Method and device for simulating electromagnetic scattering characteristics of spatial dynamic cluster target

Abstract

The application provides a space dynamic cluster target electromagnetic scattering characteristic simulation method and device, wherein the method comprises the following steps: based on a preloaded travel trajectory of a cluster target, the travel trajectory is divided into multiple travel stages according to the state of the cluster target; the observation strategy adopted by each travel stage is an overall observation strategy or a separate observation strategy; geometric models of the overall observation strategy and the separate observation strategy are respectively established; the observation time of the cluster target on the travel trajectory is determined based on an observation interval; for each current observation time, the following steps are performed: based on the observation strategy corresponding to the current observation time, the model parameters of the current observation time are updated, so that the electromagnetic scattering echo data of the current observation time is generated according to the updated model parameters; and the electromagnetic scattering echo data corresponding to the travel trajectory is generated based on the electromagnetic scattering echo data of each observation time. According to the scheme, the electromagnetic scattering characteristic simulation accuracy can be improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of electromagnetic scattering characteristic simulation, in particular to a space dynamic cluster target electromagnetic scattering characteristic simulation method and device. BACKGROUND

[0002] Under the background of rapid development of target detection and stealth technology, the space dynamic cluster target has the characteristics of large quantity, strong periodicity and flexible attitude, and the complexity brings great challenge to radar detection. Among the complex characteristics of the dynamic cluster target, the electromagnetic scattering characteristic is a very meaningful characteristic.

[0003] The traditional electromagnetic scattering characteristic calculation is mainly for single or multiple static targets. For the electromagnetic scattering characteristic calculation of moving targets, it can be discretized into a series of electromagnetic scattering characteristic calculations of static targets at a single time. However, in different stages of the cluster target flight, the electromagnetic scattering characteristics of each target and the interaction between targets show different characteristics. The traditional electromagnetic scattering characteristic calculation of single target applied to the space dynamic cluster target has poor accuracy. SUMMARY

[0004] The embodiment of the present application provides a space dynamic cluster target electromagnetic scattering characteristic simulation method and device, which can improve the electromagnetic scattering characteristic simulation accuracy.

[0005] In a first aspect, the embodiment of the present application provides a space dynamic cluster target electromagnetic scattering characteristic simulation method, comprising:

[0006] Based on the preloaded travel trajectory of the cluster target, the travel trajectory is divided into a plurality of travel stages according to the state of the cluster target; wherein the observation strategy adopted in each travel stage is an overall observation strategy or a separate observation strategy;

[0007] The geometric model of the overall observation strategy and the separate observation strategy is established respectively;

[0008] The observation time of the cluster target on the travel trajectory is determined based on the observation interval;

[0009] For each current observation time, the following is performed: based on the observation strategy corresponding to the current observation time, the model parameters of the current observation time are updated to generate the electromagnetic scattering echo data of the current observation time according to the updated model parameters;

[0010] Based on the electromagnetic scattering echo data of each observation time, the electromagnetic scattering echo data corresponding to the travel trajectory is generated.

[0011] In one possible implementation, the trajectory of the cluster target based on the pre-loaded cluster target is divided into a plurality of travel stages according to the state of the cluster target, including:

[0012] Based on the pre-loaded trajectory of the cluster target, it is determined whether the distance between the cluster targets at each time meets the first set condition;

[0013] If yes, the electromagnetic scattering characteristics of the overall observation strategy and the individual observation strategy are determined, and the influence degree of the total coupling scattering characteristics on the radar observation result is determined according to the electromagnetic scattering characteristics difference and the electromagnetic scattering characteristics of the individual observation strategy; when the influence degree is less than a threshold value, the individual observation strategy is adopted at this time; when the influence degree is not less than the threshold value, the overall observation strategy is adopted at this time;

[0014] If no, the overall observation strategy is adopted at this time;

[0015] Based on the observation strategy adopted at each time, a plurality of travel stages of the cluster target on the trajectory are formed.

[0016] In one possible implementation, the geometric model of the overall observation strategy and the individual observation strategy is established respectively, including:

[0017] Based on the radar latitude and longitude coordinates, the radar coordinates in the geocentric and terrestrial coordinate system are determined;

[0018] According to the radar coordinates in the geocentric and terrestrial coordinate system, the radar line-of-sight direction vector in the geocentric and terrestrial coordinate system corresponding to each observation strategy is determined;

[0019] The radar line-of-sight direction vector in the geocentric and terrestrial coordinate system is converted to the target body coordinate system to obtain the azimuth angle and the pitch angle of the radar line-of-sight direction vector in the target body coordinate system according to the radar line-of-sight direction vector in the target body coordinate system;

[0020] Based on the conversion relationship between the north celestial east coordinate system and the geocentric and terrestrial coordinate system and the target attitude angle in the north celestial east coordinate system, the target attitude angle in the radar coordinate system is determined.

