CN112859027B - Bait array interference effectiveness analysis method based on one-dimensional range profile - Google Patents
Bait array interference effectiveness analysis method based on one-dimensional range profile Download PDFInfo
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/411—Identification of targets based on measurements of radar reflectivity
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/36—Means for anti-jamming, e.g. ECCM, i.e. electronic counter-counter measures
Abstract
The invention belongs to the technical field of electronics and science, and discloses a method for analyzing interference effectiveness of a bait array based on a one-dimensional range profile. Establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one; performing shielding judgment on model surface elements in the irradiation range of the radar signal, recording and storing surface element serial numbers reflected on the propagation path, and recording surface element serial numbers reached by mutual reflection of the models; solving the electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional range profile of the target object; interference effectiveness evaluation is performed on the bait array in the actual sea state background by using the one-dimensional distance pair. The invention solves the problem of high-efficiency calculation of the existing one-dimensional range profile under the complex conditions of the ship target with the complex structure, the bait array and the rough sea surface.
Description
Technical Field
The invention belongs to the technical field of electronics and science, and particularly relates to a bait array interference efficiency analysis method based on a one-dimensional range profile.
Background
At present: in the radar detection field, mainly obtained target information is a high resolution range profile (High Resolution Range Profile, HRRP), a radar cross section (Radar Cross section), and a range rate or radial speed, azimuth, altitude, etc. The high-resolution range profile is a vector sum amplitude waveform projected on a radar line by target scattering point sub-echoes in each range bin, and is a broadband radar image. The original high-resolution range profile data is plural, so that not only can the very much target structure information be reflected, but also the advantages of high-speed processing, easiness in acquisition and the like can be realized, and the range profile data has very high degree of correlation in the field of automatic target identification and is applied to experiments in various research directions. The high-resolution broadband radar emits broadband signals with higher accuracy than narrowband signals, and imaging quality cannot be affected by bad weather, so that the application field is wider. The key point of the military radar is that the military radar can rapidly and efficiently identify enemy aircrafts, ships, submarines, underwater weapons, long-distance hitting weapons and the like in combat, so that the military radar can not be in a passive state in a battlefield, and the improvement of the identification rate and the identification speed is the improvement of the winning rate.
The radar corner reflector is a cavity structure composed of metal steel or coated metal materials. When electromagnetic waves irradiate the corner reflector, the characteristic of the structure of the corner reflector can generate a very large radar scattering cross section in the backward direction of the corner reflector, so that the radar guided weapon is wrongly judged, and the important military targets on the my side are protected. The radar corner reflector mainly achieves the purpose of invisible false indication by forming a virtual false target, for example, deceives an enemy detection radar, destroys a data processing system of the radar corner reflector, increases the time for surveying a target structure and realizing the purpose of invalidation of an enemy system finally. The radar corner reflector has the advantages of low cost, high cost performance, good interference effect, easy production equipment, omnibearing and the like, and plays an important role in electronic countermeasure, missile weapon attack and defense and other occasions.
In summary, the interference efficiency analysis of the bait array, the ship and the sea surface composite has the following significant disadvantages: for analysis of the bait array, reasonable analysis is mostly carried out based on radar scattering cross sections, but radar scattering cross sections fluctuate greatly along with angles, so that results are inaccurate, and error rate is large. Considering that under actual sea conditions, the composite surface area of the bait array, the ship target and the sea surface is larger, the data volume of the radar scattering section is larger, the radar scattering section is difficult to acquire, and the calculation efficiency is too low. And secondly, the result obtained by the RCS scattering calculation method based on the frequency domain is not comprehensive enough, the radar time domain echo cannot be truly simulated, and difficulty is brought to interference effectiveness evaluation under sea warfare live condition.
Through the above analysis, the problems and defects existing in the prior art are as follows:
(1) Most of the existing bait array analysis technologies are based on radar scattering cross section calculation, but under actual sea conditions, the bait array fluctuates along with sea surface fluctuation, RCS fluctuates along with angles to be larger, so that a result is inaccurate, and an error rate is larger.
(2) Under actual sea conditions, the composite surface area of the bait array, the ship target and the sea surface is large, the data volume of the calculated radar scattering section is large and difficult to acquire, the data processing requirement is too high, and the calculation efficiency is too low.
(3) The result obtained by the traditional RCS scattering calculation method based on the frequency domain is not comprehensive enough, radar time domain echo cannot be simulated truly, and difficulty is brought to interference efficiency evaluation under sea warfare live condition.
The difficulty of solving the problems and the defects is as follows: how to obtain a one-dimensional distance image compounded by a bait array, a ship target and a sea surface; how to evaluate the interference effectiveness of a bait array using one-dimensional distance pairs.
The meaning of solving the problems and the defects is as follows: under the sea surface background, the bait interference and the one-dimensional range profile of the ship target are rapidly acquired and calculated, the bait interference effect is evaluated, the use of the bait array in a sea battlefield is effectively promoted, and data support is provided for the design and use of subsequent sea warfare interferents.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention provides a bait array interference effectiveness analysis method based on a one-dimensional range profile.
The invention is realized in such a way, a method for analyzing the interference efficiency of a bait array based on a one-dimensional range profile, which comprises the following steps:
establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one;
performing shielding judgment on model surface elements in the irradiation range of the radar signal, recording and storing surface element serial numbers reflected on the propagation path, and recording surface element serial numbers reached by mutual reflection of the models;
solving the electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional distance image of the target object;
interference effectiveness evaluation is performed on the bait array in the actual sea state background by using the one-dimensional distance pair.
Further, the method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile comprises the following steps:
(1) Collecting a model diagram of the ship; front and top views of the lead-in model;
(2) Drawing main characteristic lines by using RHO software, and drawing the outline shape of the model; splitting the surface on the basis of the drawn characteristic curve, splitting the surface at the place with the trend mutation, establishing a curved surface according to the drawn line, and using a curved surface connection command to achieve the curvature continuity of the curved surface;
(3) Establishing a side surface of a ship for mirror image operation, establishing an upper bottom surface and a lower bottom surface, and deleting according to the need to obtain an internal empty groove structure of the ship;
(4) Exporting and storing the established ship model;
establishing an angle reflector model, carrying out icosahedron angle reflector modeling, wherein the angle reflector is established step by step based on the geometric model of a regular icosahedron, and the triangular emitter is a basic constituent unit thereof;
(1) Firstly, 12 vertexes are found out, 30 edges are formed by two pairs of vertexes, and a multi-convex polyhedron obtained by the frame is a regular icosahedron; establishing an O-XYZ rectangular coordinate system, and respectively establishing three auxiliary rectangles A on the XOY plane, the YOZ plane and the XOZ plane by taking the origin of coordinates as the center i B i C i D i I=1, 2,3, and the three rectangular aspect ratios need to be consistentGolden ratio:
these 12 points { A ] i ,B i ,C i ,D i I=1, 2, 3), namely twelve vertices of a positive 20-sided body;
(2) And respectively connecting each point with five points closest to the points to obtain 30 edges, and obtaining the base frame of the icosahedron. On the basis of the constructed regular icosahedron, adding a structure with a triangular surface, performing Boolean operation by using the regular icosahedron, and respectively taking each regular triangle surface as a base to subtract a regular triangular pyramid with an equal bottom surface and three edges perpendicular to each other inwards to obtain a geometric model of the regular icosahedron corner reflector;
establishing a simple rough sea surface model, and taking the sea surface wind direction influence into consideration according to a PM sea spectrum formula, wherein the PM sea spectrum expression formula is as follows:
wherein α=8.10×10 -3 Beta=0.74, k is the spatial wave number of the ocean wave, U 19.5 Is the wind speed at 19.5m above the sea surface; g 0 ＝9.81m/s 2 Gravitational acceleration;
introducing a Longuest-Higgins angle distribution function to simulate the sea surface, wherein the expression is:
wherein,
s in the above formula represents the concentration degree of the direction function, and the spatial wave number and wind speed U 19.5 Related to;indicating the wind direction;
for a two-dimensional sea surface, the direction spectrum can be written as a combination of a general spectrum function and a direction function, namely:
wherein ()' is an omnidirectional sea spectrum,is an angle distribution function;
through the formula, rough sea surface model programming is performed based on the Monte Carlo method, and sea surface models under different wind directions and wind speeds are constructed.
