A radar decoy decoying effect calculation method

Abstract

The application discloses a radar decoy decoying effect calculation method, which comprises the following steps: firstly, a counter-radiation seeker is installed on a flight platform to carry out a hanging flight test, a ground radar and multiple decoys form a multi-point source radar decoying mode, the working parameters of the counter-radiation seeker, the radar and the decoys, and the position information of the flight platform are recorded, and the probabilities of the counter-radiation seeker tracking each decoy are counted; then, under the condition that the counter-radiation seeker can correctly identify the radar and the decoys, the miss distance of switching from tracking a certain decoy to tracking the radar is calculated, and the hit probability of a counter-radiation missile is calculated according to the miss distance; then, under the condition that the counter-radiation seeker cannot correctly identify the radar and the decoys, the miss distance under the condition is calculated, and the hit probability of the counter-radiation missile is calculated according to the miss distance; finally, the integrated hit probability of the counter-radiation missile is calculated by comprehensively considering the two conditions that the counter-radiation seeker can correctly identify and cannot identify the radar and the decoys. The radar decoy decoying effect can be more accurately evaluated.

Description

Technical Field

[0001] This invention belongs to the field of signal and information processing technology, and in particular relates to a method for calculating the deflection effect of radar decoys. Background Technology

[0002] Radar decoys are a crucial means of countering anti-radiation missiles. By strategically deploying radar decoys near radar systems and appropriately configuring their operating parameters, layout, and relative timing with the radar, a spatial deception beam is created. This makes it difficult for anti-radiation seekers to distinguish between the radar and the decoy, causing them to deviate from the radar's tracking direction, thereby improving the radar's battlefield survivability. Evaluating the radar deflection effect is a vital method for assessing the performance of radar decoys against anti-radiation missiles and provides significant guidance for the construction, layout, and configuration of radar decoys.

[0003] Currently, the evaluation of radar decoy deflection effectiveness mainly employs methods such as live-fire flight, simulation calculation, and flight-mounted tests. Live-fire flight has the significant advantage of direct effectiveness; however, it is costly and yields limited samples. Simulation calculation is cost-effective and yields a large sample size, but suffers from issues such as idealized calculation models and incomplete consideration of error factors. Flight-mounted tests, using UAVs, airships, or other flight platforms equipped with anti-radiation seekers, are conducted in conjunction with ground-based radar decoy systems. This method combines the advantages of live-fire flight and simulation calculation, providing a richer sample size at a relatively low cost, making it a commonly used approach. In evaluating the deflection effectiveness of radar decoys based on flight-mounted tests, current research largely relies on the assumption that the radar decoy and radar signal arrive at the anti-radiation seeker simultaneously, generating a synthetic interference signal. This is not entirely consistent with the actual deflection patterns used by existing radar decoys, thus the deflection effectiveness evaluation methods are not entirely applicable to real-world situations. Summary of the Invention

[0004] To address the problem that the assumption in existing calculation methods that the radar decoy and radar signal arrive at the anti-radiation seeker simultaneously to generate a synthetic interference signal does not fully match reality, the present invention aims to provide a method for calculating the deflection effect of radar decoys. This method addresses the evaluation of the deflection effect of radar decoys in anti-radiation seeker flight tests. It uses the probability of a multi-point source radar decoy deflecting an anti-radiation missile as an evaluation index. By statistically analyzing the tracking probability of different decoys during different operating periods of the anti-radiation missile, and combining this with the analysis of the hit probability under different conditions such as whether the seeker can identify the target, the overall deflection probability of the radar decoy is finally given.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A method for calculating the deflection effect of radar decoys includes the following steps:

[0007] S1. The anti-radiation seeker was installed on the flight platform for flight test. The ground radar and multiple decoys formed a multi-point source radar deflection mode. The working parameters of the anti-radiation seeker, radar, and decoys, as well as the position information of the flight platform, were recorded.