[0021] In one possible implementation, for the overall observation strategy, the radar line-of-sight direction vector in the geocentric and terrestrial coordinate system is determined by the difference between the radar coordinates in the geocentric and terrestrial coordinate system and the origin coordinates of the cluster target reference coordinate system;

[0022] For the individual observation strategy, the radar line-of-sight direction vector in the geocentric and terrestrial coordinate system is determined by the difference between the radar coordinates in the geocentric and terrestrial coordinate system and the target coordinates.

[0023] In a possible implementation manner, the generating of the electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation moment comprises:

[0024] The period t1 of the attitude angle change of the target is extracted by using the AMDF method.

[0025] The first RCS sequence is obtained by calculating the time corresponding to the t1 length before each observation moment, the median value of the first RCS sequence is calculated, the maximum value in each t1 length is curve fitted, the data between adjacent observation moments is filled based on the fitted curve to obtain the second RCS sequence, and the filled data is adjusted according to the fitted curve based on the median value to obtain the adjusted electromagnetic scattering echo data.

[0026] In a possible implementation manner, the extracting of the period t1 of the attitude angle change of the target by using the AMDF method comprises:

[0027] The first attitude angle sequence is obtained by performing AMDF calculation on the acquired target attitude angle sequence.

[0028] The second attitude angle sequence is obtained by performing CHF-AMDF processing on the first attitude angle sequence.

[0029] The difference sequence is obtained by performing difference operation on the first attitude angle sequence and the second attitude angle sequence.

[0030] The third attitude angle sequence is obtained by performing CAMDF processing on the difference sequence.

[0031] The peak point of the third attitude angle sequence is determined, and the valley point is searched from the edge direction of the third attitude angle sequence starting from the peak point; the length of the valley point and the peak point is not greater than half of the length of the third attitude angle sequence.

[0032] The quotient value obtained by dividing the position of the valley point by the sampling frequency is determined as the period t1 of the attitude angle change of the target.

[0033] In a possible implementation manner, the adjusting of the filled data according to the fitted curve based on the median value comprises:

[0034] The adjusted electromagnetic scattering echo data E3(i) is obtained by adjusting according to the following formula:

[0035]

[0036] Wherein, P(j) is a sequence composed of the maximum values of the data in each t1 length, Med is the median value, Fit(i) is the fitted curve value corresponding to each time i, and E2(i) is the second RCS sequence.

[0037] In a second aspect, the embodiments of the present application further provide a device for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target, comprising:

[0038] a division unit configured to divide a travel trajectory of the cluster target into a plurality of travel stages according to a state of the cluster target based on the travel trajectory loaded in advance, wherein an observation strategy adopted by each travel stage is an overall observation strategy or an individual observation strategy;

[0039] a model establishment unit configured to establish geometric models of the overall observation strategy and the individual observation strategy respectively;

[0040] a determination unit configured to determine observation time points of the cluster target on the travel trajectory based on observation intervals;

[0041] an echo data generation unit configured to, for each current observation time point, perform the following: updating model parameters of the current observation time point based on an observation strategy corresponding to the current observation time point, so as to generate electromagnetic scattering echo data of the current observation time point according to the updated model parameters;

[0042] The echo data generation unit is further configured to generate electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation time point.

[0043] In a third aspect, the embodiments of the present application further provide an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in any of the embodiments of the present application.

[0044] In a fourth aspect, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program, and the computer program, when executed in a computer, causes the computer to execute the method described in any of the embodiments of the present application.

[0045] The embodiments of the present application provide a method and a device for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target, the travel trajectory is divided into a plurality of travel stages according to a state of the cluster target, so that different observation strategies are adopted in different travel stages, the state of the target is considered in the division, and whether the coupling scattering problem is generated or not, and by establishing geometric models of different observation strategies, the geometric models can be updated in real time when the electromagnetic scattering echo data is generated, so that the simulation accuracy of the electromagnetic scattering characteristics of the spatial dynamic cluster target can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0047] Figure 1 is a flow chart of a space dynamic cluster target electromagnetic scattering characteristic simulation method provided by an embodiment of the present application;

[0048] Figure 2 is a hardware architecture diagram of an electronic device provided by an embodiment of the present application;

[0049] Figure 3 is a structure diagram of a space dynamic cluster target electromagnetic scattering characteristic simulation device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort fall within the protection scope of the present application.

[0051] Please refer to Figure 1 The embodiment of the present application provides a space dynamic cluster target electromagnetic scattering characteristic simulation method, which comprises the following steps.

