RU2153684C1 - Method for protection of radars against antiradar missiles - Google Patents

Abstract

FIELD: passive methods for protection of radars against homing weapon, in particular, against antiradar missiles equipped with passive radar homing heads. SUBSTANCE: the method is based on opposite action to antiradar missiles for a self-contained and highly mobile radar (antiaircraft guided missile system) functioning in travel and in position, in the absence of interacting radars, time and means for arrangement of equipment for remote radiation measurement. According to the offered method, a decoy rocket launcher should be installed on board (chassis) of the protected radar (antiaircraft guided missile system) capable of changing the angle of take-off of decoy rocket, determining the direction to the used antiradar missile, its range and velocity, from which it is necessary to launch an unguided decoy rocket carrying a microwave signal generator to meet the approaching antiradar missile with a certain angular displacement (angle α_dis) relative to the direction to it. The parameters and level of the signal produced by the generator and propagating in the direction of the antiradar missile should correspond to the signal parameters of the protected radar. Due to the angle of displacement, the antiradar missile is led away from the point of the radar position. It occurs due to the fact that the homing head of the antiradar missile reinterprets the signal of the decoy rocket since at the moment of its launching radar radiation is stopped. In this case there is an inconsiderable probability of trapping of the antiradar missile, which does not reduce in any way the efficiency of employment of the decoy rocket, but, on the contrary, provides for premature destruction of the antiradar missile and, respectively, the safety of the radar. Otherwise, the antiradar missile continues moving, but already with a changed trajectory, which in turn results in a miss of the antiradar missile. After a launch of the decoy rocket radar radiation is switched off. It is done so as to prevent a lock-on of the radar signal by the head of the antiradar missile after a fly-by of the decoy rocket. The magnitude of leading-away of the antiradar missile from the point of the radar position and, consequently, the probability of radar protection is the higher the larger the angle of displacement and the flight time of the decoy rocket. After fly-by of the antiradar missile, in time t = D_arm/V_arm, radar radiation is switched on again. EFFECT: enhanced efficiency. 5 dwg

Description

 The invention relates to passive methods of protecting radar stations (radar) from homing weapons, in particular from anti-radar missiles (PRR) equipped with passive radar homing heads (GOS).

As one of the passive methods, the shift of the guidance point away from the suppressed radar is widely used. Such an offset can be created in known methods by using additional radiation sources (DII) and various kinds of rereflectors [1,2]. The offset of the homing point can also be created due to irradiation of the underlying surface [3]. This method is effective and quite simple, but it works only in limited conditions, since the angle of the radar surface should be less than 15 ^o from the normal. In addition, there is a method of selecting a direct signal against a background of a signal reflected from the underlying surface [4].

 There is also a method of using N DII [5], made in the form of transmitters with antennas that can withstand the effects of an explosion of the warhead of the PRR. Such transmitters may be coherent and incoherent. In the case of using an incoherent source, its signals have time and frequency parameters that differ from the parameters of the probing radar signal, which makes it possible for the radar detector to select the radar signal against the background of DII signals in frequency and time parameters. The probability of targeting the GPR PRS to the radar signal in the case of preliminary reconnaissance, for example before launching the PRR, is approximately 1, and in the case of independent reconnaissance of the GOS during the flight 1 / (1 + N). When using coherent sources, the parameters of the signals emitted by additional sources coincide with the parameters of the probing signals (RS) of the radar. In this case, the signals from all additional sources will change along with the change in the parameters of the ES of the radar, and the GOS PRR will search again for the time and frequency parameters of the emitted signals. The probability that the homing radar will choose a radar among N false sources under the above conditions is 1 / (1 + N) [1,2].

 There is another method of protection against PRR [6], which consists in the fact that N DII are used to protect M radars. In this case, DIIs are located from the perimeter of group M of the radar at distances not less than the radius of destruction of the warhead (warhead) of the PRR and not greater than the direct line of sight of the radar. A group of M radars should be able to programmatically review the space. The time and frequency parameters of DII can be controlled by any station from the group, excluding the possibility of controlling DII at the same time by two or more radars. At the same time, the period of radiation of distracting signals of DII should be less than the constant control loop of the PRR.