[0008] S2. Using the operating parameters of the anti-radiation seeker, radar, and decoys recorded in step S1, calculate the probability P of the anti-radiation seeker tracking each decoy. i ;

[0009] S3. Under the condition that the anti-radiation seeker can just distinguish between the radar and the decoy, and the anti-radiation seeker can correctly identify the radar and the decoy, calculate the miss distance r when switching from initially tracking the i-th decoy to tracking the radar. i Then, based on the off-target amount r i Calculate the corresponding deflection probability, i.e., the anti-radiation missile hit probability P. h (r i );

[0010] S4. At the critical moment when the anti-radiation seeker can just distinguish the radar and each decoy, but fails to correctly identify the radar and decoys, calculate the miss distance r under this condition. d According to the off-target amount r d Calculate the hit probability P of the anti-radiation missile when it switches from initially tracking the i-th decoy to tracking the radar, provided the anti-radiation seeker fails to correctly identify the radar and decoy. hD ;

[0011] S5. Calculate the overall hit probability P of the anti-radiation missile under two scenarios: the seeker can correctly identify the radar and the decoy. d ,

[0012]

[0013] In the formula, N is the number of baits;

[0014] P r This increases the probability of the anti-radiation seeker correctly identifying radar and decoys.

[0015] Furthermore, in step S1 above, the flight platform includes, but is not limited to, drones and airships.

[0016] Furthermore, in step S2 above, the probability P of the seeker tracking each decoy is calculated according to formula (2). i ,

[0017]

[0018] In the formula, T represents the time period from the start of the flight platform's formal simulation of anti-radiation missile flight during the flight test to the critical moment when the anti-radiation seeker precisely distinguishes the radar and the decoy; ti The cumulative time for the anti-radiation seeker to track the i-th decoy. N is the number of baits; ∑P i =1.

[0019] Furthermore, the multi-point source radar deflection mode composed of ground radar and multiple decoys adopts the leading edge alternation mode, that is, different decoy signals alternately lead the radar signal to completely surround the radar signal in terms of transmission time; at the same time, the anti-radiation seeker adopts the leading edge tracking mode, alternately tracking different decoys.

[0020] Furthermore, in step S3 above, under the condition that the anti-radiation seeker can correctly identify the radar and the decoy, based on the recorded flight platform, radar and decoy position information, and the geometric relationship between the seeker, radar and decoy at the critical moment when the anti-radiation seeker can just distinguish the radar and each decoy from the angle, the miss distance r from the initial tracking of the i-th decoy to tracking the radar is calculated according to formula (3). i ;

[0021]

[0022] In the formula, L is the maximum distance between the decoy and the radar;

[0023] R a Let be the distance from the anti-radiation seeker to the i-th decoy;

[0024] R o This refers to the distance from the anti-radiation seeker to the radar.

[0025] φ is the turning angle of the anti-radiation seeker as it maneuvers from tracking the i-th decoy to tracking the radar.

[0026] β is the angle between the line connecting the anti-radiation seeker to the i-th decoy and the line connecting the radar to the i-th decoy;

[0027] V m This refers to the actual flight speed of the anti-radiation missile.

[0028] mg is the maximum overload of the anti-radiation missile, and g is the acceleration due to gravity.

[0029] Furthermore, in step S3 above, based on the calculated miss distance r... i The corresponding deflection probability, i.e., the anti-radiation missile hit probability P, is calculated according to formula (4). h (r i ),

[0030]

[0031] In the formula, R e The equivalent radius of the target;

[0032] σ represents the variance of the anti-radiation missile's dispersion pattern on the ground;

[0033] I n (·) represents the nth-order modified Bessel function of the first kind.

[0034] Furthermore, in step S4 above, when the anti-radiation seeker is just able to distinguish between the radar and the decoy, if the anti-radiation seeker fails to correctly identify the radar and the decoy, the tracking direction of the anti-radiation seeker will alternate between multiple decoys, eventually hitting the center of gravity of the decoy array. The miss distance r under this condition is calculated according to formula (8). d ,

[0035]

[0036] In the formula, l is the side length of the radar decoy array arranged in an equilateral triangle.

