according to commands initiated immediately before the launch of the trap from the aircraft system for analyzing the combat situation.

EFFECT: increased efficiency of transferring tracking systems of homing heads (HH) to tracking a decoy missile and using the energy of a repeater for various types of probing signals.

1 cl, 5 dwg

Description

The invention relates to compensatory methods for protecting the selection channels of radar guidance systems for guided missiles. The compensation method for protecting the selection channels of radar guidance systems for guided missiles is an effective means of combating the effects of noise and speed-shifting interference, as well as passive traps.

The essence of the method consists in compensating the dynamics of diverting interference by introducing corrective corrections to the probing signal of the ROC, providing an almost instantaneous transition from tracking the interference signal to tracking the target signal by changing the carrier frequency of the target illumination signal.

To generate a correction and correction signal in the RPC, a multi-channel survey receiver is used. The analysis of signals in the survey receiver is carried out by a digital computer, which makes it possible to quickly calculate the necessary corrections. The use of a surveillance receiver and a digital computer makes it possible to automatically switch from tracking interference to tracking a target or, with the help of an operator, switching from tracking one target to tracking another.

In the presence of noise interference, the tracking system is turned off to avoid random drift and capture of the "zero" signal, and the tracking filter is forcibly tuned towards higher Doppler frequencies at a certain constant speed. A special tracking system provides tracking of the upper end of the interference spectrum (with narrowband noise). After turning off the interference, the search machine or the operator surveys a certain section of the speed range and, if there is a circuit signal in it, captures it. Since the time and speed of the forced tracking filter adjustment are known, the search can be performed in a limited range at a high speed, which ensures that information gaps are reduced to an acceptable value.

The application for the invention proposes a method for overcoming compensatory protection using active decoy missiles.

The effectiveness of this method is based on the fact that the equipment of the trap, re-radiating the probing signal of the radar, endows it with the appropriate noise modulation, which violates the resolution of the selection channels. Under these conditions, when even the radar operator does not observe the target signal, the use of compensation protection is excluded.

If the radar operates in the range and speed selection mode, for example, with phase-code keying of the probing signal, then the trap should emit broadband noise. Then the operator, without selecting the trap in range, will switch to the non-manipulated signal mode in the hope of using the radar energy wisely and distinguishing the target signal against the background of broadband noise. In this case, the trap must start emitting narrowband noise so that the repeater power is used efficiently and the radar system does not receive energy advantages due to a change in the radiation mode.

After that, as noted above, the tracking filter of the GOS switches to tracking the upper edge of the noise interference spectrum, i.e. The seeker accompanies the trap signal.

From an energetic point of view, it is desirable that the trap repeater emit a signal whose noise spectrum would be possibly narrower, but at the same time compensate for the inaccuracy of pointing the masking spectrum to the frequency of the target signal.

To do this, the narrow-band noise emitted by the trap during its flight is smoothly shifted along the frequency scale so that it masks the target signal for as long as possible. The choice of the noise displacement law is determined by the data received from the aircraft system for analyzing the combat situation immediately before the launch of the trap.

Since the Doppler frequencies of the target and the trap differ from each other after the start of the trap, no special requirements for residual suppression at the carrier frequency can be imposed.

Below, a device is proposed that implements the considered method of using active decoy rockets to overcome compensation protection.

The block diagram of this device is shown in fig. 1 showing:

1 - receiving antenna;

2 - transmitting antenna;

3 - microwave splitter,

4 - input TWT,

5 - output TWT,

6 - selector for the type of irradiation,

7 - narrowband noise generator,

8 - broadband noise generator,

9 - modulator,

10 - sawtooth voltage generator (GPN),

11 - control scheme.

