Space target T / R-R type radar imaging system station layout optimization method and system

Abstract

The present invention discloses a method and system for optimizing the station layout of a space target T / R-R type radar imaging system. The method includes determining the prior information of the space target; based on the prior information of the space target, determining the monostatic ISAR imaging plane when the T / R station observes alone; determining the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode; taking the minimum angle formed between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane as the objective, establishing a station layout optimization function; solving the station layout optimization function to determine the optimal deployment position of the R station. The present invention takes the minimum angle between the two imaging planes as the objective function, solves to determine the optimal deployment position of the receiving station R station. The angle between the two imaging planes is as small as possible, effectively expanding the spatial spectral domain, improving the data fusion efficiency, and further improving the lateral resolution of the T / R-R type radar imaging system, which can provide theoretical support for improving the fusion imaging quality of the T / R-R type radar imaging system.

Description

Technical Field

[0001] The present invention relates to the technical field of radar imaging system optimization, and particularly to a method and system for optimizing the station layout of a space target T / R-R type radar imaging system. Background Art

[0002] The T / R-R radar system is a composite radar system that combines a monostatic radar and a bistatic radar. It consists of a transmitter and two separated receiving mechanisms, with one of the receivers co-located with the transmitter. The bistatic radar has the characteristics of strong anti-electronic interference, anti-strike, and good concealment. Therefore, the T / R-R radar system will have the advantages of both monostatic and bistatic radars, not only improving the target detection and tracking capabilities, but also having flexible system deployment, and further expanding the detection range, thus attracting wide attention.

[0003] For the existing monostatic / bistatic ISAR imaging of space targets, since the radar imaging plane is not coplanar with the target orbit plane, during long-term observation, the normal vector of the imaging plane is not constant. The resulting three-dimensional rotation (yaw, pitch, roll) of the imaging plane increases the difficulty of transverse focusing of the ISAR echo, reducing the effective accumulation angle caused by the change of the radar line of sight in the non-ideal arc segment. To achieve the same resolution, the coherent accumulation time will increase. To improve the imaging efficiency and quality, usually, the imaging time period will be carefully selected. Within this limited imaging segment, the normal vector of the radar imaging plane should be kept as constant as possible. If, within this imaging segment, the observations from multiple radars with different perspectives can be effectively utilized simultaneously, it will undoubtedly bring great benefits to improving the transverse resolution. The idea of fusing the observation data of multiple radars for the same target to improve the image quality, signal-to-noise ratio, or obtain higher resolution has a long history. And previous related research has also shown that by using the observation angle difference of multiple spatially separated radars for the same target, under the premise of appropriate data preprocessing, an equivalent wide aperture can be obtained in a shorter observation time to improve the transverse resolution, which has gradually become a research hotspot among many scholars at home and abroad.

[0004] The existing R station and T / R station form a bistatic ISAR working mode, which makes full use of the inherent advantages of the bistatic ISAR and can also fuse the echoes received by the two radars for imaging, increasing the available information for imaging and providing a way to improve the transverse resolution of space targets.

[0005] The essence of improving the transverse resolution of the T / R-R type radar imaging system is to equivalently broaden the spatial spectral domain formed by the radar's observation of the target. However, the effective spectral domain expansion is closely related to the radar station layout. In view of this, in order to improve the fusion efficiency, the present invention studies an optimized station layout method for off-site observation of the R station. Summary of the Invention

[0006] To solve the above technical problems, the technical solution adopted by the present invention is to provide a method for optimizing the station layout of a space target T / R-R type radar imaging system, including the following steps:

[0007] Determine the prior information of the space target; based on the prior information of the space target, determine the monostatic ISAR imaging plane when the T / R station observes alone; determine the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode; taking the minimum angle formed between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane as the goal, establish a station layout optimization function; solve the station layout optimization function to determine the optimal deployment position of the R station; wherein,

[0008] The prior information of the space target includes the known orbit information of the space target.

