JPH0474987A - Electronic opposing system - Google Patents

Abstract

PURPOSE: To jam a spotter radar effectively by matching the timing and frequency of a pulse with those of a reflection signal from a target plane when an electronic intercepting system is mounted on a decoy plane and a radar pulse is transmitted under control of a data link. CONSTITUTION: The electronic intercepting system for concealing a friendly plane (target plane) 14 from spotter radars 10, 12 comprises a spatter radar detection system mounted on the target plane 14, a decay signal transmission system mounted on a decoy plane 16, a data link between the target plane 14 and the decoy plane 16, and a signal analyzer mounted on the target plane 14 and measuring the distance between the target plane 14 and the decoy plane 16. When a radar pulse having calculated delay and Doppler displacement is transmitted from the spotter radar detection system mounted on the target plane 14 under control of the data link, the timing and frequency of the pulse are matched with those of a reflection signal from the target plane 14. According to the system, the target plane 14 is concealed from enemy side spotter radars or the position thereof is recognized erroneously and the friend plane can be protected against attack from an enemy plane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic countermeasure system for concealing friendly aircraft (hereinafter referred to as target aircraft) from enemy search radar.

[Prior art] Interfering with enemy search radar signals (hereinafter referred to as jamming)
There are two ways to do this: scattering a large number of metal flakes from the target aircraft into the air, which reflect a large number of signals to the radar, making it difficult to identify the target aircraft, and radar signals from a search radar. Based on this, there are active measures such as creating and transmitting false signals to mislead enemy search radars as targets.

[Problem to be solved by the invention]

Although the use of spurious signals to confuse search radars is desirable for jamming, current radar systems are highly complex and cannot be used to confuse one or more search radars. , allowing target aircraft to penetrate defense systems and evading radar-guided missiles has become difficult. In particular, in reality, enemy search radars use techniques such as pulse-to-pulse code conversion, chirping, or variable frequency pulses, making jamming extremely difficult.

The present invention aims to provide an electronic countermeasure system that makes it possible to solve this difficulty.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows.

A radar jamming system consisting of a target aircraft and a decoy aircraft, which includes a search radar detection system installed on the target aircraft, a decoy signal transmission system installed on the decoy aircraft, and a data link between the target aircraft and the decoy aircraft. A signal analysis device installed on the target aircraft that can measure the distance between the target aircraft and the decoy aircraft, calculates the amount of signal delay and Doppler displacement required to conceal the target aircraft, and transmits the calculated signal to the previous A means for transmitting a radar pulse to a decoy aircraft via a data link, and a means for transmitting a radar pulse having a calculated delay amount and Doppler displacement amount by being mounted on the decoy aircraft and controlling the data link to target the pulse. an electronic countermeasure system comprising means for time and frequency matching of reflected signals from an aircraft.

An electronic countermeasure system mounted on a target aircraft that detects and analyzes search signals and transmits signals to control radar signals from decoy aircraft, and receives one or multiple independent search radar signals. The distance between the decoy aircraft and the target aircraft is determined by measuring and calculating each received signal using multiple receiving antennas and multiple transmitting antennas.
and the frequency difference (Df) and arrival time difference (D
means for measuring and calculating the amount of delay and Doppler displacement of the necessary radar signal sent from the decoy aircraft for each enemy search radar signal in order to conceal the reflected signal from the target aircraft; , providing the decoy with appropriate signals regarding the delay, Doppler shift, bandwidth, gain, and center frequency of the signal to be emitted by the decoy, such that the pulses match both time and frequency with the target signal; An electronic countermeasure system main radar countermeasure system comprising: means for detecting and receiving radar signals from a plurality of search radars; means for determining the search radars to be jammed and their priorities; A signal analysis device installed for each enemy search radar to measure and calculate the distance between the decoy aircraft and the target aircraft and the amount of change in distance; and a means for operating the decoy aircraft equipped with a jammer under the control of the signal analysis device. , a means installed in the signal analysis device for calculating a displacement amount and a delay amount to be added to the jamming signal in order to match the time and frequency to the reflected signal in order to conceal the reflected signal from the target aircraft; and means for transmitting control signals to the decoy device.

A radar jamming system for a decoy aircraft installed on a decoy aircraft that receives control signals from a target aircraft, which includes a data link decoder, a variable delay line, a Doppler frequency synthesizer, and the amount of delay and Doppler required for the radar signal. and means for transmitting the signal from the decoy aircraft in combination with the amount of displacement, and the means is controlled by a data link decoder to transmit the amount of delay and the amount of Doppler displacement so that the transmitted signal matches the reflected signal from the target aircraft. An electronic countermeasure system that defines the following.

The signal emitted from the decoy aircraft may be made to match the time and frequency of the reflected signal from the target aircraft captured by the enemy search radar to conceal the target aircraft.

The main anti-radar system includes means for detecting and receiving radar signals from multiple search radars, means for determining which search radars should be jammed and their priorities, and a signal analysis device installed for each search radar. Each signal analyzer measures and calculates the following: (a) the distance between the decoy aircraft and the target aircraft (B) (b) the direct incident signal and the signal transferred from the decoy aircraft; Delay as the time difference between the signal and the target (D do) (c) Change in distance between the decoy aircraft and the target aircraft (dB /d t) (d) Directly incident signal and transferred from the decoy aircraft Difference in frequency (Df) between signals (b), and means for inserting the calculated Doppler displacement amount and delay amount into the enemy search radar signal and retransmitting it, and reflecting the retransmission radar signal emitted from the decoy aircraft at the gate cost aircraft. An electronic countermeasure system that emits enemy search radar signals in phase, code, and time, making the signal strength from the decoy aircraft greater than the signal reflected from the target aircraft, and emitting it from a different angle.