Device description

The microwave signal of the target illumination station (RPC) is received by the receiving antenna (1) and fed to the input of the splitter (3). Here it branches into two channels. One channel is a repeater channel. The second channel is a selector channel for the form of exposure. The irradiation type selector is designed to determine the operating mode of the RPC (phase code keying (PCM) or continuous radiation) and issue commands for the necessary switching in the trap equipment. If the ROC operates with continuous radiation, then according to the retargeting method, the trap repeater must emit low-frequency noise. This is done by connecting the narrowband noise generator (7) to the modulator (9) using the mode selection relay located in the irradiation type selector. If the RPC operates in the FKM mode, then the mode selection relay connects a broadband noise generator (8) to the modulator (9). Modulator (9) is a broadband amplifier and is designed to amplify noise voltages to an amplitude sufficient for phase modulation of the microwave signal using LEV (4). The shift of the spectrum of low-frequency noise to compensate for the acceleration of the trap is carried out using a sawtooth voltage generator (10). The frequency control of the GPN is produced by the control circuit (11), which develops the law of frequency change depending on the data received from the combat situation analysis system. Amplified by two LEVs (4, 5), the signal from the ROC is re-radiated into space using a transmitting antenna (2).

The proposed device is designed for the case when the ROC can change the radiation mode both before and after the rocket launch. If it is known that the ROC can change the radiation mode only before the launch of the attacking missile, i.e. until the moment the trap is launched, then switching the operating modes of the trap equipment can be performed by commands from the selector of the type of exposure available in the on-board jamming station.

In this case, the block diagram of the device is simplified (Fig. 2). Instead of the irradiation type selector, only the operating mode selection relay (6) is installed, and the splitter (3) (Fig. 1) is eliminated.

Implementation of the considered device presents no technical difficulties. This can be seen if we consider as an example the possible options for constructing some of the most complex elements of the device.

The irradiation type selector is an autocorrelation scheme (Fig. 3). The input of the circuit after the directional coupler (3, Fig. 1) receives a microwave signal, which is branched using a power divider (Fig. 3) into two channels. The division ratio of the divider (1) is chosen so that the signal powers at the inputs of the adder (3) are equal. The microwave delay line (2) provides a signal delay for a time less than the duration of the FKM sample (of the order of 0.15 μs). From the output of the adder (3) the microwave signal arrives at the detector head (4). When a phase jump occurs in the microwave signal, a pulse appears at the output of the detector head, which is differentiated and amplified by an amplifier-shaper (5), at the output of which there is a storage circuit connected to the power circuit of the operation mode selection relay (6). If the signal is continuous and FCM is absent, then the relay is de-energized and the narrow-band noise generator is turned on. The appearance of a signal from the FCM at the input of the repeater causes the relay (6) to operate and the broadband noise generator to turn on.

The narrowband noise generator (7) can be assembled according to the scheme of Fig. 4. Noise source (1) generates white noise. The noise voltage is amplified by a broadband amplifier (2) and fed to the input of a narrowband amplifier (3).

The broadband noise generator (8) differs from the low-frequency noise generator only in the extended bandwidth of the amplifier (3).

The sawtooth voltage generator (10, Fig. 5) generates a sawtooth voltage, the frequency of which can vary according to a given law, the GPN consists of a master oscillator (1) and an amplifier (4). The master oscillator is a conventional sawtooth voltage generator. To change the frequency of the generated oscillations in the charge circuit of the time-setting capacitance C, there is a device (2) (for example, a transistor), which changes the charge time constant. The discharge of capacitor C occurs through circuit (3), which had a thyratron characteristic.

The control circuit converts commands from the programmer to voltages, which are used to control the change in the frequency of the FPV and to adjust the band of narrow-band low-frequency noise.

Claims (1)

A trap missile for counteracting radar guidance systems for guided missiles, containing an active repeater with modulation devices, characterized in that, in order to increase the efficiency of transferring the tracking systems of the homing head to tracking the trap missile, an irradiation type selector channel is introduced into it, consisting of an ultra-high splitter frequency and radiation type selector and connected in parallel to the repeater channel, and a control unit, the output of which is connected to the sawtooth voltage generator.

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