[0009] The present invention also provides a station layout optimization system for a space target T / R-R type radar imaging system, including

[0010] An information acquisition unit: used to acquire the prior information of the space target, including the known orbit information of the space target;

[0011] A bistatic ISAR imaging plane calculation unit: based on the prior information of the space target, determine the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode;

[0012] A monostatic ISAR imaging plane calculation unit: based on the bistatic ISAR imaging plane calculated and determined by the bistatic ISAR imaging plane calculation unit, calculate and determine the monostatic ISAR imaging plane when the T / R station observes alone;

[0013] A model establishment unit: taking the minimum angle formed between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane as the goal, establish a station layout optimization function;

[0014] A station layout determination and output unit: solve the station layout optimization function to determine the optimal deployment position of the receiving station.

[0015] The present invention studies the method for optimizing the off-site observation and station layout of the T / R-R type radar imaging system, utilizes the known orbit information of the space target, according to the ISAR imaging plane when the T / R station observes alone and the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode, taking the minimum angle between the two imaging planes as the objective function, solves and determines the optimal deployment position of the receiving station R station, and the angle between the two imaging planes is as small as possible, so as to effectively expand the spatial spectral domain, improve the data fusion efficiency, and further improve the lateral resolution of the T / R-R type radar imaging system, which can provide theoretical support for improving the fusion imaging quality of the T / R-R type radar imaging system.

[0016] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a flowchart of the method of the present invention;

[0019] Figure 2 It is a flowchart of the specific steps for implementing the method of the present invention;

[0020] Figure 3 It is a diagram of the planar geometric relationship of bistatic ISAR imaging of the present invention;

[0021] Figure 4 It is the ISAR imaging plane (a) and the spatial spectral domain (b) of the present invention;

[0022] Figure 5 It is a system block diagram provided by the present invention;

[0023] Figure 6 It is a schematic diagram of the structure of a computer device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0026] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined. In addition, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The working idea of the present invention to achieve system optimized station layout is as follows:

[0028] In a T / R-R type radar imaging system, when ISAR imaging uses the range-Doppler principle for imaging, the radar obtains the range direction of the target by transmitting a broadband LFM signal, obtains the azimuth direction through Doppler analysis, and the range direction and the Doppler direction together form the imaging plane. The ISAR imaging result is the mapping display of the actual target on the imaging plane. The present invention starts from bistatic ISAR, uses the known orbit information of the space target, first analyzes the imaging plane of the bistatic ISAR turntable model, and then, for the actual situation of a three-axis stabilized space target, studies this kind of target with both rotation and smooth movement, and gives a method for determining its imaging plane. Monostatic ISAR is a special form of bistatic ISAR. According to the method for determining the imaging plane of bistatic ISAR, the method for determining the imaging plane of monostatic ISAR is further deduced. Finally, according to the angle between the two imaging planes, the smaller the angle, the more it promotes the fusion imaging efficiency of the T / R-R type radar imaging system. An objective function is established with the angle between the two imaging planes to solve and determine the optimal deployment position of the receiving station R station.

[0029] The following makes a detailed description of the present invention in combination with the specific embodiments and the accompanying drawings of the specification.

[0030] Method Embodiment

[0031] According to an embodiment of the present invention, there is provided a method for optimizing the station layout of a space target T / R-R type radar imaging system, as Figure 1 shown, which is a flowchart of the method for optimizing the station layout of a space target T / R-R type radar imaging system provided by this embodiment. The method includes:

[0032] Determine the prior information of the space target; include the known orbit information of the space target; based on the prior information of the space target, determine the monostatic ISAR imaging plane when the T / R station observes alone; determine the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode; with the goal of minimizing the angle formed by the bistatic ISAR imaging plane and the monostatic ISAR imaging plane, establish a station layout optimization function; solve the station layout optimization function to determine the optimal deployment position of the receiving station.

[0033] This embodiment studies the method for optimizing the station layout of the T / R-R type radar imaging system for off-site observation. Using the known orbit information of the space target, according to the ISAR imaging plane when the T / R station observes alone and the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode, with the minimum angle between the two imaging planes as the objective function, solve to determine the optimal deployment position of the receiving station R. The angle between the two imaging planes is as small as possible, so as to effectively expand the spatial spectral domain, improve the data fusion efficiency, and further improve the lateral resolution of the T / R-R type radar imaging system, which can provide theoretical support for improving the fusion imaging quality of the T / R-R type radar imaging system.