[0052] Step 100, based on the preloaded travel trajectory of the cluster target, the travel trajectory is divided into multiple travel stages according to the state of the cluster target; Wherein, the observation strategy adopted by each travel stage is the overall observation strategy or the individual observation strategy;

[0053] Step 102, the geometric model of the overall observation strategy and the individual observation strategy is established respectively;

[0054] Step 104, based on the observation interval, the observation time of the cluster target on the travel trajectory is determined;

[0055] Step 106, for each current observation time, the following is executed: based on the observation strategy corresponding to the current observation time, the model parameters of the current observation time are updated, so as to generate the electromagnetic scattering echo data of the current observation time according to the updated model parameters;

[0056] Step 108, based on the electromagnetic scattering echo data of each observation time, the electromagnetic scattering echo data corresponding to the travel trajectory is generated.

[0057] In the embodiment of the application, the travel trajectory is divided into multiple travel stages according to the state of the cluster target, so that different observation strategies are adopted in different travel stages, and whether the state of the target produces coupling scattering problems is fully considered, and by establishing a geometric model of different observation strategies, the electromagnetic scattering characteristic simulation accuracy of the spatial dynamic cluster target can be improved by real-time updating of the geometric model when generating the electromagnetic scattering echo data.

[0058] The following describes Figure 1 The execution mode of each step is shown.

[0059] Firstly, for step 100, based on the preloaded travel trajectory of the cluster target, the travel trajectory is divided into multiple travel stages according to the state of the cluster target; wherein the observation strategy adopted in each travel stage is the overall observation strategy or the separate observation strategy.

[0060] Before the cluster target navigates or flies, the travel trajectory is pre-planned, so the travel trajectory of the cluster target can be preloaded for subsequent processing.

[0061] In radar detection, when the distance between targets is small, the coupling scattering characteristics will be more significant. In electromagnetic scattering calculation, for the cluster target scene, when the coupling effect between targets is weakened to a certain extent, it can be ignored in the calculation, thereby reducing the calculation amount and improving the calculation efficiency.

[0062] In the embodiment of the application, the step 100 can be implemented by at least the following steps A1-A4:

[0063] A1, based on the preloaded travel trajectory of the cluster target, it is determined whether the distance between the cluster targets at each time satisfies the first set condition; if yes, step A2 is executed; if no, step A3 is executed;

[0064] In order to evaluate the coupling scattering effect when the distance between targets is large, when the distance between targets satisfies the first set condition, the coupling scattering characteristic evaluation is performed in the calculation, wherein the first set condition can be:

[0065]

[0066] Wherein, R ij represents the distance between the ith target and the jth target in the cluster, L i and L j respectively represent the maximum size of the ith target and the jth target, and λ is the wavelength of the electromagnetic wave.

[0067] A2, determining electromagnetic scattering characteristic difference of the overall observation strategy and the individual observation strategy; and determining the influence degree of the total coupling scattering characteristic on the radar observation result according to the electromagnetic scattering characteristic difference and the electromagnetic scattering characteristic of the individual observation strategy; when the influence degree is less than a threshold value, the individual observation strategy is adopted at the moment; when the influence degree is not less than the threshold value, the overall observation strategy is adopted at the moment;

[0068] In the calculation, in order to evaluate the coupling scattering characteristic, under the condition of meeting the first set condition, the difference evaluation of the cluster target overall calculation and the individual target calculation is carried out by taking a large time interval, and the electromagnetic scattering characteristic difference obtained by the two ways can be expressed as:

[0069]

[0070] Wherein, E s (f k ) represents the electromagnetic scattering characteristic of the kth frequency point f k in the cluster target overall calculation, E s,n (f k ) represents the electromagnetic scattering characteristic of the nth target at the kth frequency point f k in the individual target calculation, and ΔE s (f k ) represents the electromagnetic scattering characteristic difference obtained by the two ways at the frequency point.

[0071] Therefore, the influence degree η of the total coupling scattering characteristic on the radar observation result can be obtained, which is represented by the ratio of the coupling scattering echo power and the individual target independent scattering echo power, that is:

[0072]

[0073] When η is less than a specified threshold value η0, that is, η < η0, the coupling scattering characteristic can be ignored, and the individual observation strategy is adopted. When η is large, the coupling scattering cannot be ignored, and the overall observation strategy is adopted.

[0074] A3, the overall observation strategy is adopted at the moment;

[0075] A4, based on the observation strategy adopted at each moment, a plurality of travel stages of the cluster target on the travel trajectory are formed.

[0076] In the division, if the observation strategies adopted at adjacent moments are the same, they are divided into the same travel stage.

[0077] It should be noted that in addition to the above manner of dividing the travel trajectory into multiple travel stages, other manners can also be used, such as setting a distance threshold, if the distance of the cluster target exceeds the distance threshold, a separate observation strategy is adopted, otherwise a whole observation strategy is adopted, and the travel stage is divided based on the determined observation strategy.