[0037] Furthermore, in step S4 above, based on the calculated miss distance r... d The probability of a hit, P, under the condition that the missile fails to correctly identify the seeker and the decoy is calculated according to formula (9). hD ,

[0038]

[0039] In the formula, R e The equivalent radius of the target;

[0040] σ represents the variance of the anti-radiation missile's dispersion pattern on the ground;

[0041] I n (·) represents the nth-order modified Bessel function of the first kind.

[0042] Due to the adoption of the technical solution described above, the present invention has the following advantages:

[0043] This method for calculating the deflection effect of radar decoys establishes a probability calculation method for radar decoy deflection. It comprehensively considers the tracking and identification processes of the anti-radiation seeker during different operating periods, enabling a more accurate assessment of the deflection effect of radar decoys. It fully considers the deflection effects of different radar decoys on the anti-radiation seeker, making it more consistent with actual equipment usage. It overcomes the problem that the traditional calculation method's assumption of simultaneous arrival of the radar decoy and radar signal at the anti-radiation seeker to generate a synthetic interference signal does not fully match reality. The calculation process does not require complex computations and has low computational intensity, making it well-suited for engineering practice and applicable to air defense early warning radars, fire control guidance radars, and anti-radiation missiles. Attached Figure Description

[0044] Figure 1 This is a flowchart of the radar decoy deflection effect calculation method of the present invention;

[0045] Figure 2 This is a flight test situation diagram. Detailed Implementation

[0046] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] like Figure 1 As shown, a method for calculating the deflection effect of a radar decoy includes the following steps:

[0048] Step 1: The anti-radiation seeker is mounted on a flight platform for a flight test. The ground radar and multiple decoys form a multi-point source radar deflection mode. The operating parameters of the anti-radiation seeker, radar, and decoys, as well as the position information of the flight platform, are recorded. The flight platform includes, but is not limited to, UAVs and airships.

[0049] Step 2: Based on the operating parameters of the anti-radiation seeker, radar, and decoys recorded in step S1, calculate the probability P of the seeker tracking each decoy according to formula (2). i ,

[0050]

[0051] In the formula, T is the time period from the start of the flight platform's formal simulation of anti-radiation missile flight during the flight test to the critical moment when the anti-radiation seeker just distinguishes the radar and the decoy.

[0052] t i The cumulative time for the anti-radiation seeker to track the i-th decoy. N is the number of baits; ∑P i =1;

[0053] The multi-point source radar deflection mode, consisting of ground radar and multiple decoys, adopts an alternating leading edge mode, in which different decoy signals alternately lead the radar signal, thereby completely surrounding the radar signal in terms of transmission time; at the same time, the anti-radiation seeker adopts a leading edge tracking mode, alternately tracking different decoys.

[0054] Step 3: Under the condition that the anti-radiation seeker can correctly identify the radar and the decoy, based on the recorded flight platform, radar and decoy position information, and the geometric relationship between the seeker, radar and decoy at the critical moment when the anti-radiation seeker can just distinguish the radar and each decoy from the angle, calculate the miss distance r from the initial tracking of the i-th decoy to tracking the radar according to formula (3). i ;

[0055]

[0056] In the formula, L is the maximum distance between the decoy and the radar;

[0057] Ra Let be the distance from the anti-radiation seeker to the i-th decoy;

[0058] R o This refers to the distance from the anti-radiation seeker to the radar.

[0059] φ is the turning angle of the anti-radiation seeker as it maneuvers from tracking the i-th decoy to tracking the radar.

[0060] β is the angle between the line connecting the anti-radiation seeker to the i-th decoy and the line connecting the radar to the i-th decoy;

[0061] V m This refers to the actual flight speed of the anti-radiation missile.

[0062] mg is the maximum overload of the anti-radiation missile, and g is the acceleration due to gravity.