An electronic countermeasure system installed on a target aircraft that detects and analyzes search radar signals and controls the radar signals using a decoy aircraft, which includes one receiving unit that receives one or multiple separate search radar signals. an antenna and a plurality of transmitting antennas, and means for calculating, for each received signal, the following: (a) the time difference between the search radar pulse directly incident on the target aircraft and the value transmitted from the decoy aircraft; (D do) (b)
Doppler amount (dB/dt) of the signal from the decoy aircraft to the target aircraft (
c) The angle between the decoy aircraft and the enemy search radar as seen from the target aircraft (
∠A) (d) Frequency difference (Df) between the signal directly incident on the target aircraft from the enemy search radar and the signal transferred from the decoy aircraft Calculate the values of Dp, Ds, and C using the following formulas. Means for
A-1) + 2Ddoco However, Dp: Doppler displacement amount given to the jammer signal so that the signal from the gunner from the decoy aircraft matches the Doppler amount of the target aircraft captured by the enemy search radar DS: The amount of Doppler displacement given to the jammer signal from the target aircraft on the enemy search radar The amount of delay C given to the signal emitted from the decoy aircraft's jammer is the distance between the target aircraft and the enemy search radar, and the time and frequency of the transmitted signal from the decoy aircraft are An electronic countermeasure system designed to match the reflected signal of

The amount of delay given to the signal transferred from the decoy device is Ds=2B
The reflected signal from the target aircraft received by the enemy search radar may be concealed by delaying by the Ds value calculated by -2Ddo.

The Doppler position given to the signal transferred from the decoy aircraft may be shifted by the Dp value calculated by Dp = dB/dt - Df to match the Doppler amount of the target aircraft received by the enemy search radar. .

The distance C between the target aircraft and the enemy search radar is expressed as C=Ddo(2B-Ddo)/[2B(cosA
-1) + 2 Ddol However, A may be calculated using the angle Ds=2B-2Ddo between the enemy search radar and the decoy aircraft as seen from the target aircraft.

The means for continuously monitoring the radar signals retransmitted from the decoy aircraft includes means for continuously measuring Ds and Ddf and calculating the difference value, and a means for continuously monitoring the radar signals retransmitted from the decoy aircraft, and a means for continuously measuring Ds and Ddf and calculating a difference value therebetween. On the other hand, it is equipped with means for calculating the Doppler displacement amount (Ds) and delay time (Ddf) of the radar signal transmitted from the decoy aircraft, and the time and frequency match the reflected signal from the target aircraft, but the angle is misidentified. The signal from the target aircraft may be concealed by transmitting a signal from the decoy aircraft.

[For production]

In the system of the present invention, a low-cost remotely controlled jammer (decoy) is placed between the target aircraft and the enemy search radar to be jammed.

The decoy aircraft acts as a signal repeater and adds a delay command to the reflected pulses received by the radar to ensure that the target aircraft is concealed. Furthermore, the decoy aircraft changes the frequency of the transmitted signal to precisely match the Doppler intensity of the signal returned from the target aircraft.

The target aircraft commands the address to the decoy aircraft, and each decoy aircraft
operating ten or more search radars in a single search frequency band channel, each covering pulse being matched to a pulse from the target aircraft 50 nanoseconds apart;
The Doppler frequency is set approximately 10 cycles lower than the Doppler filtering band of the enemy search radar.

The data link measures the distance between the decoy aircraft and the target aircraft. The data link also commands the amount of delay and Doppler displacement that the shroud should give to each search radar pulse.

The main unit mounted on the target aircraft measures the difference in arrival time between the pulse arriving directly from the enemy search radar and the pulse relayed by the shield. FIG. 1 shows the geometrical positional relationship and the mathematical formulas for calculating the necessary delay amount and Doppler displacement amount of the jammer.

The accuracy of these formulas and the ability of the main unit to accurately measure each quantity are key points of the system of the present invention.

The system of the invention enables defense against ships, aircraft, missiles and spacecraft. The exact implementation method is based on the protected airframe and operational scenario. However, in most cases an external jammer, called a slave, remote or jammer unit (generally placed between the target aircraft and the search radar) and a main unit mounted on the target aircraft are used.

Angle Disguise The primary function of the system of the present invention is to conceal the radar signals reflected from the target aircraft, essentially erasing or misrepresenting the angle information received by the search radar.

While range gate withdrawal is very easy to accomplish, it is practically undesirable to continue it throughout the erasure or misidentification of the angle. One advantage of jamming with angle cancellation is that the search radar being treated cannot sense that it is being jammed.

- Calculate the distance to the enemy search radar based on the angle between the emitter's position search radar and the enclosure, and the arrival time difference between the direct signal from the radar and the relayed signal (measured for the enclosure). can be calculated accurately. This is extremely useful for evaluating search signals, correctly determining jamming programs, launching additional shells, etc.

Non-cooperative Bistable Detection This jamming system can be used to detect flying objects, especially missiles heading toward a target aircraft. Increasing the baseline length with respect to the target aircraft is important when the target aircraft is close to the line of sight between the search radar and the target aircraft, and the wavelength of the reflected wave is extremely close to the wavelength of the direct pulse signal from the search radar, making it more accurate. This is useful for separating and measuring the range of a missile heading toward a target aircraft when accurate range measurement is not possible.

This information is used when a semi-active search missile is detected.
This is extremely beneficial, as it allows the correct concealment pulse to be output to the missile, just as it would for a search radar. If a medium-range search missile is detected, a medium-range decoy device can be launched at the correct time. Other targets can be detected bistablely by known means.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic diagram showing the relationship between a target aircraft, a plurality of enemy search radars, and a decoy jammer aircraft. Also, from this diagram, it is possible to derive a formula for calculating the amount of delay and amount of Doppler to guide the jammer aircraft based on the distance to the enemy search radar.