[0078] Then, for step 102, geometric models of the whole observation strategy and the separate observation strategy are respectively established.

[0079] The method for modeling the cluster target observation scene geometry converts the scene of observing dynamic cluster targets by the radar into parameter information varying with the radar line-of-sight direction, including the real-time azimuth angle and the real-time elevation angle of the radar relative to the target and the real-time attitude angle of the target under the radar observation, by establishing the geocentric geodetic coordinate system, the radar coordinate system, the north celestial east coordinate system, and the cluster target reference coordinate system.

[0080] Specifically, the process of establishing the geometric model in this step 102 can include the following steps B1-B4:

[0081] B1, based on the radar longitude and latitude coordinates, determine the radar coordinates in the geocentric geodetic coordinate system;

[0082] The conversion relationship between the longitude and latitude coordinates and the radar coordinates in the geocentric geodetic coordinate system is:

[0083]

[0084] Where (X, Y, Z) is the radar coordinate in the geocentric geodetic coordinate system, e is the eccentricity of the ellipsoid, and N is the curvature radius of the reference ellipsoid.

[0085] The radar coordinates in the geocentric geodetic coordinate system can be obtained from the conversion relationship between the longitude and latitude coordinates and the coordinates in the geocentric geodetic coordinate system.

[0086] B2, according to the radar coordinates in the geocentric geodetic coordinate system, determine the radar line-of-sight direction vector in the geocentric geodetic coordinate system corresponding to each observation strategy;

[0087] In the embodiment of the application, for the whole observation strategy, the radar line-of-sight direction vector in the geocentric geodetic coordinate system is determined by the difference between the radar coordinates in the geocentric geodetic coordinate system and the origin coordinates of the cluster target reference coordinate system, specifically, the cluster target reference coordinate system is established, and the radar line-of-sight direction vector in the geocentric geodetic coordinate system is:

[0088] k1=(X Radar -X ref ,Y Radar -Y ref ,Z Radar -Zref

[0089] wherein, X ref , Y ref , Z ref is the origin coordinate of the cluster target reference coordinate system, X Radar , Y Radar , Z Radar is the radar coordinate in the earth-centered earth-fixed coordinate system.

[0090] In the embodiment of the application, for the single observation strategy, the radar line-of-sight direction vector in the earth-centered earth-fixed coordinate system is determined by the difference between the radar coordinate and the target coordinate in the earth-centered earth-fixed coordinate system, and specifically, the radar line-of-sight direction vector in the earth-centered earth-fixed coordinate system is:

[0091] k1=(X Radar -X, Y Radar -Y, Z Radar -Z)

[0092] wherein, X, Y, Z are the current time trajectory point coordinates of the target, X Radar , Y Radar , Z Radar is the radar coordinate in the earth-centered earth-fixed coordinate system.

[0093] B3, converting the radar line-of-sight direction vector in the earth-centered earth-fixed coordinate system to the target body coordinate system to obtain the azimuth angle and the elevation angle of the radar line-of-sight direction vector in the target body coordinate system according to the radar line-of-sight direction vector in the target body coordinate system;

[0094] The radar line-of-sight direction vector in the earth-centered coordinate system is converted to the target body coordinate system through coordinate conversion. Let the radar line-of-sight direction vector converted to the target body coordinate system be k2, which is expressed as Then the azimuth angle and the elevation angle of the radar line-of-sight direction vector in the target body coordinate system can be obtained:

[0095]

[0096]

[0097] wherein, is the azimuth angle of the radar line-of-sight direction vector in the target body coordinate system, and θ is the elevation angle of the radar line-of-sight direction vector in the target body coordinate system.

[0098] B4, determining the target attitude angle in the radar coordinate system based on the conversion relationship between the north-east coordinate system and the earth-centered earth-fixed coordinate system and the target attitude angle in the north-east coordinate system.

[0099] ​The target attitude angle based on prior knowledge is defined in the north-east coordinate system, and thus needs to be obtained in the radar coordinate system by the conversion relationship between the north-east coordinate system and the earth-fixed coordinate system. The attitude conversion matrix from the north-east coordinate system to the earth-fixed coordinate system is:

[0100]

[0101] wherein L is longitude, B is latitude, and H is height.

[0102] Similarly, since the attitude conversion matrix is an orthogonal matrix, according to the property of the orthogonal matrix: the inverse matrix of the orthogonal matrix is equal to the transpose matrix thereof, the attitude conversion matrix from the earth-fixed coordinate system to the north-east coordinate system is:

[0103]

[0104] The attitude conversion matrix from the north-east coordinate system to the radar coordinate system can be used to inversely deduce the target attitude angle in the radar coordinate system. Assuming that the attitude conversion matrix is:

[0105]

[0106] The attitude angle can be inversely deduced from the attitude conversion matrix as:

[0107] α=arctan(C 32 ,C 33 )

[0108] β=asin(-C 31 )

[0109] γ=arctan(C 21 ,C 11 )

[0110] wherein γ is a yaw angle, β is a pitch angle, and α is a roll angle.