[0063] Step 4: Based on the off-target distance r calculated in Step 3 i The corresponding deflection probability, i.e., the anti-radiation missile hit probability P, is calculated according to formula (4). h (r i ),

[0064]

[0065] In the formula, R e The equivalent radius of the target;

[0066] σ represents the variance of the anti-radiation missile's dispersion pattern on the ground;

[0067] I n (·) represents the nth-order modified Bessel function of the first kind; the preferred value of n is 5 or 6;

[0068] The derivation of the above formula (4) is as follows:

[0069] Using the hit probability P h (r i The calculation form is as follows:

[0070]

[0071] In the formula, f(x,y) represents the dispersion pattern of the anti-radiation missile in a plane rectangular coordinate system, and D represents the geometric range of the target;

[0072] The dispersion pattern of anti-radiation missiles with a Gaussian distribution on the ground, namely...

[0073]

[0074] Where (x0, y0) is the dispersion center, i.e., the point of impact; the distance between the anti-radiation missile's point of impact and the target center is the final miss distance, i.e.

[0075] Variance σ and Angular Measurement Error σ of Anti-radiation Seeker α Finally, the target distance R when there is no angle measurement information p And the hit error σ of the anti-radiation missile itself. k Related, that is

[0076]

[0077] In the formula, R p This refers to the missile-target distance at the moment the radar is shut down, or the missile-target distance when the anti-radiation seeker finally cuts off guidance information; typically σ α R p >>σ k ;

[0078] Using a radius of R c The target shape is circular, and it is an anti-radiation missile equipped with a proximity fuse. The effective range of the proximity fuse is equal to the kill radius R of the anti-radiation missile. k A proximity fuse is equivalent to increasing the size of the target, meaning the target's equivalent radius is R. e =R c +R k R k >>R c R e ≈R k ;

[0079] Step 5: At the critical moment when the anti-radiation seeker can just distinguish the radar and each decoy, if the anti-radiation seeker fails to correctly identify the radar and decoys, the tracking direction of the anti-radiation seeker will alternate between multiple decoys, eventually hitting the center of gravity of the decoy array. Calculate the miss distance r under this condition according to formula (8). d ,

[0080]

[0081] In the formula, l is the side length of the radar decoy array arranged in an equilateral triangle;

[0082] Step 6: Based on the off-target distance r calculated in step S5 d The hit probability P under the condition that the anti-radiation seeker fails to correctly identify the radar and decoy is calculated according to formula (9). hD ;

[0083]

[0084] In the formula, R e The equivalent radius of the target;

[0085] σ represents the variance of the anti-radiation missile's dispersion pattern on the ground;

[0086] I n (·) represents the nth-order modified Bessel function of the first kind; the preferred value of n is 5 to 6;

[0087] Step 7: Calculate the overall hit probability P of the anti-radiation missile in both cases where the seeker can correctly identify the radar and the decoy. d ,

[0088]

[0089] In the formula, N is the number of baits;

[0090] P h (r i ) represents the hit probability under the condition that the tracking of the i-th decoy is switched to tracking the radar;

[0091] P r To increase the probability of the anti-radiation seeker correctly identifying radar and decoys;

[0092] P hD The probability of radar hit when tracking the center of gravity of a decoy.

[0093] The implementation of the technical solution of the present invention will be described in detail through the following embodiments.

[0094] This embodiment is a simulation example, depicting an anti-radiation missile attack scenario as follows: Figure 2 As shown, both the decoys and the radar are located in the Z=0 plane. Decoy A is located at (1000,0,0), decoy B at (853,170,0), and decoy C at (853,-170,0). The radar is located at the origin (0,0,0). The side length of the decoy array is 170, and all coordinate units are in meters. The equivalent radiated power of the decoys is 3 dB greater than the average sidelobe equivalent radiated power of the radar. The decoys and the radar have the same signal waveform parameters: a center frequency of 10 GHz, a signal bandwidth of 2 MHz, a pulse width of 30 μs, a modulation pattern of linear frequency modulation, and a pulse repetition rate of 500 Hz. Under external guidance, the decoy array adopts an alternating leading-edge operating mode with an alternation frequency of 10 Hz. The anti-radiation missile has a flight speed of 1250 m / s, a maximum overload of 10 g, and a kill radius of 35 m. The anti-radiation seeker adopts a leading-edge tracking mode with a tracking data rate of 50Hz. It has the ability to distinguish radar and decoys, such as polarization identification and intra-pulse strong signal detection. The resolution angle is 10°, the angle measurement accuracy is 0.5°, the identification probability is 0.95, and the target distance when the guidance information is cut off is 600m.