Figure 1 shows two enemy search radars (10) and (12).
The radar (10) is operating at frequency 1) and the radar (12) is operating at frequency (f2). For ease of understanding, these radars are
The delay time of the reflected signal from 4) and the amount of Doppler displacement of the signal are measured. Also shown in FIG. 1 is one shroud (16) equipped with a slave jamming module that generates a separate jamming signal for each search radar.

Regarding the first enemy search radar (10), the radar (10
) to the target aircraft (14) is "C1", the distance from the radar (10) to the shield (16) is "A1", and the distance between the shield (16) and the target aircraft (14) is rBJ. do.

For the second search radar (12), let the corresponding distances be "A2JrC2J and rBJ, and for the N-th search radar, rA n JrCn J and rB
Let it be J.

For convenience of explanation, each reference numeral in the following description and claims shall be used with the following meaning.

A: Distance between the enemy search radar and the aircraft B: Distance between the aircraft and the target aircraft C: Distance between the enemy search radar and the target aircraft ∠ A: Angle between the slave aircraft and the enemy search radar as seen from the target aircraft Df: Enemy search radar Ddo: Difference in frequency between the radar signal directly incoming from the radar and the radar signal transferred from the aircraft Ddo: The amount of delay in the signal retransmitted by the aircraft relative to the radar signal directly incoming from the enemy search radar without delay. Ddf + required amount of delay to conceal the target aircraft (7) Delay amount Dp between the signal retransmitted from the aircraft and the radar signal directly incoming from the enemy search radar: Matches the Doppler amount of the target aircraft receiving the enemy search radar Doppler displacement amount Ds given to the transfer signal from the aircraft: Delay amount f given to the transfer signal from the aircraft so as to conceal the signal from the target aircraft received by the enemy search radar: Frequency of the enemy search radar The signals will be shown with subcodes (1, 2, n) indicating the respective radars whose data values are measured and calculated.

The target aircraft shown in Figure 1 is equipped with an electronic system, the details of which are shown in Figure 2, and is configured to perform the following measurements and calculations.

a: Measured value of Ddo Time difference between the pulse that reaches the target aircraft (14) from the radar (10) along C and the pulse that passes through A and then is transferred without delay along B = frequency of Measured value of difference Df Doppler amount c of the signal incident on two paths (C and A + B): Measured value of ∠A (determined by the angle formed by C and B) Angle d corresponding to the length of A: Measured value of B by normal relay technology e: Measured value of the Doppler amount dB/dt of the signal arriving at the target aircraft along B from the decoy aircraft 16) f: Measured value of Ddf Along C from the radar (10) The time difference between the pulses reaching the target aircraft (14) at B and the pulses transmitted along B giving the correct amount of delay to conceal the target is calculated by the following formula: Ru.

Calculate Ds by Ds=2B-2Ddo.

Calculate Dp by Dp=dB/dt-Df.

C= D do(2B-D do)/[2B(c
The distance C is calculated by osA-1)+2D doco.

Here, Ddo, B and ∠A are the values described above.

Therefore, all values of Ds and Dp are transmitted to the aircraft (16), the amount of delay time and the amount of signal frequency displacement are added, and then retransmitted from the aircraft (16) to the enemy search radar (10). Control.

The main unit monitors the amount of delay added to the jammer signal and the amount of Doppler. The added new delay amount is Ddf-28-Ddo, and the Doppler amount is dB/dt.

If the radar signal is retransmitted without demodulation by the aircraft,
The effect of the aircraft will be similar to the pulse-pulse coding or chirp methods used in enemy search radars.

If the signal returned from the aircraft matches the signal from the target aircraft in both time and frequency, and the angular direction is different, the radar (10) will detect the signal even if the target aircraft is within the correct range. You will be measuring a disguised angle. If a strong signal returns from a false angular direction, the radar will not be able to correct this error.

The same measurement was carried out for the second enemy search radar (12), and the delay amount D
A signal obtained by adding s2 and the Doppler displacement amount Dp2 is sent back to the enemy search radar (12).

If there are n search radars, take n sets of measurements, calculate Dsn and Dpn, and apply to the jamming signal.

Ddo=A+B-C Measured value at target aircraft Df=DA/
dt+dB/dt-DC/dtMeasured value at target aircraft dB/dt-Dfl=Dpl, dB/dt-Df2
=Dp2゜---dB/dt -D fn=D pn
2(B-Ddol)=Dsl, 2(B-Ddo2)
=Ds2゜...2(B-Ddon)=dsnThe target aircraft sends Dsl, Ds2-Dsn; Dpl, Dp to the decoy aircraft.
2-Dpn values are provided with appropriate bandwidth, gain, and center frequency.

The decoy aircraft delays the first radar signal by Dsl and Dp
Add a Doppler amount of 1 and relay.

The decoy aircraft delays the second radar signal by Ds2 and Dp
Add the Doppler amount of 2 and relay.

The decoy aircraft delays the nth radar signal by Dsn, and
Add the Doppler amount of pn and relay.

FIG. 2 is a block diagram of the electronic system onboard the target aircraft (14) that performs the measurements and calculations described above and sends the necessary commands to the decoy aircraft (16).

The system comprises a receiving antenna (20) with low directivity and capable of covering the entire angular range. For this purpose, a microwave antenna that is omnidirectional and can cover the wavelength band of the enemy search radar can be used. as needed,
Two or more antennas may be combined to cover all angular ranges and bands.