Further, the method for analyzing the interference efficiency of the bait array based on the one-dimensional range profile performs surface element subdivision, selects Delaunay triangulation technology, performs triangular subdivision on the established ship target model, the bait array model and the sea surface model thereof, obtains the index list of each triangle vertex, normal vector and central point of the outer envelope, and establishes a database, and the method specifically comprises the following steps:
(1) The three-dimensional Delaunay triangulation based on the Bowyer-Watson algorithm is mainly realized by a point-by-point insertion mode, and the implementation steps are as follows:
1) Constructing a super tetrahedron, including all scattered points, and placing the super tetrahedron into a tetrahedron linked list;
2) Sequentially inserting scattered points in the point set, finding out tetrahedrons with the inserted points in the tetrahedron linked list, deleting common edges affecting the tetrahedrons, connecting the inserted points with all vertexes affecting the tetrahedrons, and completing the insertion of one point in the Delaunay tetrahedron linked list;
3) Optimizing the locally newly formed tetrahedron according to an optimization criterion, and putting the formed tetrahedron into a tetrahedron linked list;
4) Circularly executing the step 2) until all the scattered points are inserted;
(2) After splitting, searching the outer envelope triangle of each region and the corresponding normal vector thereof, wherein the steps are as follows:
1) Judging that in the tetrahedron linked list, if one face is only referenced by one tetrahedron, the face is positioned on the boundary, and returning the serial numbers of the vertexes and the coordinates of each vertex which form the face;
2) The coordinates of the center points of the surfaces are calculated and correspondingly stored, and the calculation formula is as follows:
3) The triangular coordinate points are A (x) 1 ,y 1 ,z 1 )，B(x 2 ,y 2 ,z 2 )，C(x 3 ,y 3 ,z 3 ) The normal vector (a, b, c) of each face and its direction are calculated and stored, and the calculation formula is as follows:
normal vectorObeys the right-handed screw rule, all facing outwards.
Further, the method for analyzing the interference efficiency of the bait array based on the one-dimensional range profile performs shielding judgment on the model surface elements in the irradiation range of the radar signal, records and stores the surface element sequence numbers reflected on the propagation path, and records the surface element sequence numbers reached by the mutual reflection of the models, and specifically comprises the following steps:
(1) The production of the ray tube is intersected with the surface element, a triangle ray tube is used, and the triangle ray tube is overlapped with the triangle surface element, so that the ray tube does not emit and split when the first-order reflection of the target is carried out, and the main part of the scattering of the target is derived from the first-order reflection of the target;
distinguishing a dark area or a bright area of a surface element, wherein the conditions of self shielding and mutual shielding are needed;
And (3) performing self-shielding judgment: assume thatIs the propagation direction vector of the incident wave, < >>Is the external normal vector of the target patch by judging the vector +.>And->Is used for judging the included angle:
illuminating the area;
a shadow area;
compliance withThe surface element is the blocked target surface element;
and (5) performing mutual shielding judgment: mutual occlusion judgment is carried out on the surface element without self occlusion, and three vertexes of the surface element are respectively assumed to beThe initial coordinate of the vector is the origin, then any point on the triangle face is +.>The following equation is satisfied:
wherein u and v represent the weight influence of the vertex on a certain area, and when the weight influence of the vertex on a certain area meets that u is more than or equal to 0, v is more than or equal to 0, and u+v is less than or equal to 1, the point is describedInside the triangle bin;
the ray equation is:wherein (1)>Is the ray direction vector, d is the distance from any point on the ray to the starting point, then the intersection calculation of the ray and the triangle is equivalent to +.>Solving and substituting into an equation to obtain:
and (3) performing equivalent deformation:
by solving the equation, u, v and the distance d from the ray starting point to the intersection point can be obtained;
order theThen according to the cremmer rule:
wherein the method comprises the steps ofSolving u and v according to the formula, and determining whether the ray intersects the triangle surface element by calculating whether the u and v meet the judging condition; without solution If the condition is that the ray which is reversely sent from one surface element does not intersect with other surface elements, namely, mutual shielding does not occur; respectively carrying out primary incidence shielding judgment on the bait array, the ship target and the sea surface element, and storing the non-shielded surface element number to be an area which can be illuminated by rays;
(2) Selecting a time domain signal, and selecting a modulation Gaussian pulse as an excitation time domain signal;
standard modulated gaussian pulse time domain function:
wherein t is 0 Is the offset time, τ is the pulse width, f 0 The central frequency of the Fourier spectrum is Gao Simai dashes, and the bandwidth B and the central frequency f of an incident wave excitation signal are set according to the actual incident condition requirement 0 And τ=4/B;
the reflection of the tube at the illuminated surface element,representing the incident direction unit vector, & lt + & gt>Representing the reflection direction unit vector, ">The external normal vector of the illuminated face element can decompose the incident wave into two components of TE wave and TM wave with different rules, and its unit direction vector is respectively used +.>And->The reflected wave is similarly represented, and the unit direction vectors are respectively marked as +.>And->
For the followingAnd->The following relationship is satisfied:
after the field intensity of the illuminated surface element is obtained, the reflecting direction of the ray is obtained by combining the Snell theorem:
Selecting the gaussian pulse set as described above as the time domain signal G (t), the time domain incident wave can be expressed as:
wherein the method comprises the steps ofIs the coordinates of the target bin;
the electric field expression after the incident wave is scattered by the surface element for the first time is:
based on the coordinate position of the passing surface element and the ray direction vector, the time delay can be calculated, and the incident field of the incident wave reaching the following surface element after one-time scattering is obtained:
the reflected field intensity and the direction of the reflected rays at the illuminated surface element are obtained, and the reflected field intensity and the reflected direction are used as the secondary incident initial field intensity and the incident direction, so that the ray tracking among the surface elements can be performed for a plurality of times until the rays are emitted out of the target or the ray tracking times reach a set value.