[0034] This embodiment preferably, as Figure 2 shown, the method of this embodiment specifically includes the following steps:

[0035] Step 1: Determine the prior information of the space target;

[0036] Step 2: According to the prior information of the space target, determine the range direction and azimuth direction of the monostatic ISAR imaging plane when the T / R station observes alone, and determine the normal direction of the monostatic ISAR imaging plane;

[0037] Step 3: Determine the range direction and azimuth direction of the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode, and determine the normal direction of the bistatic ISAR imaging plane;

[0038] Step 4: Calculate the angle between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane

[0039] Step 5: Take the position where the receiving station is distributed on the normal line of the monostatic ISAR imaging plane as the traversal path, and change the position of the receiving station on the normal line according to the set step size, and execute Steps 3 to 4 until the traversal ends;

[0040] Step 6: Determine the minimum value, which is the optimal station layout position; because when is the smallest, the position of the R station corresponding to it is the optimal station layout position.

[0041] It should be noted that the R station (receiving station) should perform traversal search on a certain normal line of the monostatic ISAR imaging plane. The search step is determined according to the actual situation. The smaller the step size, the more accurate the optimal station layout position, but the larger the computational amount. On the contrary, the larger the step size, the rougher the optimal station layout position, but the smaller the computational amount.

[0042] Preferably in this embodiment, steps 2 to 3 are specifically as follows:

[0043] According to the prior information of the space target, determine the range direction and azimuth direction of the bistatic ISAR imaging plane under the space target turntable model, and determine the normal direction of the imaging plane;

[0044] Determine the range direction and azimuth direction of the monostatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane.

[0045] Determine the range direction and azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane;

[0046] 1) According to the prior information of the space target, determine the range direction and azimuth direction of the bistatic ISAR imaging plane under the space target turntable model, and determine the normal direction of the imaging plane. The calculation and solution process is as follows:

[0047] As Figure 2 shown, it is the geometric relationship diagram of the ISAR imaging plane under the bistatic turntable model. Taking the center of the space target as the origin O, a right-handed rectangular coordinate system xyz in space is constructed, where the x-axis points from the center of the space target to the transmitting station, the y-axis is in the bistatic plane and perpendicular to the x-axis, and the z-axis forms a right-handed coordinate system with the x-axis and y-axis. The space target rotates around the origin O in the xyz coordinate system, and its rotation vector is ω ∑ ; Denote R T as the unit vector in the line-of-sight direction of the transmitting station radar, that is, the unit vector of the x-axis, and R R as the unit vector in the line-of-sight direction of the receiving station radar.

[0048] For a certain scattering point A on the space target, its position vector is r. The velocity vector V generated by the rotation of the scattering point A due to the rotation of the space target is as follows:

[0049] V = ω ∑ ×r (21)

[0050] In the formula, "×" represents cross product;

[0051] In the bistatic ISAR imaging plane, the Doppler generated by the rotation of each scattering point of the space target is the sum of the Doppler of the scattering point relative to the transmitting station and the receiving station; then the Doppler generated by the scattering point relative to the transmitting and receiving stations is as follows:

[0052]

[0053] Substituting Equation (21) into Equation (22) and using the mixed product formula \((\vec{a}\times\vec{b})\cdot\vec{c}=\vec{a}\cdot(\vec{b}\times\vec{c})\), we get

[0054]

[0055] Let the actual rotation vector be \(\vec{\omega}\) ∑ The projections of \(\vec{\omega}\) on the orthogonal planes of the radar line of sight at the transmitting station and the receiving station are \(\vec{\omega}_{1}\) T and \(\vec{\omega}_{2}\) R respectively. Then

[0056] \(\vec{R}_{1}\) T \(\times\vec{\omega}_{1}\) ∑ =\(\vec{R}_{2}\) T \(\times\vec{\omega}_{2}\) T , \(\vec{R}_{2}\) R \(\times\vec{\omega}_{2}\) ∑ =\(\vec{R}_{3}\) R \(\times\vec{\omega}_{3}\) R (24)

[0057] Substituting Equation (24) into Equation (23), we get

[0058]