The signals received by the antenna (20) are subjected to signal detection, classification,
It is sent to a verification system (22) where it is verified as a search radar signal, assigned a priority and forwarded to one of a plurality of signal analyzers (24).

The operation of the low directional receiving antenna and signal detection, classification and verification evaluation system is essentially similar to the technology used in ASPJ and current radar warning and return equipment. The operation of these circuits is to identify the search radars that are currently tracking the target aircraft, determine their priorities, and assign a signal analyzer to each search radar.

Once jamming is initiated, these circuits monitor the effectiveness of the jam, monitor the appearance of new search signals, and reallocate signal analyzers as necessary.

Additionally, a multiphase array transmitting/receiving antenna (26) is installed, which receives enemy search signals from each enemy search radar and transfers them to the decoy aircraft (16). These phased arrays are arranged at angles lA, ∠A2.
Measure ∠An. The received signal of the antenna (26) is
Through the multiplex switch (28), the baseband amplifier (30)
sent to.

The signal from the baseband amplifier (30) is sent to two correlators (32) and (36).

The correlator (32) is a variable delay amount correlator and a Doppler detector, and measures the delay jlDdo and the frequency displacement amount Df. Next, Ddo and Df for each enemy search radar
The measured value of is sent to a signal analyzer (24).

A data link correlator (36) measures the distance B and the Doppler displacement JidB/dt. This correlator (36) also measures the angle ∠A from the target aircraft to each decoy aircraft (16). Also, distance B and Doppler displacement dB
The measured value of /dt is sent to a signal analyzer (24), which calculates Ds and Dp for each search signal according to the following equation.

Ds=2B-2Ddo Dp=dB/dt-Df Furthermore, the signal analyzer calculates the distance C to each enemy search radar using the following formula.

C=Ddo(2B-Ddo)/[2B(cosA
-1) + 2 d do] When each decoy machine (16) is launched, the operating unit (34) of the data processing system determines the search signal to be intercepted and the search signal that is currently being intercepted. Also, the delay amount [)sl for each enemy search radar signal,
Ds2. Dsn.

and Doppler displacement amount D pi for each radar signal.

D p2. Encode D pn. These encoded signals are sent to a data link oscillator (38), an amplifier (
40), is sent back to the multiplex switch (28) and to the antenna transmitting to the required decoy device (16).

Further, the actuating unit (34) launches additional decoy aircraft as necessary and sends the latest enemy search signal status to the cockpit.

FIG. 3 is a block diagram of the jammer electronic system.

This system is controlled by encoded data transferred from the main data processing system mounted on the target aircraft (14), receives radar signals from one or more enemy search radars, and retransmits them. It is.

The slave (jammer) system detects various enemy search radar signals fl, f2 . It is equipped with an antenna (50) for receiving fn. It also receives data link signals from the main data processing system. The received signal is sent to a mixer (52) and a local oscillator (5
3) is mixed with the separated frequency fa output. Difference signal fl-fa from mixer (52).

f2-fa, fn-fa are fundamental band amplifiers (58
) will be sent to. The amplified signal is sent to a data link decoder (57) and a variable bandwidth and gain amplifier (58).

The data link decoder (57) sends appropriate bandwidth and gain control signals from the main data processing unit to the variable bandwidth and gain control circuit (58). The signal amplified by the circuit (58) is sent to the Bonnobe line (60).

Also, the data link decoder has a delay signal amount Dsl
Ds2. Dsn is sent to a delay contact placed at a required position on the delay line (60).

The delay line (60) produces a number of signals corresponding to the number of search radar signals received. At this time, the output from the delay line (60) is f1-fa delay amount Dsl f2-fa delay amount Ds2 fn-fa delay amount Dsn-;

Further, the data link decoder (57) sends the encoded values of Dpl, Dp2 and Dpn to the Doppler frequency synthesizer (59), and outputs Dpl, D of the required frequency.
The p2 and Dpn signals are output and sent along the output of the delay line (60) to the phase displacement Doppler generator (62) to output the next signal.

f 1- f a+ Dpl (delay Ji Dsl) f
2-f a+ Dp2 (delay amount Ds2) f n −
f a+ Dpn (delay amount Dsn) These signals are sent to a basic bandwidth amplifier (64) and a mixer (66), and the signal fa from the local oscillator (53) is also input to the mixer. The output signal of the mixer is as follows.

fl+Dpl (Delay amount Dsl) f2+Dp2 (Delay amount D 52) fn+Dpn
(Delay amount Dpn) These signals are sent to the transfer antenna (80) via the enemy search signal bandwidth amplifier (68), delaying the reflected wave from the target aircraft by the calculated value Ds, and delaying the reflected wave from the target aircraft by the calculated value Ds. It is sent back to each enemy search radar as a reflected wave that conceals the actual target aircraft and reveals a false target aircraft.

Although the signal analyzer (24) is shown as a separate block in FIG. 2, it is actually a single module incorporating a software program.

A signal analyzer assigned to a certain enemy search radar,
Measure Ddo, Df and signal input angle.

Next, the urgency of the enemy search signal is evaluated and the distance to the enemy search radar is calculated. If the enemy search signal requires urgent action, one or more decoy aircraft are automatically launched. Next, Ds and Dp for causing the decoy aircraft to output a pulse that conceals the target aircraft are calculated, and these values are transmitted to the decoy aircraft via a data link.

When the delay amount Ds and the Doppler displacement amount Dp are introduced into the decoy device, the decoy device starts jamming the enemy search radar. The signal analyzer checks that the decoy machine is outputting the correct concealment pulse, and if not, sends a correction command to the decoy machine.