This method has the following significant disadvantages that reduce its effectiveness and cost:
antennas and design elements of DII must withstand a possible close detonation of warhead PRR, which can be achieved by using armor or reducing the size, and this in turn leads to high cost and complication of the design of DII;
to implement the method, it is necessary to change the parameters of the radar probe signals from the group in order to obtain normal variations to the phase front of the total emitted waves, which does not allow the method to be used to protect one radar;
the radar group must necessarily have the ability to programmatically review the space, which leads to the complication of radiation devices and processing of radar information, which also increases the high cost of the method;
the use of N DII as elements of protection of the M radar will have a tangible effect on the deployment and coagulation time of the M radar on the ground;
to bring DII into working condition, additional time and an increase in human costs are required, which in turn cannot but affect the mobility of the used radars;
for the method under consideration, it is necessary that the protected radars do not change the coordinates of the standing point, which deprives them of the ability to move during operation and increases their vulnerability;
all parts of the device should be located relative to each other at a distance providing electromagnetic compatibility [7], but not more than the line of sight.

 The main disadvantage of this method is the inability to use it for an autonomous radar or anti-aircraft missile system (SAM), constantly changing their location (position), conducting combat work in motion.

 The purpose of the invention is to develop a method of countering the PRR for an autonomous and highly mobile radar (SAM), conducting combat work (functioning) in motion, in the absence of interacting radar, time and means for placing DII.

To achieve this goal, the authors propose aboard an autonomous single radar capable of operating on the move and in place, installing a missile trap missile launcher and determining the direction of the anti-radar missile, its range and speed. The trap missile launcher is deployed at an angle α _cm equal to half the width of the antenna pattern of the trap missile, and an uncontrolled trap rocket is launched with the distracting signal transmitter turned on, at an angle α _cm relative to the direction of the anti-radar missile. The repetition period of the emitted distracting signals must be less than the time constant of the anti-radar missile guidance control loop. Simultaneously with the launch of the trap missile, the radar radiation is turned off, which is turned on after time t = D _prr / V _prr , where D _prr is the range to the anti-radar missile, V _prr is the speed of the anti-radar missile.

According to the proposed method (Fig. 1) on board (on the chassis) of the radar (SAM), it is necessary to install a trap missile launcher that can change the launch angle of the trap missile, determine the direction of the anti-radar missile used, its range and speed from which to meet an approaching PRR with some angular displacement (angle α _cm ) relative to the direction to it, it is necessary to launch an uncontrolled missile trap with a microwave signal generator placed on it. The parameters and level of the signal generated by the generator and propagating in the direction of the PRR must correspond to the signal parameters of the protected radar.

Due to the presence of a displacement angle, the PRR is removed from the radar station point. This is due to the fact that the GPR PRR intercepts the signal of the trap missile, since at the moment of its launch the radar radiation ceases. At the same time, there is an insignificant possibility of getting the PRR into the trap, which not only does not reduce the effectiveness of using the trap missile, but, on the contrary, provides premature undermining of the PRR and, accordingly, the radar safety. Otherwise, the PRR continues to move, but with a changed trajectory, which in turn leads to a miss of the PRR. After the launch of the trap missile, the radar radiation is turned off. This is done in order to exclude the possibility of capturing the radar signal by the PRR head after the passage of a trap missile. The magnitude of the withdrawal of the PRR from the radar's standing point and, therefore, the probability of radar protection, the greater, the greater the angle of displacement and the flight time of the trap. After the flight of the PRR past the trap missile, after a time t = D _prr / V _prr , the radar radiation is switched back on.

It was previously assumed [8] to use a repeater amplifier as a source of radiation from a trap missile. In this case, the choice of a generator rather than an amplifier relaying radar signals as a source of microwave oscillations is due to a number of reasons:
the magnetron proposed as a generator in comparison with other devices has the highest efficiency and specific power per unit weight;
the use of a repeater amplifier necessarily introduces a delay of the radar pulse front by l / ΔF _d , where ΔF _d is the bandwidth of the amplifier path, which can lead to temporary resolution of the leading edges of the pulses emitted by the radar and the trap missile;
in the dimensions of the trap missile, it is difficult to provide the necessary isolation of the receiving and transmitting antennas.

The signal level from the trap missile should be not less than the signal emitted by the radar in the direction of the PRR. In other words, the inequality
P _l • G _l ≥ P _radar • G _radar • g,
where P _radar , G _radar - power of the transmitting device and the gain of the radar antenna;
P _l , G _l - the power of the transmitting device and the gain of the antenna of the trap, respectively;
q = 0 ... 1 is the value of the directivity factor of radar radiation on the PRR.

где S_a = πR $\genfrac{}{}{0ex}{}{\text{2}}{\text{л}}$ - площадь раскрыва антенны ловушки;
λ - длина волны РЛС (ракеты-ловушки).To justify the necessary radiation power of the trap missile, we will use the well-known expression for the gain of aperture antennas [9, 10, 11,]:

where S _a = πR $\genfrac{}{}{0ex}{}{\text{2}}{\text{l}}$ - the aperture area of the antenna traps;
λ - wavelength of the radar (missile trap).