[0059] It can be seen that in the bistatic ISAR imaging plane, the Doppler value of the scatterer is the projection of the scatterer position vector \(\vec{r}\) in the direction of \((\vec{R}_{1}\) T \(\times\vec{\omega}_{1}\) T +\(\vec{R}_{2}\) R \(\times\vec{\omega}_{2}\) R ). That is, \((\vec{R}_{1}\) T \(\times\vec{\omega}_{1}\) T +\(\vec{R}_{2}\) R \(\times\vec{\omega}_{2}\) R ) is the azimuth direction of the bistatic ISAR imaging plane; the range direction is the gradient vector of the equidistant surface of the bistatic ISAR imaging plane. Since the equidistant surface of the bistatic radar is an ellipse with the two stations as the two foci, the direction of its gradient vector is the angular bisector direction, which is the direction of \((\vec{R}_{1}\) T +\(\vec{R}_{2}\) R ). Therefore, the range of the bistatic ISAR imaging plane is as follows:

[0060] \(\Theta=\vec{R}_{1}\) T +\(\vec{R}_{2}\) R (26)

[0061] The azimuth direction of the bistatic ISAR imaging plane is as follows:

[0062] \(\Xi=-(\vec{R}_{1}\) T \(\times\vec{\omega}_{1}\) T +\(\vec{R}_{2}\) R \(\times\vec{\omega}_{2}\) R ) (27)

[0063] In the formula, the positive or negative values of Θ and Ξ do not affect the determination of the imaging plane. For the bistatic ISAR imaging plane under the turntable model, since in the azimuth direction Ξ = -(R T +R R )×ω ∑ =-Θ×ω ∑ , the azimuth direction of the imaging plane is always orthogonal to the range direction.

[0064] 2) Determine the range direction and azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane. The calculation and solution process are as follows:

[0065] The imaging plane of the bistatic ISAR was analyzed based on the turntable model above. For a three-axis stabilized space target, there are both translational motion and its own rotation. The translational motion of the target will cause changes in the viewing angle difference relative to the transceiver radar, which will in turn affect the Doppler of the scatter points. Therefore, the imaging plane of the three-axis stabilized space target is jointly determined by the translational motion and its own rotation of the target;

[0066] Set the velocity vector of the centroid of the three-axis stabilized space target in orbit operation as v. The radial velocity of the target relative to the transceiver radar does not cause changes in the radar viewing angle. The velocity components in the tangential direction of the transmitting station radar line of sight and the receiving station radar line of sight (i.e., the projections of the motion velocity on the normal plane of the transmitting station and receiving station radar line of sight directions) are v T 、v R , respectively. Then the following formula is satisfied:

[0067] v×R T =v T ×R T ,v×R R =v R ×R R (28)

[0068] Since during radar imaging, after motion compensation, the translational component of the target is compensated, and it is transformed into turntable imaging. Therefore, the total rotation vector of the three-axis stabilized space target consists of two parts: the rotation vector caused by the translational motion of the target and the rotation vector generated by the target attitude stability; Set the rotation vectors of the target translational motion relative to the transmitting station and receiving station radars as ω vT 、ω vR , respectively. Then

[0069]

[0070] In the formula, R T 、R R are the distances from the centroid of the space target to the transmitting station and receiving station radars, respectively. Set the rotation vector of the three-axis stabilized space target's own rotation as ω s , and its projections ω sT 、ωsR Satisfy the following formula:

[0071] R T ×ω s =R T ×ω sT ,R R ×ω s =R R ×ω sR (30)

[0072] Let the total rotation vectors of the space target relative to the radar of the launching station and the receiving station be ω ∑T 、ω ∑R , respectively, then

[0073] ω ∑T =ω sT +ω vT ,ω ∑R =ω sR +ω vR (31)

[0074] Substitute ω ∑T 、ω ∑R in formula (31) into ω T 、ω R in formula (27) respectively, and combine with formulas (29) and (30), the azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target can be calculated as follows:

[0075]

[0076] From the vector product formula a×b×c=(a·c)b-(b·c)a, it can be obtained that

[0077] R T ×v T ×R T =(R T ·R T )v T -(v T ·R T )R T =v T (33)