Further, the method for analyzing the interference efficiency of the bait array based on the one-dimensional range profile solves an electric field under the condition of time domain pulse incidence to obtain a time domain radar echo, and solves the one-dimensional range profile of the target object, and specifically comprises the following steps:
(1) Through the ray tracing, the far-zone scattered field calculation is carried out, the time step length is set according to the sampling theorem, the electric field calculation is carried out once in one step of time lapse, the scattered field of the target is obtained by approximately integrating the induced current according to the TD-PO method from the Stratton formula in a time domain form, and the PO integral expression of the transient scattered field is as follows under the far-field approximate condition:
Wherein the method comprises the steps ofS is the area of the object illuminated by the plane wave, r is the distance from the point of view to the origin of coordinates O, r' is the position of the point on the curved surface corresponding to ds, < >>Is the external normal unit vector at r' on the plane,/->And->Normalized vectors of the incident wave and the scattered wave, respectively, are here +.> E is normalized polarization direction of incident wave 0 (t) is the time domain electric field strength;
(2) Make the surface integralThe conversion of area division to line integration is performed using the Gordon formula, and the projection of vector κ onto plane S is expressed as:
wherein the method comprises the steps ofThen there are:
I(t)＝E 0 (t)*W(t)；
wherein W (t) is a time function, given by:
here, I μ (t) is the contribution of the μ -th side of S to W (t), written as:
summing the electric fields of all the cells reached by the rays at each moment to obtain the electric field value of the whole time period from the time domain signal reaching the first cell to leaving the last cell, thereby obtaining the radar time domain echo;
(3) By combining the total time-domain scattered signals E s And (r, t) dissolving to obtain:
wherein R (t) is a one-dimensional distance image of the corner reflector, and is expressed as follows:
therefore, the interference effectiveness evaluation analysis of the target ship and the bait array in the complex sea surface environment can be performed.
Further, the method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile utilizes the one-dimensional range profile to perform the interference effectiveness of the bait array under the actual sea state background, and specifically comprises the following steps:
(1) Performing intensity normalization, using 2-norm intensity normalization, adopting a total energy normalization method for each high-resolution range profile sample, and normalizing to obtain a vector for each original high-resolution range profile sample vector x= [ x (1), x (2), ··, x (k) ]:
(2) Interference evaluation is carried out on the one-dimensional range profile results of the bait array at different azimuth angles, so that the similarity of the range profile results of the bait array and the ship targets at all angles is calculated by using a cosine similarity method, and the calculation formula is as follows:
wherein the method comprises the steps ofAnd->HRRP results for a ship target and a bait array at a certain angle of incidence are shown, respectively. The results in the above formula range from (-1, 1), to the intervening phasesThe physical meaning of the similarity is converted into (0, 1);
3) And (3) formulating a specific bait array distribution interference strategy according to various information of ship targets and sea surface backgrounds. Based on a one-dimensional distance image principle, adopting a dilution interference mode to resist radar detection in a search stage, and rapidly arranging a plurality of false targets around the ship by an attacked ship by using a bait array before starting the enemy anti-ship missile terminal guidance device; the probability of finding a target when the radar is not interfered is:
where n is the number of pulses received within the radar half-power wave speed width, S N The average power signal-to-noise ratio of the radar receiving end;
after tactical arrangement with the bait array, the probability of radar target capture is obtained as follows:
P j ＝1-(1-P c ) 1/m ；
wherein m is the total number of targets and interferents in the radar search range;
the diluted interference performance index is measured by the following calculation:
by combining all the technical schemes, the invention has the advantages and positive effects that: based on actual sea condition conditions and physical models, the invention respectively models the bait array, the ship target and the sea surface to obtain a group of integrated models; performing shielding judgment based on the GO method and the ray management theory, and calculating a reflected electric field expression with a time delay term; based on a PO method, carrying out electric field integration to obtain a radar signal time domain echo and a one-dimensional range profile of a target object; based on similarity theory, the interference effectiveness evaluation is carried out on the calculation results of the ship targets and the bait arrays. The invention solves the problem of acquiring one-dimensional range images of ship targets and bait arrays in the complex background in the prior art, and simultaneously effectively solves the problem of analyzing the interference efficiency of the bait arrays in the complex sea and battlefield environment.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following description will briefly explain the drawings needed in the embodiments of the present application, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flow chart of a method for analyzing interference performance of a bait array according to an embodiment of the invention.
Fig. 2 is a schematic diagram of a method for analyzing interference performance of a bait array according to an embodiment of the invention;
FIG. 3 is a modeling flow chart provided by an embodiment of the present invention.
Fig. 4 is a front view of a ship target (alibert grade displacement ship) provided by an embodiment of the present invention.
Fig. 5 is a side view of a ship target (alibert grade displacement ship) provided by an embodiment of the present invention.
Fig. 6 is a diagram of a icosahedral corner reflector provided by an embodiment of the present invention.
FIG. 7 is a sea surface background view provided by the embodiment of the invention, wherein the wind direction angle is 0 degrees, and the wind speed is 3m/s.
FIG. 8 is a sea surface background view provided by the embodiment of the invention, wherein the wind direction angle is 30 degrees, and the wind speed is 5m/s.
Fig. 9 is a flowchart of an incident wave shielding judgment according to an embodiment of the present invention.
FIG. 10 is a flow chart of a path-tracing ray provided by an embodiment of the invention.
Fig. 11 is a flowchart of a scattered electric field calculation according to an embodiment of the present invention.
Fig. 12 is a diluted disturbance profile provided by an embodiment of the present invention.
Fig. 13 is a view of a ship target and sea surface background model provided by an embodiment of the invention.
FIG. 14 is a view of a ship provided by an embodiment of the present inventionThe mark is one-dimensional distance image from the sea surface background (θ=0°, ) A drawing.
Fig. 15 is a diagram of a bait array 1 and a sea surface background model provided by an embodiment of the invention.
Figure 16 shows a one-dimensional distance profile (θ=0°) of a lure array 1 according to an embodiment of the present invention from the background of the sea surface,) A drawing.
Fig. 17 is a diagram of a bait array 2 and a sea surface background model provided by an embodiment of the invention.
Figure 18 is a one-dimensional distance profile (θ=0°) of a lure array 2 provided in accordance with an embodiment of the present invention from the background of the sea surface,) A drawing.
Figure 19 is a model diagram of a ship target and bait array 1 provided by an embodiment of the invention.
Figure 20 is a one-dimensional range profile (θ=0°) of a ship target and bait array 1 provided by an embodiment of the invention,) A drawing.