Поскольку размеры пускового устройства ЗРК ограничены размерами шасси, то и размеры пускового устройства ракеты-ловушки, как и сама ракета-ловушка, будут ограничены. Это в свою очередь накладывает жесткие требования на массу и калибр ракеты-ловушки. Диаметр антенны ракеты-ловушки при этом не может превышать 100-120 мм. С учетом этого, а также того, что уровень диаграммы направленности антенны в направлении на ПРР будет составлять 35-40 дБ, требуемая средняя мощность передатчика ракеты-ловушки в соответствии с (1) составит
при P_рлс = 1.9 кВт, G_рлс = 4300, q = 5•10^-4, λ = 4 см, R_л= 5.5 см, P_л ≥ 55 Вт.The required average transmitter power of the trap-missile, taking into account the guidance of the PRR on the background radiation of the radar, is expressed by the formula

Since the size of the SAM launcher is limited by the size of the chassis, the dimensions of the trap missile launcher, as well as the trap missile itself, will be limited. This in turn imposes stringent requirements on the mass and caliber of the trap. The diameter of the antenna of the trap missile in this case cannot exceed 100-120 mm. With this in mind, as well as the fact that the antenna radiation pattern level in the direction of the PRR will be 35-40 dB, the required average transmitter power of the trap missile in accordance with (1) will be
at P _radar = 1.9 kW, G _radar = 4300, q = 5 • 10 ^-4 , λ = 4 cm, R _l = 5.5 cm, P _l ≥ 55 W.

The interaction of the protected radar, the launch device of the trap missile and the trap rocket itself is as follows. As can be seen from (Fig. 1), target 2 launches PRR 3 on a functioning radar 1. Radar 1 must be detected and recognized by PRR using known methods. One of them is described in [12]. There are also other special PRR recognition algorithms. As signs characterizing the attacking PRR, can be used:
PRR scattering polarization matrix;
radial component of the velocity of the PRR;
the length of the PRR in the direction of radiation;
PRR motion parameter.

After detecting and recognizing PRP 3, information on the signal parameters of the protected radar 1 and the coordinates of the detected PRP 3 is sent to the control device for launching missile traps. Based on this information, the repetition rate of the pulses emitted by the trap missile is linked to the repetition rate of the pulses emitted by the radar 1. If in radar 1, pulse-frequency tuning of the carrier frequency is used, then before launching the trap missile, radar 1 switches to the frequency at which the trap-generator operates. After that, from the radar 1, the launch of the trap-rocket 4 is carried out with a certain shift by an angle α _cm relative to the line of sight D, (radar 1 - PRR 3). At the time of launch of the trap-rocket 4, the radar 1 radiation is turned off. GSP PRR 3 intercepts the signal of trap-rocket 4, as a result of which PRR 3 changes its guidance path from D to S. In the case of using a radar pulse signal, the repetition period of the emitted distracting signals must be less than the time constant of the PRP guidance loop. This is necessary in order for the PRR rudders to have time to work out for the GPR PRR with the accompanying missile traps. Using this method provides effective protection of the radar from PRR and eliminates a number of disadvantages inherent in previously known methods:
there is no need to use DII with booking nodes and elements;
the proposed method allows you to protect both the radar group and a separate station, which in turn may not have a program view;
the lack of time for deployment and deployment of the launcher allows you to solve the problem of separation of human resources from performing direct duties;
The question related to the diversion of time for the deployment of N DII is addressed.

 In FIG. 1 shows the use of an additional radiation source made in the form of an uncontrolled missile trap. A trap missile is used to protect an autonomous and highly mobile radar (SAM), conducting combat work on the move and in place, in the absence of interacting radar, time and means to place around N DII. An embodiment of a structural diagram of a trap rocket is shown in FIG. 2. The synchronization pulses from the protected radar are fed to a synchronized generator, which is powered by an electrochemical power source. The synchronized generator provides synchronous operation of the radar transmitter and trap missiles, respectively, and generates the signals necessary for the operation of the converter-modulator. The converter-modulator creates the start pulses of the microwave signal generator. Further, through the antenna-waveguide path, the pulses of the microwave signal generator of the trap-rocket, identical in their parameters to the pulses of the microwave signal generator of the radar, are radiated into space.