[0111] Next, the step 104 "determining observation time of the cluster target on the travel trajectory based on an observation interval" and the step 106 "performing, for each current observation time, the following: updating model parameters of the current observation time based on an observation strategy corresponding to the current observation time, to generate electromagnetic scattering echo data of the current observation time according to the updated model parameters" are simultaneously explained.

[0112] The observation interval can be set according to actual requirements, or can be real-time observation.

[0113] For the overall observation strategy, the geometric model, target attitude angle, target position relative to the cluster coordinate system and radar line-of-sight information at each time are updated. For the individual observation strategy, the target attitude angle and radar line-of-sight information at each time are updated to obtain the electromagnetic scattering echo data at the current observation time.

[0114] In the target scattering feature analysis and extraction, through the analysis of HRRP, it is known that the scattering echoes generated by different scattering mechanisms can be separated if they do not coincide in space and exhibit obvious scattering center features. The complex exponential (CE) model can be used to describe and extract the parameter information of each scattering center contained in the target scattering feature, especially the position of the scattering center relative to the reference center, so as to be used for target scattering feature extraction. Before solving the model parameters, the number of target scattering centers needs to be estimated. Assuming that the scattering of the target is obtained by superimposing the phasors of P scattering centers, the frequency domain scattering field calculated by the PO+SBR method is E s (f k ), and the target scattering field represented by the complex exponential model is:

[0115]

[0116] where a i and α i represent the complex amplitude and frequency dispersion factor of the i-th scattering center, respectively; r i is the distance from the i-th scattering center to the reference center of the target, and c is the speed of light. If the initial frequency is f1, the frequency vector is:

[0117] f k = f1+(k-1)Δf(k=1,2,…,N)

[0118] In the model parameter solving process, the dimension of the Hankel matrix established is determined according to the estimated model order, which is the maximum estimation of the number of scattering centers. According to the input sparse frequency point scattering field echo data, the model parameters a i , α i and r i are solved through matrix operation, and the scattering field echo data corresponding to the dense frequency points are obtained.

[0119] Finally, for step 108, the electromagnetic scattering echo data corresponding to the travel trajectory is generated based on the electromagnetic scattering echo data at each observation time.

[0120] Since the cluster target is observed at observation intervals, part of the echo data will be missed, so it is necessary to generate the electromagnetic scattering echo data of the entire travel trajectory. Specifically, step 108 can be implemented by the following steps:

[0121] C1, extracting the attitude angle change period t1 of the target by using the AMDF method;

[0122] For a periodically moving target, the RCS sequence at a single frequency point of the target presents periodic changes with the attitude angle. For a target with periodic changes in the attitude angle, the AMDF method can be used to extract the period of the target. Specifically, this step can include:

[0123] C11, performing AMDF calculation on the acquired target attitude angle sequence to obtain a first attitude angle sequence;

[0124] C12, performing CHF-AMDF processing on the first attitude angle sequence to obtain a second attitude angle sequence;

[0125] C13, performing difference operation on the first attitude angle sequence and the second attitude angle sequence to obtain a corresponding difference sequence;

[0126] C14, performing CAMDF processing on the difference sequence to obtain a third attitude angle sequence;

[0127] C15, determining a peak point of the third attitude angle sequence, and searching for a valley point from the edge direction of the third attitude angle sequence starting from the peak point; the length of the valley point and the peak point is not greater than half the length of the third attitude angle sequence;

[0128] C16, determining the quotient value of the valley point position divided by the sampling frequency as the attitude angle change period of the target.

[0129] C2, calculating the time corresponding to the time length t1 before each observation time to obtain a first RCS sequence; calculating the median value of the first RCS sequence; performing curve fitting on the maximum value in each t1 time length; filling the data between adjacent observation times based on the fitted curve to obtain a second RCS sequence, and adjusting the filled data according to the fitted curve based on the median value to obtain adjusted electromagnetic scattering echo data.

[0130] Wherein, the observation interval can be t2. When performing curve fitting, the cubic in the cftool toolbox in Matlab can be used to perform curve fitting on the maximum value points. When filling the data between adjacent observation times, the data of each t1 time length is copied to fill.