Fig. 21 is a graph showing the diluted interference distribution of ship targets and bait arrays 1, 2 according to an embodiment of the invention
Fig. 22 shows a one-dimensional range profile (θ=0°) of a diluted interference distribution between a ship target and bait arrays 1 and 2 according to an embodiment of the present invention,) A drawing.
Fig. 23 is a graph showing a comparison of similarity between a ship target and a bait array 1 according to an embodiment of the present invention.
Fig. 24 is a graph showing a comparison of similarity between a ship target and a bait array 2 according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Aiming at the problems in the prior art, the invention provides a bait array interference effectiveness analysis method based on a one-dimensional range profile, and the invention is described in detail below with reference to the accompanying drawings.
As shown in fig. 1, the method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile provided by the invention comprises the following steps:
s101: establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one;
s102: performing shielding judgment on model surface elements in the irradiation range of the radar signals, recording and storing surface element serial numbers after reflection on the propagation path, and recording surface element serial numbers reached by mutual reflection of the models;
s103: solving the electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional range profile of the target object;
s104: interference effectiveness evaluation is performed on the bait array in the actual sea state background by using the one-dimensional distance pair.
One of ordinary skill in the art may implement other steps in the method for performing bait array interference effectiveness analysis based on one-dimensional range profile provided by the present invention, and the method for performing bait array interference effectiveness analysis based on one-dimensional range profile provided by the present invention in fig. 1 is merely one specific embodiment.
As shown in fig. 2, the bait array interference effectiveness analysis system provided by the invention comprises:
the numbering and storing module 1 is used for establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one;
the shielding judgment module 2 is used for carrying out shielding judgment on the model surface elements in the irradiation range of the radar signal, recording and storing the surface element serial numbers reflected on the propagation path, and recording the surface element serial numbers reached by mutual reflection of the models;
the time domain radar echo acquisition module 3 is used for solving an electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional range profile of the target object;
the interference effectiveness evaluation module 4 is used for evaluating the interference effectiveness of the bait array in the actual sea state background by utilizing the one-dimensional distance pair.
The technical scheme of the invention is further described below with reference to the accompanying drawings.
The invention aims to solve the problem that the one-dimensional range profile characteristics of the ship target and the bait array are under the sea warfare background, and based on the actual sea condition and the physical model, the bait array, the ship target and the sea surface are respectively modeled to obtain a group of integrated models; performing shielding judgment based on the GO method and the ray management theory, and calculating a reflected electric field expression with a time delay term; based on a PO method, carrying out electric field integration to obtain a radar signal time domain echo and a one-dimensional range profile of a target object; based on similarity theory, the interference effectiveness evaluation is carried out on the calculation results of the ship targets and the bait arrays.
As shown in fig. 3 and fig. 4, the method for analyzing the interference efficiency of the bait array based on the one-dimensional distance image provided by the embodiment of the invention specifically includes the following steps:
firstly, establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one;
and secondly, carrying out shielding judgment on the model surface elements in the irradiation range of the radar signal, recording and storing the surface element serial numbers reflected on the propagation path, and simultaneously recording the surface element serial numbers reached by mutual reflection of the models.
And thirdly, solving an electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional range profile of the target object.
And fourthly, performing interference effectiveness evaluation on the bait array in the actual sea state background by utilizing the one-dimensional distance.
In a preferred embodiment of the invention, pretreatment is performed to model ship targets, bait arrays, and their sea surfaces. The ship model is formed by selecting an Arabic level expelling ship, a bait array is formed by selecting a icosahedron reflector, and a sea surface environment is formed by selecting a PM sea spectrum. The method specifically comprises the following steps:
1. And (3) building a ship model, and selecting an Aribak-level expelling ship as the ship model, as shown in fig. 5 and 6.
(1) Collecting a model diagram of the ship; a front view and a top view of the lead-in model.
(2) And drawing main characteristic lines by using the RHO software, and drawing the outline shape of the model. And carrying out surface splitting on the basis of the drawn characteristic curve, carrying out surface splitting on the place with trend mutation, establishing a curved surface according to the drawn line, and using a curved surface connection command to achieve curvature continuity of the curved surface.
(3) And (3) establishing a side surface of a ship to carry out mirror image operation, establishing an upper bottom surface and a lower bottom surface, and deleting the ship body according to the requirement to obtain an internal empty groove structure of the ship.
(4) And exporting and storing the established ship model.
2. And (5) establishing an angle reflector model, and carrying out icosahedron angle reflector modeling. The corner reflectors are built step by step based on the geometric model of a regular icosahedron, the triangular emitter being the basic building block thereof.
(1) Firstly, 12 vertexes are found out, every two vertexes are connected to form 30 edges, and the multi-convex polyhedron obtained by the frame is the regular icosahedron.
Establishing an O-XYZ rectangular coordinate system, and respectively establishing three auxiliary rectangles A on the XOY plane, the YOZ plane and the XOZ plane by taking the origin of coordinates as the center i B i C i D i I=1, 2,3, and the three rectangular aspect ratios need to conform to the golden ratio:
these 12 points { A ] i ,B i ,C i ,D i I=1, 2, 3) is twelve vertices of a face of positive 20.
(2) And respectively connecting each point with five points closest to the points to obtain 30 edges, and obtaining the base frame of the icosahedron. On the basis of the constructed regular icosahedron, a triangular structure is added, boolean operation is carried out by utilizing the regular icosahedron, each regular triangle surface is taken as a base, an regular triangular pyramid with equal bottom surfaces and three edges perpendicular to each other is subtracted inwards, and the obtained shape is the geometric model of the regular icosahedron corner reflector, as shown in fig. 7.
3. And establishing a simple rough sea surface model, and taking sea surface wind direction influence into consideration according to a PM sea spectrum formula. PM sea spectrum expression is:
wherein α=8.10×10 -3 Beta=0.74, k is the spatial wave number of the ocean wave, U 19.5 Is the wind speed at 19.5m above the sea surface; g 0 ＝9.81m/s 2 Gravitational acceleration.
Introducing a Longuest-Higgins angle distribution function to simulate the sea surface, wherein the expression is:
wherein,
s in the above formula represents the concentration degree of the direction function, and the spatial wave number and wind speed U 19.5 Related to;indicating the wind direction.
For a two-dimensional sea surface, the direction spectrum can be written as a combination of a general spectrum function and a direction function, namely:
Wherein ()' is an omnidirectional sea spectrum,as a function of the angular distribution.
Through the formula, rough sea surface model programming is performed based on the Monte Carlo method, and sea surface models under different wind directions and wind speeds are constructed. The sea surfaces of different wind directions and wind speeds are shown in fig. 8 and 9.