During jamming, the signal analyzer continues to subtract and add Ds and Dp, and continues to calculate correction values for Ds and Dp, depending on changes in the relative positions of the enemy search radar, target aircraft, and decoy aircraft. and modify their values.

When jamming multiple enemy search radars at the same time, the delay unit of the decoy creates multiple delays for each received signal. For example, when jamming seven real-face radars, each signal is repeatedly delayed with seven different delay amounts, and one of them is
Give the correct amount of delay so that only the seeds become the correct concealment pulses.

The other six types of signals that are repeated for each enemy detection signal have a transfer duty rate of 40 to 100% of the decoy device, so as not to inhibit jamming and reduce jamming to the signal ratio. This can further confuse real face radars.

By the way, if some real-face radars are narrow-bandwidth pulse Doppler radars, multiple Doppler displacements are important. Adding to each Doppler quantity by generating a phase shift Doppler at a separate delay contact produces the effect of interfering with the signal ratio of the bare radar, which not only changes the duty rate of the decoy's transfer system.

By measuring the signal strength of the real-face radar, the distance to the real-face radar can be calculated, so the main unit can
It is possible to accurately calculate how many real-face radars are assigned to one decoy aircraft and, based on that, decide when to launch additional decoy aircraft.

A decoy is a simple repeater that simply introduces a delay and a Doppler displacement into the signal it relays, so it is unclear what type of pulse-pulse coding or Doppler displacement the bare-face radar uses. The effectiveness of jamming is unaffected even if

Similarly, pulse chirping does not reduce jamming. A decoy device relays the pulse without affecting its properties in any way.

Angular jamming is created by the arrival of two coherent signals at the face-on radar. One is
One is the correct angle signal from the target aircraft, and the other is the incorrect angle signal from the decoy aircraft. Since the two signals are coherent signals, the real-face radar cannot perform processing to separate them.

If the signal from the decoy aircraft is stronger than the signal from the target aircraft, the real-face radar will misjudge the angle and track the decoy aircraft. In many cases, real-face radar not only does not detect that it is being jammed, but even if it does, it
If the decoy aircraft is sufficiently far away from the target aircraft, it will not be able to reacquire the real target aircraft because the target aircraft is out of the main detection beam.

If the speed and position of the decoy aircraft can be controlled, the decoy aircraft can be maneuvered back into the main beam for effective jamming again.

If the decoy aircraft interferes with multiple search signals from multiple directions, it is not possible to keep the decoy aircraft in the main beam of all the search signals.

If the decoy aircraft becomes uncontrollable, the target aircraft will immediately escape out of the main beam. In this state, the real-face radar can reacquire the target aircraft. However, the decoy aircraft continues to look like a real target aircraft to real radar, and continues to attract the enemy's defenses. The enemy has no way of knowing that the decoy aircraft is not the true target aircraft, and for the maximum amount of time,
The detection range and Doppler are used to control the defense force to be directed towards the decoy aircraft. Another option for decoys outside the main beam would be sightlobe jammers.

In a preferred version of the invention, the decoy machine (16) comprises a power battery;
It consists of an aerodynamic aircraft with a diameter of several tens of millimeters to several hundreds of millimeters, equipped with an auxiliary propulsion device and having an appropriate weight to allow the decoy aircraft to take the required trajectory. The required trajectory is set so that the decoy aircraft can fly between the target aircraft and the real radar for as long as possible.

The decoy aircraft is designed to have enough propulsion to stay in the air between the target aircraft and the real radar for as long as possible, and the decoy aircraft is designed to stay in the main lobe for as long as possible. is then piloted and controlled by the target aircraft.

If the decoy aircraft (16) is a free-flying type that cannot be controlled and the real-face radar is in the direction of the target aircraft, the decoy aircraft will glide within the target aircraft's field of view for as long as possible.
Fired towards the front. If the search signal comes from behind, keep the decoy aircraft within sight for a long time without propelling it forward immediately.

The decoy machine (16) is configured to take on one or more, for example six, jammer modules. These jammer modules are approximately 50 x 100 mm (2
It is formed on a silicon chip approximately 4 inches thick, and has a thickness of 13 mm (1
2 inches) is installed in the aircraft as any jammer module card.

Omnidirectional transmitting and receiving antennas (50) and (80)
is constructed on the flange of the jammer module. The microwave components of the jammer module form a silicon monolithic hybrid circuit on one side, with the digital components, connections to the delay line, power supply, and main distribution board connected to the desired destination on the other side. ing.

The digitally controlled delay line (60) is a SAW type or bulk type delay line connected to a two-pole crossbar switch, mounted on the main distribution board, and connected to the module. The final transfer amplifier (68) and driver are of the best quality.

The multiple jammer modules are configured to operate independently under the control of the main unit. The jammer module is programmed by the main unit to cover a range of 750 to 1000 MHz in octave bands. Bandwidth is a block diagram that can be narrowed as dictated by signal bistability and strength requirements.

One jammer module in each decoy machine (16) includes a data link correlator (56) and a decoder (57).
) is provided. Data link signals are sent to other jammer modules via the main distribution board.

When the target aircraft is detected by the enemy search radar (10) and the enemy search signal evaluation device indicates that there is a possibility that an interceptor missile has been launched,
A decoy aircraft is launched from the target aircraft (14) or the chip.

The decoy aircraft is launched forward with sufficient propulsion to fly between the target aircraft and the search radar for the maximum amount of time.

As a result of jamming, enemy search radar (10) (12
) is directed closer to the decoy aircraft than the target aircraft (14). If the decoy aircraft is sufficiently far away from the target aircraft, the target aircraft is out of the detection range of the main beam. The enemy's acquisition radar detects the target aircraft (14) as a new target,
We can work towards that.