[0131] In this step, during adjustment, the impact of data less than the median value is very low, so no adjustment processing is performed on this part of data. For data greater than the median value, adjustment is performed according to the ratio, which can be adjusted according to the following formula to obtain adjusted electromagnetic scattering echo data E3(i):

[0132]

[0133] wherein P(j) is a sequence of maximum values of data in each t1 time length, Med is the median value, Fit(i) is a fitting curve value corresponding to each time i, and E2(i) is the second RCS sequence.

[0134] As shown in Figure 2 , Figure 3 , an embodiment of the present application provides a device for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware layer, as shown in Figure 2 , a hardware architecture diagram of an electronic device in which the device for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target is located, in addition to the processor, the memory, the network interface, and the non-volatile memory shown in Figure 2 , the electronic device in which the device is located in the embodiment can usually include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking the software implementation as an example, as shown in Figure 3 , as a device in a logical sense, it is formed by the CPU of the electronic device in which it is located reading the corresponding computer program in the non-volatile memory into the memory for running. The device for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target provided in the embodiment includes:

[0135] The dividing unit 301 is configured to divide the travel trajectory of the cluster target into a plurality of travel stages according to the state of the cluster target based on the preloaded travel trajectory of the cluster target; wherein the observation strategy adopted by each travel stage is an overall observation strategy or a separate observation strategy.

[0136] The model establishing unit 302 is configured to establish geometric models of the overall observation strategy and the separate observation strategy, respectively.

[0137] The determining unit 303 is configured to determine observation time points of the cluster target on the travel trajectory based on an observation interval.

[0138] The echo data generating unit 304 is configured to, for each current observation time point, perform: updating model parameters of the current observation time point based on an observation strategy corresponding to the current observation time point, to generate electromagnetic scattering echo data of the current observation time point according to the updated model parameters.

[0139] The echo data generating unit 304 is further configured to generate electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation time point.

[0140] In an embodiment of the present application, the dividing unit is specifically configured to: determine whether the distance between the cluster targets at each time meets a first set condition based on the preloaded travel trajectory of the cluster target; if yes, determine the electromagnetic scattering characteristic difference between the overall observation strategy and the individual observation strategy; and determine the influence degree of the total coupling scattering characteristic on the radar observation result according to the electromagnetic scattering characteristic difference and the electromagnetic scattering characteristic of the individual observation strategy; when the influence degree is less than a threshold value, the individual observation strategy is adopted at the time; when the influence degree is not less than the threshold value, the overall observation strategy is adopted at the time; if not, the overall observation strategy is adopted at the time; and form a plurality of travel stages of the cluster target on the travel trajectory based on the observation strategy adopted at each time.

[0141] In an embodiment of the present application, the model establishing unit is specifically configured to: determine the radar coordinates in the geocentric geodetic coordinate system based on the radar latitude-longitude-height coordinates; determine the radar line-of-sight direction vector in the geocentric geodetic coordinate system corresponding to each observation strategy according to the radar coordinates in the geocentric geodetic coordinate system; convert the radar line-of-sight direction vector in the geocentric geodetic coordinate system to the target body system to obtain the azimuth angle and the elevation angle of the radar line-of-sight direction vector in the target body system according to the radar line-of-sight direction vector in the target body system; and determine the target attitude angle in the radar coordinate system based on the conversion relationship between the north celestial east coordinate system and the geocentric geodetic coordinate system and the target attitude angle in the north celestial east coordinate system.

[0142] In an embodiment of the present application, for the overall observation strategy, the radar line-of-sight direction vector in the geocentric geodetic coordinate system is determined by the difference between the radar coordinates in the geocentric geodetic coordinate system and the origin coordinates of the cluster target reference coordinate system; and for the individual observation strategy, the radar line-of-sight direction vector in the geocentric geodetic coordinate system is determined by the difference between the radar coordinates in the geocentric geodetic coordinate system and the target coordinates.

[0143] In an embodiment of the present application, when the echo data generating unit generates the electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data at each observation time, it is specifically configured to extract the attitude angle change period t1 of the target by using the AMDF method; calculate the first RCS sequence by calculating the time corresponding to each t1 length before each observation time; calculate the median value of the first RCS sequence; perform curve fitting on the maximum value in each t1 length; fill the data between adjacent observation times based on the fitting curve to obtain the second RCS sequence, and adjust the filled data according to the fitting curve based on the median value to obtain the adjusted electromagnetic scattering echo data.

[0144] In one embodiment of the present application, when the echo data generating unit extracts the attitude angle change period of the target by using the AMDF method, it is specifically used for: performing AMDF calculation on the acquired target attitude angle sequence to obtain a first attitude angle sequence; performing CHF-AMDF processing on the first attitude angle sequence to obtain a second attitude angle sequence; performing difference operation on the first attitude angle sequence and the second attitude angle sequence to obtain a corresponding difference sequence; performing CAMDF processing on the difference sequence to obtain a third attitude angle sequence; determining the peak point of the third attitude angle sequence, and searching for a valley point from the edge direction of the third attitude angle sequence starting from the peak point; the length of the valley point and the peak point is not greater than half of the length of the third attitude angle sequence; and determining the quotient value of the valley point position divided by the sampling frequency as the attitude angle change period of the target.