4. Performing surface element subdivision, and selecting Delaunay triangulation technology. Triangulation is carried out on the established ship target model, the bait array model and the sea surface model thereof, and an index list of each triangle vertex, normal vector and center point of an envelope is obtained, so that a database is established, and the method specifically comprises the following steps:
(1) The three-dimensional Delaunay triangulation based on the Bowyer-Watson algorithm is mainly realized by a point-by-point insertion mode, and the implementation steps are as follows:
1) Constructing a super tetrahedron, including all scattered points, and placing the super tetrahedron into a tetrahedron linked list;
2) Sequentially inserting scattered points in the point set, finding out tetrahedrons with the inserted points in the tetrahedron linked list, deleting common edges affecting the tetrahedrons, connecting the inserted points with all vertexes affecting the tetrahedrons, and completing the insertion of one point in the Delaunay tetrahedron linked list;
3) Optimizing the locally newly formed tetrahedron according to an optimization criterion, and putting the formed tetrahedron into a tetrahedron linked list;
4) Circularly executing the step 2) until all the scattered points are inserted;
(2) After splitting, searching the outer envelope triangle of each region and the corresponding normal vector thereof, wherein the steps are as follows:
1) Judging that in the tetrahedron linked list, if one face is only referenced by one tetrahedron, the face is positioned on the boundary, and returning the serial numbers of the vertexes and the coordinates of each vertex which form the face;
2) The coordinates of the center points of the surfaces are calculated and correspondingly stored, and the calculation formula is as follows:
/>
3) The triangular coordinate points are A (x) 1 ,y 1 ,z 1 )，B(x 2 ,y 2 ,z 2 )，C(x 3 ,y 3 ,z 3 ) The normal vector (a, b, c) of each face and its direction are calculated and stored, and the calculation formula is as follows:
normal vectorObeys the right-handed screw rule, all facing outwards.
In a preferred embodiment of the invention, the shielding judgment is carried out on the model surface elements in the irradiation range of the radar signal, the surface element serial numbers reflected on the propagation path are recorded and stored, and the surface element serial numbers reached by the mutual reflection of the models are recorded. The method specifically comprises the following steps:
(1) The production of the tube intersects the bin using a triangular tube while allowing the triangular tube to coincide with the triangular bin so that the tube does not emit a split upon first order reflection of the target, and a substantial portion of the scattering of the target originates from the first order reflection of the target.
The distinction between dark and bright areas is needed to be made in two cases, namely self-shielding and mutual shielding.
And (3) performing self-shielding judgment: assume thatIs the propagation direction vector of the incident wave, < >>Is the external normal vector of the target patch by judging the vector +.>And->Is used for judging the included angle:
illuminating the area;
a shadow area;
compliance withThe bin of which is the target bin that is occluded.
And (5) performing mutual shielding judgment: mutual occlusion judgment is carried out on the surface element without self occlusion, and three vertexes of the surface element are respectively assumed to beThe initial coordinate of the vector is the origin, then any point on the triangle face is +.>The following equation is satisfied:
wherein u and v represent the weight influence of the vertex on a certain area, and when the weight influence of the vertex on a certain area meets that u is more than or equal to 0, v is more than or equal to 0, and u+v is less than or equal to 1, the point is describedInside the triangular bin.
The ray equation is:wherein (1)>Is the ray direction vector, d is the distance from any point on the ray to the starting point, then the intersection calculation of the ray and the triangle is equivalent to +.>And (5) solving. Substituting the equation to obtain:
and (3) performing equivalent deformation:
by solving the equation above, u, v and the distance d from the ray origin to the intersection point can be obtained.
Order theThen according to the cremmer rule: />
Wherein the method comprises the steps ofAnd solving u and v according to the above formula, and determining whether the ray intersects the triangle surface element by calculating whether the u and v meet the judging condition. The case of no solution is that a ray that is going back from one bin does not intersect with other bins, i.e. no mutual occlusion occurs. Respectively carrying out primary incidence shielding judgment on the bait array, the ship target and the sea surface element, and storing the bait array, the ship target and the sea surface element without being stored The blocked bin number is the area that the ray can illuminate.
(2) A time domain signal is selected. The modulated Gaussian pulses are selected as the excitation time domain signals, and due to their infinite smoothness and stability in a time coordinate system, the frequency domain scattering result of the ultra-wideband can be given, the calculation efficiency is higher than that of the Gordon formula of the frequency domain, and the advantage is more obvious when the frequency domain is sampled more.
Standard modulated gaussian pulse time domain function:
wherein t is 0 Is the offset time, τ is the pulse width, f 0 The center frequency of the Fourier spectrum is a Gao Simai dash. According to the actual incident condition requirement, the bandwidth B and the center frequency f of an incident wave excitation signal are set 0 And τ=4/B.
The reflection of the tube at the illuminated surface element,representing the incident direction unit vector, & lt + & gt>Representing the reflection direction unit vector, ">The outer normal vector of the illuminated bin. The incident wave can be decomposed into TE wave (orthogonal polarization) and TM wave (horizontal polarization) with different rules, and the unit direction vectors are respectively used as +.>And->The reflected wave is similarly represented, and the unit direction vectors are respectively marked as +.>And->
For the followingAnd->The following relationship is satisfied:
After the field intensity of the illuminated surface element is obtained, the reflecting direction of the rays can be obtained by combining the Snell theorem:
selecting the gaussian pulse set as described above as the time domain signal G (t), the time domain incident wave can be expressed as:
wherein the method comprises the steps ofIs the coordinates of the target bin.
The electric field expression after the incident wave is scattered by the surface element for the first time is:
based on the coordinate position of the passing surface element and the ray direction vector, the time delay can be calculated, and the incident field of the incident wave reaching the following surface element after one-time scattering is obtained:
the reflected field intensity and the direction of the reflected rays at the illuminated surface element are obtained, and the reflected field intensity and the reflected direction are used as the secondary incident initial field intensity and the incident direction, so that the ray tracking among the surface elements can be performed for a plurality of times until the rays are emitted out of the target or the ray tracking times reach a set value.
In the preferred embodiment of the invention, the electric field under the incident condition of the time pulse is solved to obtain the time domain radar echo, and the one-dimensional range profile of the target object can be obtained by resolution. The method specifically comprises the following steps:
(1) And performing far-field scattered field calculation through the ray tracing. The length of the time steps is set according to the sampling theorem, and electric field calculation is carried out once in one step according to the time lapse. According to the TD-PO method, starting from the Stratton formula in time domain form, the scattering field of the target is determined by approximate integration of the induced current. The PO integral expression of the transient scatter field is, under far field approximation,:
Wherein the method comprises the steps ofS is the area of the object illuminated by the plane wave, r is the distance from the point of view to the origin of coordinates O, r' is the position of the point on the curved surface corresponding to ds, < >>Is the external normal unit vector at r' on the plane,/->And->Normalized vectors of the incident wave and the scattered wave, respectively, are here +.> E is normalized polarization direction of incident wave 0 And (t) is the time domain electric field strength.