[0095] During the anti-radiation missile's flight towards the radar, when the seeker fails to distinguish between the radar and the decoy, its altitude gradually decreases in the Y=0 plane as it approaches the radar. Since the radar is furthest from decoy A, the seeker will distinguish between the radar and decoy A first. Assuming the missile reaches a point where it can just distinguish between the radar and decoy A at a 60° angle to the horizontal, the missile's coordinates at this critical moment are (2706, 0, 4687). After the critical moment, the missile's motion falls into two categories: 1) If the seeker successfully identifies the radar signal, the missile will switch from tracking the decoy to tracking the radar; the hit probability calculation method for switching from tracking decoy B or C to tracking the missile is similar; 2) If the seeker fails to identify the radar signal, it will continue to alternately track decoys A to C. While the seeker cannot distinguish decoys A to C by angle, the seeker's tracking direction remains unchanged; considering the missile's high speed and the equidistant distance between each pair of decoys, the time for the seeker to distinguish decoys A to C one by one can be ignored, simplifying it to the seeker simultaneously distinguishing decoys A to C; after distinguishing the three decoys, the seeker will alternately swing between decoys A to C, eventually hitting the center of gravity of the decoy array.

[0096] Reference Figure 1 A method for calculating the deflection effect of radar decoys, specifically including the following steps:

[0097] Step 1: The anti-radiation seeker is installed on the flight platform for flight testing, according to... Figure 2 The ground radar and three decoys form a multi-point source radar deflection mode to record the operating parameters of the anti-radiation seeker, radar, and decoys, as well as the flight platform's position information.

[0098] Step 2: Analyze the recorded operating parameters of the anti-radiation seeker, radar, and decoys. Since the decoy signals alternately lead the radar signals, and the alternation period is roughly equivalent to the seeker's reaction time, the seeker will track one of the decoys A to C with equal probability just before it can distinguish the radar and each decoy. Calculate the probability P of the seeker tracking each decoy using the following formula. i ,

[0099]

[0100] In the formula, T represents the time interval from the start of the flight platform's formal simulation of anti-radiation missile flight during the flight test to the critical moment when the anti-radiation seeker precisely distinguishes the radar and the decoy; t i The cumulative time for the anti-radiation missile to track the i-th decoy. N is 3; ∑P i =1;

[0101] Step 3: Under the condition that the seeker can correctly identify the radar and decoys, based on the recorded flight platform, radar, and decoy position information, calculate the miss distance r when the seeker can just distinguish the radar and each decoy from the angle of the seeker. Calculate the miss distance r when the seeker switches from initially tracking decoys A to C to tracking the radar. A =27.7m, r B =49.5m, r C =49.5m;

[0102] Step 4: Based on the off-target amount r obtained in step S3 A r B r C Calculate the corresponding deflection probability, i.e., the anti-radiation missile hit probability, which is P. h (r A ) = 0.905, P h (r B ) = 0.002, P h (r C ) = 0.002;

[0103] The variance σ of the anti-radiation missile dispersion pattern on the ground is given by σ = σ α R p =0.52m, the equivalent radius R of the target e =35m;

[0104] Step 5: At the critical moment when the seeker can just distinguish the radar and each decoy, but the seeker fails to correctly identify the radar and decoys, calculate the miss distance r under this condition according to the following formula. d ,

[0105]

[0106] Step 6: The off-target distance r calculated from step S5 d The hit probability P under the condition that the anti-radiation seeker fails to correctly identify the radar and decoy is calculated according to formula (9). hD =0;

[0107] Step 7: Considering both scenarios where the seeker can correctly identify the radar and the decoy, and the known probability P of the seeker's identification,... r Given a value of 0.95, calculate the overall hit probability P of the seeker. d ,

[0108]

[0109] The above description is only a preferred embodiment of the present invention and not a limitation thereof. Any equivalent changes and modifications made in accordance with the scope of the present invention without departing from the spirit and scope of the present invention shall be within the scope of patent protection of the present invention.