Unless the enemy search radar (10) is equipped with special equipment, there is no way to recognize that the decoy aircraft is not the true target aircraft. As a result, the semi-active missile heads towards the decoy aircraft (16) rather than the target aircraft (14). If it is detected that the target aircraft is re-detected by the enemy search radar (10),
Launch another decoy and repeat the process described above.

The decoy aircraft uses non-cooperative bistable detection and tracking equipment to track the missile and reverse when the missile approaches. If the decoy aircraft (16) is maneuverable, it is maneuvered back into the main beam and repeats the process. Decoy aircraft are also useful for interfering with other search signals that are returning or being held so as to direct enemy defenses to valid targets in other areas. Other additional features include launching a parachute, deploying a directional antenna, and initiating jamming in sidelobe jamming mode.

The decoy aircraft (16) should be configured to simultaneously jam search and acquisition radars. In this case, even after the enemy search radar (10) has reacquired the target aircraft (14), there is an advantage that jamming against these radars can be continued.

It is also advantageous to use a decoy aircraft to generate a false target if the target aircraft (14) has overtaken the decoy aircraft (16) and cannot continue false jamming for much longer.

The advantages of the method of main lobe jamming are as follows.

(1) The output (transfer antenna gain) required for jamming the main lobe may be 1 Watt or less.

The components of the phased array antenna can be improved and applied to the transfer device of a decoy aircraft.

(2) The decoy antenna does not require gain.

(3) Currently, no existing or future radar technology is contemplated that could counter this type of jamming. Therefore, this type of jamming is less sensitive to up-to-date intelligence data on enemy radar or missile systems.

(4) This type of decoy device is extremely inexpensive.

(a) In this example, the entire module is approximately 50×10
It is constructed on a 0 mm (2 x 4 inch) silicon monolithic hybrid substrate. The bandwidth of a single module can cover the applied technology and search signal strength.

(b) The decoy's body, propulsion device, battery, and power source are extremely inexpensive.

Each part (22) (24) shown in the second diagram showing an embodiment of the present invention.
) and (34) are AS in various data processing devices.
It is similar to that used in PJ systems, or AJQ-126 systems, and in addition to their normal functions, it can be programmed to calculate the required delay Ds, Doppler displacement Dp, and distance C. be.

Calculated values are used to transfer data in digital format.
Uses standard digital code system.

The variable delay line correlator (22) is a MIPS Model 112 or Model 119 manufactured by Hoitatsu Riki Tasker Systems, Chatworth, California, USA.
Alternatively, the "Multi-Contact SAW Delay Line" manufactured by Anderman Laboratories, Bloomfield, Conn., may be used. Data link correlator (3
6) is also a product of Anderman Laboratory Co., Ltd.
Programmable SAW correlator PSC-120-30
-4J may be used. A phased array transfer antenna is
An rHB phased array antenna manufactured by General Electric Co., Tucica, New York may be used.

All other parts are standard.

The components in the electronic system shown in Figure 3 are standard in the art. For example, data link
The correlator (56) is a product of Unterman Laboratory, “Programmable SAW Correlator PSC-12.
It can be the same as 0-4J, and the data link decoder (
57) and the SAW delay line may be an Anderman Laboratories "Multi-Contact SAW Delay Line" assembled with a custom two-pole crossbar switch formed as a custom silicon chip.

The various parts mentioned above are one silicon monolithic
It is formed on the hybrid element.

The above description is only one example of the present invention, and the present invention can be widely applied as shown in the modified examples described below.

Toroid Manrobe Jamming Mode In this mode of operation, the jammer is attached to a remotely controlled aircraft at the same speed as the target aircraft. While in contact with the search radar, the decoy device
Fly in a very irregular formation with respect to the target aircraft, within the main beam, at a position closer to the detection range of the enemy search radar than the target aircraft, and away from the target aircraft horizontally or vertically.
Shows a different angle from the target aircraft to the enemy search radar.

During contact with a search radar and an enemy missile, the strength of the jamming signal is varied to change the apparent angle and cause the missile to miss both the target aircraft and the decoy. It is important to conceal the structure of the remote control aircraft, thereby making it difficult for detection radars to track the decoy.

Other modes of operation are similar to the main lobe jamming described above. As a decoy device, a cruise missile with its warhead removed or other appropriate remote control aircraft may be used, and
A large number of slave jamming modules may be equipped, depending on the need to process anticipated detection signals. In this case, the output of the jammer module is set to 25
Amplify with a 0 watt CW amplifier. This gives the stop device the ability to conceal the target aircraft and, if necessary,
It will operate as a sidelobe jammer that interferes with the sidelobe angle of enemy search radars.

Sidelobe Jamming Mode The sidelobe jamming mode is similar to the mainlobe jamming mode, but differs in that it uses additional power and antenna gain to handle the sidelobes of the search radar. . The effect on search radars is that angle measurements are more likely to be misinterpreted by the obstructed enemy. As a result, the enemy search radar will misidentify the angle information of the range of the target aircraft and the Doppler amount at any angle.

One type of sidelobe jammer is the aforementioned toroid cruise missile, which can be used as either a mainlobe jammer or a sidelobe jammer. Another useful type is to install a jammer module on a ballistic missile such as the 5-inch Mark 71-1.

A parachute or balloon may be deployed near the enemy search radar. In this case, 250 watts CW
Use an amplifier or point the radar at a directional antenna with a strong gain that can overwhelm the radar's sidelobe suppression.