(2) Make the surface integralThe Gordon formula is used here for the conversion of area division into line integrals. The projection of vector κ onto plane S can be expressed as:
wherein the method comprises the steps ofThen there are:
I(t)＝E 0 (t)*W(t)；
wherein W (t) is a time function, given by:
here, I μ (t) the contribution of the μ -th side of S to W (t), can be written as:
summing the electric fields of all the cells reached by the rays at each moment to obtain the electric field value of the whole time period from the time domain signal reaching the first cell to leaving the last cell, thereby obtaining the radar time domain echo;
(3) By combining the total time-domain scattered signals E s And (r, t) dissolving to obtain:
wherein, R (t) is a one-dimensional distance image of the corner reflector, which can be expressed as follows:
therefore, the interference effectiveness evaluation analysis of the target ship and the bait array in the complex sea surface environment can be performed.
In a preferred embodiment of the invention, one-dimensional distance is used to interfere with the efficacy of the bait array in the context of actual sea conditions. The method specifically comprises the following steps:
(1) The radar HRRP echo data is actually vector coherent accumulation of scattering points in each range bin on the radar ray, so that the obtained target information may be insufficient or redundant, and the influence on the accuracy of the bait array interference effectiveness analysis is not insignificant. Proper preprocessing is needed to be carried out on the high-resolution one-dimensional range profile, useless and wrong information in the original data is removed, and the performance of the one-dimensional range profile is improved.
Performing intensity normalization, using 2-norm intensity normalization, using a total energy normalization method for each high-resolution range profile sample, for each original high resolution distance image sample vector x= [ x (1), x (2), x (k), normalizing to obtain a vector:
(2) Interference evaluation is carried out on the one-dimensional range profile results of the bait array at different azimuth angles, so that the similarity of the range profile results of the bait array and the ship targets at all angles is calculated by using a cosine similarity method, and the calculation formula is as follows:
wherein the method comprises the steps ofAnd->HRRP results for a ship target and a bait array at a certain angle of incidence are shown, respectively. The range of the result in the above formula is (-1, 1), and the result is transformed into (0, 1) in the physical meaning of similarity.
3) And (3) formulating a specific bait array distribution interference strategy according to various information of ship targets and sea surface backgrounds. Based on a one-dimensional distance image principle, a dilution interference mode is adopted to resist radar detection in a search stage. The strategy is a remote interference means, which means that before the end guidance device of the enemy anti-warship missile is started, a plurality of decoys are rapidly arranged around the ship by the attacked ship by using a bait array so as to dilute the search of the decoys on the ship and reduce the capture probability of the decoys, thereby achieving the purpose of protecting the ship, and the schematic diagram is shown in figure 13.
The probability of finding a target when the radar is not interfered is:
where n is the number of pulses received within the radar half-power wave speed width, S N Is the average power signal-to-noise ratio of the radar receiving end.
After tactical arrangement with the bait array, the probability of radar target capture is obtained as follows:
P j ＝1-(1-P c ) 1/m ；
wherein m is the total number of targets and interferents in the radar search range.
The diluted interference performance index is measured by the following calculation:
the technical effects of the present invention will be described in detail with reference to simulation.
1. Simulation conditions:
1. the ship target in the simulation adopts an Arabic level expelling ship, the bait array adopts a twenty-face angle reflector, the wind speed of the constructed sea surface model is set to be 5m/s, the wind direction is set to be 0 degree direction angle (namely, the positive direction along the Y axis of the coordinate system), the incident wave adopts Gaussian pulse, the polarization mode is HH polarization, and the specific model and the incident wave conditions are shown in the table 1.
TABLE 1
2. In the simulation, the ship target, namely the Arabic level expelling ship, and the one-dimensional range profile of the bait array 1 and the one-dimensional range profile of the bait array 2 are respectively carried out in all directionsSimilarity comparison.
2. Simulation content and results
Simulation 1, model is built by adopting the experimental parameters No. 1 in table 1, and the results are shown in fig. 14 and 15, and are respectively a composite model of sea background and ship target and an omnibearing model of the modelA one-dimensional range profile.
Simulation 2, model was built using the experimental parameters No. 2 in table 1, and the results are shown in fig. 16 and 17, which are respectively a composite model of the sea background and the bait array 1, and the model was all-roundA one-dimensional range profile.
Simulation 3, model was built using the experimental parameters No. 3 in table 1, and the results are shown in fig. 18 and 19, which are respectively a composite model of the sea background and the bait array 2, and the model was all-roundA one-dimensional range profile.
Simulation 4, model was built using the experimental parameters No. 4 in table 1, and the results are shown in fig. 20 and 21, which are respectively a composite model of a ship target and a bait array 1, a one-dimensional range profile (θ=0°,)。
simulation 5, using the experimental parameters No. 5 in table 1, to build a corresponding dilution type interference model, the results are shown in fig. 22 and 23, which are respectively a composite model of a sea surface target and bait arrays 1 and 2, a one-dimensional distance image (θ=0°, )。
Simulation 6, comparing the similarity of the ship target and the bait array 1 and the bait array 2 to obtain the figure 24.
The invention applies the calculation method through a series of experimental simulations, calculates the one-dimensional range profile of the bait array, the ship target and the sea surface background, and reports the result under the same condition. And the feasibility of interference by utilizing a one-dimensional range profile during radar detection is verified, and the obtained result is consistent with the actual result, so that the method has higher accuracy and practicability and has important value for the research and study of the interference efficiency analysis of the bait array and other non-marginal interference.
In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "head," "tail," and the like are used in an orientation or positional relationship based on that shown in the drawings, merely to facilitate describing the present invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The foregoing is merely illustrative of specific embodiments of the present invention, and the scope of the invention is not limited thereto, but any modifications, equivalents, improvements and alternatives falling within the spirit and principle of the present invention will be apparent to those skilled in the art to which the present invention pertains.