Claims

1. A method for calculating the deflection effect of radar decoys, characterized in that: It includes the following steps: S1. The anti-radiation seeker is mounted on a flight platform for flight testing. Ground radar and multiple decoys form a multi-point source radar deflection mode. The operating parameters of the anti-radiation seeker, radar, and decoys, as well as the flight platform's position information, are recorded. The multi-point source radar deflection mode adopts an alternating leading-edge mode, that is, different decoy signals alternately lead the radar signal to completely surround the radar signal in terms of launch time. At the same time, the anti-radiation seeker adopts a leading-edge tracking mode, alternately tracking different decoys. S2. Using the operating parameters of the anti-radiation seeker, radar, and decoys recorded in step S1, calculate the probability that the anti-radiation seeker will track each decoy. ; S3. Under the condition that the anti-radiation seeker can correctly identify the radar and decoys, based on the recorded flight platform, radar and decoy position information, and the critical moment when the anti-radiation seeker can just distinguish the radar and each decoy, the geometric relationship between the seeker, radar and decoys is calculated according to formula (3) from the initial tracking first step. Miss range of a decoy-to-track radar ; （1） In the formula, This represents the maximum distance between the decoy and the radar. For the anti-radiation seeker to the first The distance of the bait; This refers to the distance from the anti-radiation seeker to the radar. For the anti-radiation seeker, the tracking head is the first The angle of maneuver correction for the decoy tracking radar; For the anti-radiation seeker to the first The lines connecting the decoys to the radar are linked to the first... The angle between the lines connecting the baits; This refers to the actual flight speed of the anti-radiation missile. For the maximum overload of the anti-radiation missile, It is the acceleration due to gravity; Based on the calculated miss distance The corresponding deflection probability, i.e. the anti-radiation missile hit probability, is calculated according to formula (4). , （2） In the formula, The equivalent radius of the target; The variance of the dispersion pattern of anti-radiation missiles on the ground; for The first-order modified Bessel function of the order; S4. When the anti-radiation seeker can just distinguish between the radar and the decoy, but fails to correctly identify the radar and the decoy, the tracking direction of the anti-radiation seeker will swing alternately between multiple decoys, eventually hitting the center of gravity of the decoy array. Calculate the miss distance under this condition according to formula (8). , （4） In the formula, This represents the maximum distance between the decoy and the radar. The side length of the radar decoy array arranged in an equilateral triangle; Based on the calculated miss distance The hit probability under the condition that the anti-radiation seeker fails to correctly identify the radar and decoy is calculated according to formula (9). , （9） In the formula, The equivalent radius of the target; The variance of the dispersion pattern of anti-radiation missiles on the ground; for The first-order modified Bessel function of the order; S5. The integrated seeker calculates the overall hit probability of the anti-radiation missile under two scenarios: when it can correctly identify the radar and when it fails to identify the decoy. , （3） In the formula, N is the number of baits; This increases the probability of the anti-radiation seeker correctly identifying radar and decoys.

2. The method for calculating the deflection effect of radar decoys according to claim 1, characterized in that: In step S1, the flight platform includes, but is not limited to, drones and airships.

3. The method for calculating the deflection effect of radar decoys according to claim 1, characterized in that: In step S2, the probability of the seeker tracking each decoy is calculated according to formula (2). , （4） In the formula, The time period from the start of the flight platform's formal simulation of anti-radiation missile flight during the flight test to the critical moment when the anti-radiation seeker just distinguishes the radar and the decoy; For anti-radiation seeker to track the first The cumulative time of each bait, , The quantity of bait; .

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