Enemies can use home-on-jam technology to sight lobe
In order to try to shoot down the jammers, it is preferable to use two sidelobe jammers against one search radar. The transmission intensity of the two decoy aircraft is made to resonate with the transmission frequency of the target tracking missile, and the mutual phase is set to 180 degrees.
If the angle calculation of the missile is varied by setting the angle to 100 degrees, the enemy's missile will not hit either jammer.

Stand-in Jammer Side Jammer is close to the enemy search radar ((within 3 km)
When deployed, there is no need to use additional CW amplifiers or antenna gain, and the decoy aircraft can be used in stand-in mode.

In this mode, the decoy aircraft detects only nearby enemy detection radars.
Interferes with all target aircraft within its detection range.

Standoff Jamming Standoff jamming uses uncomplicated search signals and
Pulse-to-pulse coding is a technique that can only be used if the pulse period can be predicted.

With many types of radars currently in existence, the use of standoff jamming for uncomplicated search signals is desirable as a means of reducing the operational burden of mainlobe and sidelobe jammers. .

The standoff jammer is as follows.

(1) Located on a separate aircraft, balloon, or remote control aircraft that remains behind the main operation by Shinrio.

(2) Only if the search signal does not use deceptive random pulse coding or the pulse train is delayed appropriately to confuse the search radar.

(3) Use a phased array antenna to fire a beam for each search signal and use approximately 250 watts CW as the forwarding power. This will interfere with the side lobes of the enemy search radar.

(4) The same system can be used for the mainlobe jammer and the sidelobe jammer, except for the repetition period of the subsequent pulse to be evaluated and the correction of the time uncertainty of the return pulse.

(5) A phased array antenna of sufficient size can be used to effectively counter search signals, retreat decoy aircraft to relatively safe locations, and protect large numbers of aircraft.

(6) Many different operating scenarios are possible, such as:

(a) A standoff jammer is used to jam all uncomplicated search signals, and a main lobe jammer is used for complex search signals.

(b) for both the target aircraft or the aircraft at a distant location;
It can be disguised as much as possible.

Ship Jammer The operation of the ship defense jammer is exactly the same as the aircraft defense described above. Since ships are large targets, directional antennas should be used and the transmitted power should be increased to 250 watts CW if possible.

The main unit is similar, if not identical, to the one described above. On the other hand, the decoy device must be made somewhat larger along with the directional antenna to accommodate the increase in transfer power.

Multiple remote control aircraft, such as the Albatross, are deployed around one or several ships to form a directional antenna. If you want the array to have a transfer function,
If the array is a true array, the output of the transfer device should be 250 watts CW TWT.

Another possibility is to launch a decoy aircraft from a rocket and deploy it during an attack. When the decoy is in position, the balloon or parachute [-
Open it and deploy the directional antenna.

In all cases it is important to use the jammer in main lobe jamming mode. Another possibility is to mount the jammer on an unmanned vessel approximately 10 m (30 ft) in size and navigate away from the vessel and sufficiently close to the main beam of the search radar.

〔Effect of the invention〕

(1) Conceal the target aircraft from the enemy's search radar,
Alternatively, it can misidentify the location of a target aircraft and protect friendly aircraft from enemy attacks.

(2) Since it receives a signal from an enemy search radar and sends back a camouflaged signal in response, it is highly effective in concealing the target aircraft or falsifying its position.

(3) Since the decoy machine has a relatively simple configuration, it is inexpensive.

(4) Effective jamming can be performed even against recent highly complex enemy search radars.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the system of the present invention, Figures 2A and 2B are block diagrams of the electronic data processing system installed on the target aircraft, and Figure 3 is a block diagram of the electronic system installed on the decoy aircraft. This is a block diagram. (10) (12) Enemy search radar (14) Target aircraft (16) Decoy aircraft (20) Omnidirectional receiving antenna (22) Signal detection, confirmation, classification and priority determination circuit (
24) Signal analyzer (26) Multiple phased array transmitting/receiving antenna (28) Multiplex switch (30) Baseband amplifier (32) Variable delay line (34) Treatment determining unit (36) Data link correlator (38) Data link oscillator and Decoder (40) Data link amplifier (50) Receiving antenna (52) Mixer (53) Local oscillator (54) Baseband amplifier (56) Data link correlator (57) Data link decoder (58) Bandwidth and gain variable circuit (59) Doppler frequency synthesizer (60) Delay line (62) Doppler signal generator (64) Fundamental band amplification (66) Transfer signal mixer (
68) Radar signal band amplifier (80) Transfer antenna FIG, 2 FIG, 2△

Claims (12)