The launch of the trap missile is carried out at the time of the approach of the PRR to the radar at a distance that provides reliable capture of the signal of the trap rocket of the GOS PRR. Therefore, for a longer-term impact on the GOS PRR, the launch of the trap rocket should take place in such a way that the displacement angle of the start of the trap rocket (from the direction to the PRR) is equal to half the width of the radiation pattern, ( _2Θ ^o _0.5p ) of the trap antenna. In FIG. Figure 3 graphically demonstrates the rationale for the launch angle of a trap rocket.

(фиг. 3а) уменьшается кривизна траектории увода ПРР от подавляемой РЛС.When

(Fig. 3a) decreases the curvature of the trajectory of the withdrawal of PRR from the suppressed radar.

(фиг. 3в) воздействие излучения ракеты-ловушки на ГСН ПРР будет минимизировано.For

(Fig. 3c) the effect of radiation from the trap-rocket on the GOS PRR will be minimized.

достигается максимальный эффект воздействия сигнала, излучаемого ракетой-ловушкой на ГСН ПРР.From FIG. 3b shows that it is precisely when

the maximum effect of the signal emitted by the trap missile on the GPR PRR is achieved.

где m - коэффициент пропорциональности, учитывающий закон распределения амплитуд на раскрыве, равен 65-80^o;
λ - длина волны;
d -диаметр антенны ловушки.For mirrored antennas, most commonly used in the warheads of missiles, the radiation pattern width (WID) is equal to

where m is the coefficient of proportionality, taking into account the law of distribution of amplitudes in the aperture, is 65-80 ^o ;
λ is the wavelength;
d is the diameter of the antenna trap.

Thus, knowing the necessary parameters λ = 4 cm, d = 11 cm, we can calculate _2Θ ^o _0.5p = (23.6 ^o -29 ^o ), and the angle of displacement α _cm = (11.8 ^o -14.5 ^o ).

 The main advantage of this method is the possibility of its use for an autonomous radar (SAM), constantly changing its location (position), conducting combat work on the move and in place.

Used Books
1. Golovin S.A., Sizov Yu.G., Skokov A.L., Khundanov L.L. Precision weapons and the fight against it. M .: Publishing house "Arms. Politics. Conversion.", 1996.

 2. Nebabin V. G., Kuznetsov I. B. Radar protection from PRR // Foreign electronics. 1991 N4. S. 67-81.

 3. Volzhin A.N., Sizov Yu.G. Fight against homing missiles. M., Military Publishing, 1983.

 4. Patent 3757326 (USA), cl. G 01 S-9/32.

 5. Patent 4698638 (USA), cl. G 01 S-13/10.

 6. RF patent N 2099734 dated 12/20/97, A. Ivashechkin, G. Leonov. A method of protecting a group of radar stations from anti-radar missiles using additional radiation sources and a device for its implementation. Application N 96103564/09. Priority 02/23/96 (prototype).

 7. Komissarov Yu.A., Rodionov S.S. Immunity and electromagnetic compatibility of electronic equipment. Kiev, Technique, 1978.

 8. Gusev VP, Tolkachev AM The use of unguided missile traps for the protection of ground forces from precision weapons // Materials of a scientific and technical conference. - Kiev: KVZRIU, 1983. S.23-28.

 9. Markov G.T. Antennas Textbook for high schools. - M.: Energy, 1975 .-- 528s.

 10. Antennas and microwave devices. Ed. D. I. Voskresensky - M .: Radio and communications, 1981. -432s.

 11. Finkelstein M. I. Fundamentals of radar. M .: Radio and communication. 1983 .-- 536 p.

12. RF patent N 2097782. Ermolenko VP, Mitrofanov DG. Device for recognition of anti-radar missiles. IPC ⁶ G 01 S 13/02. Application N 96109815. Priority 05.21.96, Publ. 11/27/97

Claims (1)

A way to protect the radar from anti-radar missiles, which consists in the fact that distracting signals are emitted, and the repetition period of the emitted distracting signals must be less than the time constant of the anti-radar missile guidance control loop, characterized in that it is on board an autonomous single radar capable of moving in place and in place , set the trigger device for missile traps, determine the direction of the anti-radar missile, its range and speed, deploy the trigger device about missile traps at an angle of α _cm equal to half the width of the radiation pattern of the antenna of the missile trap, and launch an uncontrolled missile trap with the transmitter for distracting signals at an angle of α _cm relative to the direction of the anti-radar missile and turn off the radar radiation, which turn on after time t = D _prr / V _prr , where D _prr is the range to the anti-radar missile, V _prr is the speed of the anti-radar missile.

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