[0145] In one embodiment of the present application, when the echo data generating unit adjusts the filled data according to the median value according to the fitting curve, it is specifically used for adjusting according to the following formula to obtain adjusted electromagnetic scattering echo data E3(i):

[0146]

[0147] Wherein, P(j) is a sequence composed of maximum values of data in each t1 time length, Med is the median value, Fit(i) is the fitting curve value corresponding to each time i, and E2(i) is the second RCS sequence.

[0148] It can be understood that the structure shown in the embodiment of the present application does not constitute a specific limitation on the space dynamic cluster target electromagnetic scattering characteristic simulation device. In other embodiments of the present application, a space dynamic cluster target electromagnetic scattering characteristic simulation device can include more or fewer components than the diagram, or combine certain components, or split certain components, or different component arrangement. The components shown can be realized in hardware, software or a combination of software and hardware.

[0149] The information interaction, execution process and the like between the modules in the above device are based on the same concept as the method embodiments of the present application, and the specific content can be referred to the description in the method embodiments of the present application, which will not be described here.

[0150] The embodiment of the present application also provides an electronic device, which comprises a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, a space dynamic cluster target electromagnetic scattering characteristic simulation method in any one of the embodiments of the present application is realized.

[0151] The embodiment of the present application also provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program enables a processor to execute the spatial dynamic cluster target electromagnetic scattering characteristic simulation method in any of the embodiments of the present application when the computer program is executed by the processor.

[0152] Specifically, a system or device provided with a storage medium storing software program codes implementing the functions of any of the above embodiments, and enabling a computer (or CPU or MPU) of the system or device to read and execute the program codes stored in the storage medium.

[0153] In this case, the program codes read from the storage medium can implement the functions of any of the above embodiments by themselves, and thus the program codes and the storage medium storing the program codes constitute a part of the present application.

[0154] The storage medium for providing the program codes includes floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, nonvolatile memory cards and ROMs. Alternatively, the program codes can be downloaded from a server computer through a communication network.

[0155] In addition, it should be clear that not only the program codes read by the computer can be executed, but also part or all of the actual operations can be completed by operating systems and the like operating on the computer based on the instructions of the program codes, so as to implement the functions of any of the above embodiments.

[0156] In addition, it should be understood that the program codes read from the storage medium can be written into the memory provided in the expansion board inserted into the computer or the memory provided in the expansion module connected to the computer, and then part or all of the actual operations can be executed by the CPU and the like installed on the expansion board or the expansion module based on the instructions of the program codes, so as to implement the functions of any of the above embodiments.

[0157] It should be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0158] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware, and the foregoing program can be stored in a computer readable storage medium, and the program performs the steps of the above-mentioned method embodiments when executed; and the foregoing storage medium includes various storage media that can store program codes, such as ROM, RAM, magnetic disk or optical disk.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for simulating electromagnetic scattering characteristics of a spatial dynamic cluster target, characterized in that, The method comprises the following steps: dividing a preloaded travel trajectory of a cluster target into multiple travel stages according to the state of the cluster target, wherein an observation strategy adopted by each travel stage is an overall observation strategy or an individual observation strategy; establishing a geometric model of the overall observation strategy and the individual observation strategy respectively; determining observation time points of the cluster target on the travel trajectory based on an observation interval; for each current observation time point, performing the following steps: updating model parameters of the current observation time point based on an observation strategy corresponding to the current observation time point, so as to generate electromagnetic scattering echo data of the current observation time point according to the updated model parameters; generating electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation time point; The generating of the electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation time comprises: extracting the attitude angle change period of the target by using an AMDF method ; calculating the time corresponding to each observation time before the time length to obtain a first RCS sequence; calculating the median value of the first RCS sequence; performing curve fitting on the maximum value in each time length; filling the data between adjacent observation times based on the fitted curve to obtain a second RCS sequence, and adjusting the filled data according to the fitted curve based on the median value to obtain adjusted electromagnetic scattering echo data; The adjusting the filled data according to the median value in a fitting curve manner comprises adjusting according to the following formula to obtain adjusted electromagnetic scattering echo data : wherein, is the maximum value of the data in each time interval, is the sequence of the maximum values of the data in each time interval, is the median value, is the value of the fitting curve corresponding to each time instant i, is the second RCS sequence.