[Claims] (1) Radar jamming consisting of a target aircraft and a decoy aircraft
The system includes a search radar detection system installed on the target aircraft, a decoy signal transmission system installed on the decoy aircraft, a data link between the target aircraft and the decoy aircraft, and a communication system installed on the target aircraft that connects the target aircraft and the decoy aircraft. a signal analyzer capable of measuring the distance to the target aircraft, and a means for calculating the required signal delay amount and Doppler displacement amount to conceal the target aircraft, and transmitting the calculated signal to the decoy aircraft via the early data link. is mounted on the decoy aircraft, and when it outputs and transmits a radar pulse with the calculated delay amount and Doppler displacement amount under data link control, the pulse is matched to the time and frequency of the reflected signal from the target aircraft. an electronic countermeasure system comprising means for causing (2) Installed on the target aircraft, detects and analyzes enemy search signals,
An electronic countermeasure system that transmits a signal to control a radar signal from a decoy aircraft, the system comprising one receiving antenna and a plurality of transmitting antennas that receive one or a plurality of independent enemy search radar signals, and each received signal. Measure and calculate the distance between the decoy aircraft and the target aircraft,
and the frequency difference (Df) and arrival time difference (D
means for measuring and calculating the amount of delay and Doppler displacement of the necessary radar signal sent from the decoy aircraft for each enemy search radar signal in order to conceal the reflected signal from the target aircraft; , providing the decoy with appropriate signals regarding the delay, Doppler shift, bandwidth, gain and center frequency of the signal to be emitted by the decoy, such that the pulses match both time and frequency with the target signal; an electronic countermeasure system comprising means for firing. (3) The main anti-radar system, which includes means for detecting and receiving radar signals from multiple enemy search radars, means for determining which enemy search radars should be jammed and their priorities, and installed for each enemy search radar. a signal analyzer that measures and calculates the distance between the decoy aircraft and the target aircraft and the amount of change in distance; a means for operating the decoy aircraft equipped with a jammer under the control of the signal analyzer; and a means installed in the signal analyzer. means for calculating the amount of displacement and delay that should be added to the jamming signal in order to match the time and frequency with the reflected signal in order to hide the reflected signal from the target aircraft; an electronic countermeasure system comprising: means for transmitting to the electronic countermeasures system; (4) A radar jamming system for a decoy aircraft installed on a decoy aircraft that receives control signals from a target aircraft, which includes a data link decoder, a variable delay line, a Doppler frequency synthesizer, and a delay required for the radar signal. means for transmitting a combination of the amount and the Doppler displacement amount from the decoy machine, the means being controlled by a data link decoder,
An electronic countermeasure system in which a delay amount and a Doppler displacement amount are determined so that a transmitted signal matches a reflected signal from a target aircraft. (5) The electronic countermeasure system according to claim (1), wherein the signal emitted from the decoy aircraft is made to match the time and frequency of the reflected signal from the target aircraft captured by the enemy search radar to conceal the target aircraft. . (6) a main anti-radar system, means for detecting and receiving radar signals from a plurality of enemy search radars;
Equipped with a means for determining the enemy search radar to be jammed and its priority order, and a signal analysis device installed for each enemy search radar, each signal analysis device measures and calculates the following values: (a) decoy Distance between the aircraft and the target aircraft (B) (b) Amount of delay (Ddo) as the time difference between the directly incident signal and the signal transferred from the decoy aircraft (c) Distance between the decoy aircraft and the target aircraft (dB/dt) (d) Difference in frequency between the directly incident signal and the signal transferred from the decoy device (
Df) Furthermore, a means for transmitting the calculated Doppler displacement and delay amount to the decoy aircraft, and a means for transmitting the received search radar signal mounted on the decoy aircraft with the same frequency and code (if any), and and a means for inserting the calculated Doppler displacement amount and delay amount into the enemy search radar signal and retransmit it, and the retransmission radar signal emitted from the decoy aircraft is reflected by the target aircraft as the enemy search radar signal, phase, and code. An electronic countermeasure system in which the signal strength from the decoy aircraft is greater than the reflected signal from the target aircraft, and the signals are emitted from different angular directions. (7) An electronic countermeasure system installed on a target aircraft that detects and analyzes search radar signals and controls the radar signals using a decoy device, which receives one or multiple separate search radar signals. (a) means for calculating the following values for each received signal; time difference (Ddo) (b) Doppler amount of signal from decoy aircraft to target aircraft (dB/dt) (c
) The angle between the decoy aircraft and the enemy search radar as seen from the target aircraft (∠
A) (d) Frequency difference (Df) between the signal directly incident on the target aircraft from the enemy search radar and the signal transferred from the decoy aircraft Calculate the values of Dp, Ds, and C using the following formulas. Means, Ds=2B-2Ddo Dp=dB/dt-Df C=Ddo(2B-Ddo)/[2B(cosA-1)
+2Ddo] However, Dp: Doppler displacement amount given to the jammer signal so that the signal from the gunner from the decoy aircraft matches the Doppler amount of the target aircraft captured by the enemy search radar Ds: The amount of Doppler displacement given to the jammer signal Amount of delay C given to the signal emitted from the jammer of the decoy aircraft so as to conceal it: The distance between the target aircraft and the enemy search radar, and the time and frequency of the transmitted signal from the decoy aircraft are compared with the reflected signal of the target aircraft. Electronic countermeasure systems made to match. (8) The amount of delay given to the signal transferred from the decoy device is Ds
7. The electronic countermeasure system according to claim 6, wherein the reflected signal from the target aircraft received by the enemy search radar is concealed by delaying it by a Ds value calculated by =2B-2Ddo. (9) The amount of Doppler displacement given to the signal transferred from the decoy aircraft is changed by the Dp value calculated by Dp = dB/dt-Df so that it matches the Doppler amount of the target aircraft received by the enemy search radar. The electronic countermeasure system according to claim (6). (10) The distance C between the target aircraft and the enemy search radar is C=Dd
o(2B-Ddo)/[2B(cosA-1)+2Dd
o] The electronic countermeasure system according to claim 6, wherein A is calculated based on the angle formed by the enemy search radar and the decoy aircraft as seen from the target aircraft. (11) Delay amount Ds and Doppler displacement amount Dp, Ds=2
The electronic countermeasure system according to claim 6, wherein the calculation is performed as follows: B-2Ddo Dp=dB/dt-Df. (12) A means for continuously monitoring the radar signal retransmitted from the decoy aircraft, including means for continuously measuring Ds and Ddf and calculating the difference value, and It is equipped with means for calculating the Doppler displacement amount (Ds) and delay time (Ddf) of the radar signal transmitted from the decoy aircraft with respect to the radar signal, so that the time and frequency match the reflected signal from the target aircraft, 7. The electronic countermeasure system according to claim 6, wherein the signal from the target aircraft is concealed by transmitting a signal that causes a misunderstanding of the angle from the decoy aircraft.