Claims (5)
1. A method for performing bait array interference effectiveness analysis based on one-dimensional range profile, the method comprising:
establishing a bait array, a ship target and a rough sea surface integrated model according to actual sea conditions, splitting the model, and numbering and storing the surface elements one by one;
performing shielding judgment on model surface elements in the irradiation range of the radar signal, recording and storing surface element serial numbers reflected on the propagation path, and recording surface element serial numbers reached by mutual reflection of the models;
solving the electric field under the incident condition of the time domain pulse to obtain a time domain radar echo, and resolving to obtain a one-dimensional range profile of the target object;
performing interference effectiveness evaluation on the bait array under the actual sea state background by utilizing the one-dimensional distance pair;
The method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile comprises the following steps:
establishing a ship target model;
(1) Collecting a model diagram of the ship; front and top views of the lead-in model;
(2) Drawing main characteristic lines by using RHO software, and drawing the outline shape of the model; splitting the surface on the basis of the drawn characteristic curve, splitting the surface at the place with the trend mutation, establishing a curved surface according to the drawn line, and using a curved surface connection command to achieve the curvature continuity of the curved surface;
(3) Establishing a side surface of a ship for mirror image operation, establishing an upper bottom surface and a lower bottom surface, and deleting according to the need to obtain an internal empty groove structure of the ship;
(4) Exporting and storing the established ship model;
establishing an angle reflector model, carrying out icosahedron angle reflector modeling, wherein the angle reflector is established step by step based on a geometric model of a regular icosahedron, and a triangular emitter is a basic constituent unit of the angle reflector;
(1) Firstly, 12 vertexes are found out, 30 edges are formed by two pairs of vertexes, and a multi-convex polyhedron obtained by the frame is a regular icosahedron; establishing an O-XYZ rectangular coordinate system, and respectively establishing three auxiliary rectangles A on the XOY plane, the YOZ plane and the XOZ plane by taking the origin of coordinates as the center i B i C i D i I=1, 2,3, and the three rectangular aspect ratios need to conform to the golden ratio:
these 12 points { A ] i ,B i ,C i ,D i I=1, 2, 3), namely twelve vertices of a positive 20-sided body;
(2) Respectively connecting each point with five points closest to the points to obtain 30 edges to obtain a basic frame of an icosahedron, adding a structure of a triangular surface on the basis of the constructed regular icosahedron, performing Boolean operation by using the regular icosahedron, respectively taking each regular triangle surface as a bottom, and subtracting inwards a regular triangular pyramid with equal bottom surfaces and three edges perpendicular to each other to obtain a geometric model of the regular icosahedron corner reflector;
establishing a simple rough sea surface model, and taking the sea surface wind direction influence into consideration according to a PM sea spectrum formula, wherein the PM sea spectrum expression formula is as follows:
wherein α=8.10×10 -3 Beta=0.74, k is sea waveSpatial wave number, U 19.5 Is the wind speed at 19.5m above the sea surface; g 0 ＝9.81m/s 2 Gravitational acceleration;
introducing a Longuest-Higgins angle distribution function to simulate the sea surface, wherein the expression is:
wherein,
s in the above formula represents the concentration degree of the direction function, and the spatial wave number and wind speed U 19.5 Related to;indicating the wind direction;
for a two-dimensional sea surface, the direction spectrum can be written as a combination of a general spectrum function and a direction function, namely:
Wherein S (K) is an omnidirectional sea spectrum,is an angle distribution function;
through the formula, rough sea surface model programming is performed based on the Monte Carlo method, and sea surface models under different wind directions and wind speeds are constructed.
2. The method for performing bait array interference effectiveness analysis based on one-dimensional distance images according to claim 1, wherein the method for performing bait array interference effectiveness analysis based on one-dimensional distance images performs surface element subdivision, selects Delaunay triangulation technology, triangulates the established ship target model, bait array model and sea surface model thereof, obtains each triangle vertex, normal vector and center point index list of an envelope thereof, and establishes a database, and specifically comprises the following steps:
(1) The three-dimensional Delaunay triangulation based on the Bowyer-Watson algorithm is mainly realized by a point-by-point insertion mode, and the implementation steps are as follows:
1) Constructing a super tetrahedron, including all scattered points, and placing the super tetrahedron into a tetrahedron linked list;
2) Sequentially inserting scattered points in the point set, finding out tetrahedrons with the inserted points in the tetrahedron linked list, deleting common edges affecting the tetrahedrons, connecting the inserted points with all vertexes affecting the tetrahedrons, and completing the insertion of one point in the Delaunay tetrahedron linked list;
3) Optimizing the locally newly formed tetrahedron according to an optimization criterion, and putting the formed tetrahedron into a tetrahedron linked list;
4) Circularly executing the step 2) until all the scattered points are inserted;
(2) After splitting, searching the outer envelope triangle of each region and the corresponding normal vector thereof, wherein the steps are as follows:
1) Judging that in the tetrahedron linked list, if one face is only referenced by one tetrahedron, the face is positioned on the boundary, and returning the serial numbers of the vertexes and the coordinates of each vertex which form the face;
2) The coordinates of the center points of the surfaces are calculated and correspondingly stored, and the calculation formula is as follows:
3) The triangular coordinate points are A (x) 1 ,y 1 ,z 1 )，B(x 2 ,y 2 ,z 2 )，C(x 3 ,y 3 ,z 3 ) The normal vector (a, b, c) of each face and its direction are calculated and stored, and the calculation formula is as follows:
normal vectorObeys the right-handed screw rule, all facing outwards.
3. The method for performing bait array interference effectiveness analysis based on one-dimensional distance images according to claim 1, wherein the method for performing bait array interference effectiveness analysis based on one-dimensional distance images performs shielding judgment on model cells in a radar signal irradiation range, records and stores the sequence numbers of the reflected cells on a propagation path, and records the sequence numbers of the cells reached by mutual reflection of the models, and specifically comprises the following steps:
(1) The production of the ray tube is intersected with the surface element, a triangle ray tube is used, and the triangle ray tube is coincided with the triangle surface element, so that the ray tube does not emit and split when the first-order reflection of the target is carried out, and the main part of the scattering of the target is derived from the first-order reflection of the target;
distinguishing a dark area or a bright area of a surface element, wherein the conditions of self shielding and mutual shielding are needed;
and (3) performing self-shielding judgment: assume thatIs the propagation direction vector of the incident wave, < >>Is the external normal vector of the target patch by judging the vector +.>And->Is used for judging the included angle:
illuminating the area;
a shadow area;
compliance withThe surface element is the blocked target surface element;
and (5) performing mutual shielding judgment: mutual occlusion judgment is carried out on the surface element without self occlusion, and three vertexes of the surface element are respectively assumed to beThe initial coordinate of the vector is the origin, then any point on the triangle face is +.>The following equation is satisfied:
wherein u and v represent the weight influence of the vertex on a certain area, and when the weight influence of the vertex on a certain area meets that u is more than or equal to 0, v is more than or equal to 0, and u+v is less than or equal to 1, the point is describedInside the triangle bin;
the ray equation is:wherein (1)>Is the ray direction vector, d is the distance from any point on the ray to the starting point, then the intersection calculation of the ray and the triangle is equivalent to +. >Solving and substituting into an equation to obtain:
and (3) performing equivalent deformation:
by solving the equation, u, v and the distance d from the ray starting point to the intersection point can be obtained;
order theThen according to the cremmer rule:
wherein the method comprises the steps ofSolving u and v according to the above formula, and determining whether the ray intersects the triangle surface element by calculating whether the u and v meet the judging condition; if no solution exists, the ray which reversely starts from one surface element does not intersect with other surface elements, namely, no mutual shielding exists; the first incident shielding judgment is carried out on the bait array, the ship target and the sea surface element respectively, the non-shielded surface element number is stored, and the non-shielded surface element number is an area which can be illuminated by rays;
(2) Selecting a time domain signal, and selecting a modulation Gaussian pulse as an excitation time domain signal;
standard modulated gaussian pulse time domain function:
wherein t is 0 Is the offset time, τ is the pulse width, f 0 The center frequency of the Fourier spectrum is outlined as a Gaussian pulse, and the bandwidth B and the center frequency f of an incident wave excitation signal are set according to the actual incident condition requirement 0 And τ=4/B;
the reflection of the tube at the illuminated surface element,representing the incident direction unit vector, & lt + & gt>Representing the unit vector of the reflection direction, The external normal vector of the illuminated face element can decompose the incident wave into two components of TE wave and TM wave with different rules, and its unit direction vector is respectively used +.>And->The reflected wave is similarly represented, and the unit direction vectors are respectively marked as +.>And->
For the followingAnd->The following relationship is satisfied:
after the field intensity of the illuminated surface element is obtained, the reflecting direction of the ray is obtained by combining the Snell theorem:
selecting the gaussian pulse set as described above as the time domain signal G (t), the time domain incident wave can be expressed as:
wherein the method comprises the steps ofIs the coordinates of the target bin;
the electric field expression after the incident wave is scattered by the surface element for the first time is:
based on the coordinate position of the passing surface element and the ray direction vector, the time delay can be calculated, and the incident field of the incident wave reaching the following surface element after primary scattering is obtained:
the reflected field intensity and the direction of the reflected rays at the illuminated surface element are obtained, and the reflected field intensity and the reflected direction are used as the secondary incident initial field intensity and the incident direction, so that the ray tracking among the surface elements can be performed for a plurality of times until the rays are emitted out of the target or the ray tracking times reach a set value.