2. The method of claim 1, wherein, the step of dividing the preloaded travel trajectory of the cluster target into multiple travel stages according to the state of the cluster target comprises the following steps: determining whether the distance between the cluster targets at each time point meets a first set condition based on the preloaded travel trajectory of the cluster target; if yes, determining the electromagnetic scattering characteristic difference between the overall observation strategy and the individual observation strategy, and determining the influence degree of the total coupling scattering characteristic on the radar observation result according to the electromagnetic scattering characteristic difference and the electromagnetic scattering characteristic of the individual observation strategy; when the influence degree is less than a threshold value, the individual observation strategy is adopted at the time point; when the influence degree is not less than the threshold value, the overall observation strategy is adopted at the time point; if no, the overall observation strategy is adopted at the time point; forming multiple travel stages of the cluster target on the travel trajectory based on the observation strategy adopted at each time point.

3. The method of claim 1, wherein, the step of establishing the geometric model of the overall observation strategy and the individual observation strategy respectively comprises the following steps: determining radar coordinates in a geocentric geodetic coordinate system based on radar latitude-longitude-height coordinates; determining radar line-of-sight direction vectors in the geocentric geodetic coordinate system corresponding to each observation strategy; converting the radar line-of-sight direction vectors in the geocentric geodetic coordinate system to a target body coordinate system to obtain the azimuth angle and the elevation angle of the radar line-of-sight direction vectors in the target body coordinate system according to the radar line-of-sight direction vectors in the target body coordinate system; determining target attitude angles in the radar coordinate system based on the conversion relationship between the north celestial east coordinate system and the geocentric geodetic coordinate system and the target attitude angles in the north celestial east coordinate system.

4. The method according to claim 3, wherein for the overall observation strategy, the radar line-of-sight direction vector in the geocentric geodetic coordinate system is determined by the difference between the radar coordinates in the geocentric geodetic coordinate system and the origin coordinates of the cluster target reference coordinate system; for the individual observation strategy, the radar line-of-sight direction vector in the geocentric geodetic coordinate system is determined by the difference between the radar coordinates in the geocentric geodetic coordinate system and the target coordinates.

5. The method of claim 1, wherein, The method comprises the following steps: performing AMDF calculation on the obtained target attitude angle sequence to obtain a first attitude angle sequence; performing CHF-AMDF processing on the first attitude angle sequence to obtain a second attitude angle sequence; performing difference operation on the first attitude angle sequence and the second attitude angle sequence to obtain a corresponding difference sequence; The difference value sequence is processed by CAMDF to obtain a third attitude angle sequence; A peak point of the third attitude angle sequence is determined, and a valley point is searched from an edge direction of the third attitude angle sequence starting from the peak point; a length of the valley point and the peak point is not greater than half of a length of the third attitude angle sequence; A quotient value obtained by dividing the valley point position by a sampling frequency is determined as a target attitude angle change period.

6. A device for simulating electromagnetic scattering characteristics of a space dynamic cluster target, characterized in that, Comprise: The dividing unit is configured to divide a travel trajectory of the cluster target into a plurality of travel stages according to a state of the cluster target based on a preloaded travel trajectory of the cluster target; wherein an observation strategy adopted by each travel stage is an overall observation strategy or a separate observation strategy; The model establishing unit is configured to establish a geometric model of the overall observation strategy and the separate observation strategy, respectively; The determining unit is configured to determine observation time points of the cluster target on the travel trajectory based on an observation interval; The echo data generating unit is configured to, for each current observation time point, perform: updating a model parameter of the current observation time point based on an observation strategy corresponding to the current observation time point, to generate electromagnetic scattering echo data of the current observation time point according to the updated model parameter; The echo data generating unit is further configured to generate electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data of each observation time point. When generating electromagnetic scattering echo data corresponding to the travel trajectory based on the electromagnetic scattering echo data at each observation time, the echo data generation unit is specifically used to extract the target's attitude angle change period using the AMDF method. For each observation time before The time interval corresponding to the duration is calculated to obtain the first RCS sequence; the median value of the first RCS sequence is calculated; for each... Curve fitting is performed on the maximum value in the duration; the data between adjacent observation times is filled based on the fitted curve to obtain the second RCS sequence, and the filled data is adjusted according to the fitted curve based on the median value to obtain the adjusted electromagnetic scattering echo data; The echo data generation unit is specifically configured to adjust the filled data according to the fitting curve according to the median value, and obtain adjusted electromagnetic scattering echo data according to the following formula : wherein, is the maximum value of the data in the time interval, is the sequence of maximum values of the data in the time interval, is the median value, is the value of the fitting curve corresponding to each time instant i, is the second RCS sequence. 7.An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the method of any one of claims 1-5 when executing the computer program. 8.A computer readable storage medium, having a computer program stored thereon, wherein the computer program, when executed in a computer, causes the computer to perform the method of any one of claims 1-5.

Images