4. The method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile according to claim 1, wherein the method for analyzing the interference effectiveness of the bait array based on the one-dimensional range profile solves an electric field under the condition of time domain pulse incidence to obtain a time domain radar echo, and the method for analyzing the one-dimensional range profile of the target object specifically comprises the following steps:
(1) Through the ray tracing, the far-zone scattered field calculation is carried out, the time step length is set according to the sampling theorem, the electric field calculation is carried out once in one step of time lapse, the scattered field of the target is obtained by approximately integrating the induced current according to the TD-PO method from the Stratton formula in a time domain form, and the PO integral expression of the transient scattered field is as follows under the far-field approximate condition:
wherein the method comprises the steps ofS is the area of the object illuminated by the plane wave, r is the distance from the point of view to the origin of coordinates O, r' is the position of the point on the curved surface corresponding to ds, < >>Is the external normal unit vector at r' on the plane,/->And->Normalized vectors of the incident wave and the scattered wave, respectively, are here +.> E is normalized polarization direction of incident wave 0 (t) is the time domain electric field strength;
(2) Make the surface integralThe conversion of area division to line integration is performed using the Gordon formula, and the projection of vector κ onto plane S is expressed as:
wherein the method comprises the steps ofThen there are:
I(t)＝E 0 (t)*W(t)；
wherein W (t) is a time function, given by:
here, I μ (t) is the contribution of the μ -th side of S to W (t), written as:
summing the electric fields of all the cells reached by the rays at each moment to obtain the electric field value of the whole time period from the time domain signal reaching the first cell to leaving the last cell, thereby obtaining the radar time domain echo;
(3) By combining the total time-domain scattered signals E s And (r, t) dissolving to obtain:
wherein R (t) is a one-dimensional distance image of the corner reflector, and is expressed as follows:
therefore, the interference effectiveness evaluation analysis of the target ship and the bait array in the complex sea surface environment can be performed.
5. The method for analyzing the interference effectiveness of the bait array based on the one-dimensional distance image according to claim 1, wherein the method for analyzing the interference effectiveness of the bait array based on the one-dimensional distance image utilizes the one-dimensional distance image to perform the interference effectiveness of the bait array in the actual sea state background, and specifically comprises the following steps:
(1) Performing intensity normalization, using 2-norm intensity normalization, adopting a total energy normalization method for each high-resolution distance image sample, and normalizing to obtain a vector for each original high-resolution distance image sample vector x= [ x (1), x (2), ··, x (k) ]:
(2) Interference evaluation is carried out on the one-dimensional range profile results of the bait array at different azimuth angles, so that the similarity of the range profile results of the bait array and the ship targets at all angles is calculated by using a cosine similarity method, and the calculation formula is as follows:
wherein the method comprises the steps ofAnd->Respectively representing HRRP results of the ship target and the bait array under a certain angle incidence, wherein the range of the results in the formula is (-1, 1), and the results are converted into (0, 1) in the physical meaning of similarity;
3) According to various information of ship targets and sea surface backgrounds, a specific bait array distribution interference strategy is formulated, based on a one-dimensional range profile principle, a dilution interference mode is adopted to resist radar detection in a search stage, and a plurality of false targets are rapidly arranged around the ship by an attacked ship by utilizing the bait array before a enemy anti-ship missile terminal guidance device is started; the probability of finding a target when the radar is not interfered is:
where n is the number of pulses received within the radar half-power wave speed width, S N The average power signal-to-noise ratio of the radar receiving end;
after tactical arrangement with the bait array, the probability of radar target capture is obtained as follows:
P j ＝1-(1-P c ) 1/m ；
wherein m is the total number of targets and interferents in the radar search range;
the diluted interference performance index is measured by the following calculation:
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012130913A1 (en) * | 2011-03-28 | 2012-10-04 | Peter Huber | Method and apparatus to protect a target against a minimum of one attacking missile |
| CN104914415A (en) * | 2015-05-21 | 2015-09-16 | 中国人民解放军63892部队 | Single-pulse radar coherent jamming method based on target range profile template matching |
| CN109241591A (en) * | 2018-08-21 | 2019-01-18 | 哈尔滨工业大学 | Anti-ship Missile Operational Effectiveness assessment and aid decision-making method |
| CN110907901A (en) * | 2019-10-29 | 2020-03-24 | 西安电子科技大学 | Sea warfare passive interference calculation and evaluation method based on TDSBR |
| CN111830500A (en) * | 2020-04-30 | 2020-10-27 | 南京理工大学 | Radar image simulation method of sea surface ship target based on improved SBR (sequencing batch reactor) rapid imaging technology |
-
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- 2021-01-11 CN CN202110032882.XA patent/CN112859027B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012130913A1 (en) * | 2011-03-28 | 2012-10-04 | Peter Huber | Method and apparatus to protect a target against a minimum of one attacking missile |
| CN104914415A (en) * | 2015-05-21 | 2015-09-16 | 中国人民解放军63892部队 | Single-pulse radar coherent jamming method based on target range profile template matching |
| CN109241591A (en) * | 2018-08-21 | 2019-01-18 | 哈尔滨工业大学 | Anti-ship Missile Operational Effectiveness assessment and aid decision-making method |
| CN110907901A (en) * | 2019-10-29 | 2020-03-24 | 西安电子科技大学 | Sea warfare passive interference calculation and evaluation method based on TDSBR |
| CN111830500A (en) * | 2020-04-30 | 2020-10-27 | 南京理工大学 | Radar image simulation method of sea surface ship target based on improved SBR (sequencing batch reactor) rapid imaging technology |
Non-Patent Citations (1)
| Title |
|---|
| 舰船目标一维距离像的非相干建模计算方法;席泽敏;卢建斌;赵文强;张明敏;苑秉成;;现代雷达(第07期);全文 * |
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