[0078] R R ×v R ×R R =(R R ·R R )v R -(v R ·R R )R R =v R (34)

[0079] Therefore, the azimuth ξ of the bistatic ISAR imaging plane of a three-axis stabilized space target can be determined by the following formula

[0080]

[0081] Let ξ1 = R T × ω sT + R R × ω sR , ξ2 = v T / R T + v R / R R , then ξ1 is the azimuth vector generated in the case of the turntable, and ξ2 is the azimuth vector caused by the translational motion of the target

[0082] For the bistatic radar, the range direction θ of the bistatic ISAR imaging plane of a three-axis stabilized space target Bi is still the angular bisector direction, that is

[0083] θ Bi = R T + R R (36)

[0084] Since the space target can be regarded as a cooperative target, the orbital position and velocity vector information at any time can be obtained from the provided orbital elements. The azimuth and range directions at each imaging moment can be obtained from equations (35) and (36). The azimuth and range directions jointly determine the instantaneous imaging plane of the bistatic ISAR, as follows

[0085] The normal ψ2 of the bistatic ISAR imaging plane can be obtained by cross-multiplying the above azimuth and range directions, that is

[0086] ψ2 = θ Bi × ξ Bi (37)

[0087] 3) According to the solution of the above bistatic ISAR imaging plane, determine the range and azimuth of the monostatic ISAR imaging plane of a three-axis stabilized space target, and determine the normal of the imaging plane. The calculation and solution process is as follows

[0088] Since the monostatic ISAR is a special form of the bistatic ISAR, based on the method for determining the bistatic ISAR imaging plane, this embodiment gives the method for determining the imaging plane of the monostatic ISAR

[0089] For the monostatic radar, the range direction θ of the monostatic ISAR imaging plane of a three-axis stabilized space target Si is the radar line-of-sight direction. Referring to equation (36), the range direction θ of the monostatic ISAR imaging plane of a three-axis stabilized space target Si is as follows

[0090] Θ Si = R T (38)

[0091] Referring to the bistatic ISAR azimuth determination method in Equation (35), the azimuth Ξ of the monostatic ISAR imaging plane of a three-axis stabilized space target Si is only related to the transmitting station and can be determined by the following formula:

[0092]

[0093] The normal vector ψ1 of the monostatic ISAR imaging plane of a three-axis stabilized space target can be obtained by the cross product of the azimuth and range directions, that is

[0094] ψ1 = Θ Si × Ξ Si (40)

[0095] Based on the normal vector ψ2 of the bistatic ISAR imaging plane of the three-axis stabilized space target and the normal vector ψ1 of the monostatic ISAR imaging plane of the three-axis stabilized space target obtained above, the angle between the monostatic and bistatic ISAR imaging planes can be calculated and determined as follows.

[0096] The essence of improving the cross-range resolution by the fusion imaging of the T / R-R type radar system is to equivalently broaden the spatial spectral domain formed by the radar's observation of the target. However, the effective spectral domain expansion is closely related to the radar station layout. To improve the fusion efficiency, an optimized station layout method for the R station's off-site observation is studied.

[0097] As Figure 4 shown, it is the imaging plane and spatial spectral domain distribution diagram of the T / R station and the R station during the T / R-R type radar imaging. A spatial rectangular coordinate system xyz is established with the imaging plane of the T / R station radar as the xoy plane. Let the angle between the monostatic and bistatic ISAR imaging planes be Since the ISAR two-dimensional imaging is the mapping of the target on the imaging plane, in order to effectively fuse the images, the ideal requirement is that the projections of the same scattering point on the target on the two imaging planes coincide.

[0098] For the T / R station radar, the spatial spectral domain of its received signal is in the f x ~ f y plane, as Figure 4 (b) The circular ring cut region S1:

[0099]

[0100] where B is the bandwidth of the transmitted linear frequency modulation signal, and θ m is the cumulative rotation angle corresponding to the mth pulse of the T / R station radar during the imaging observation period;

[0101] For the R-site radar, since the imaging plane for receiving the echo is not coplanar with that of the T / R-site radar and there is a bistatic angle, i.e., β≠0, its spatial spectral domain is no longer in the f x ~f y two-dimensional plane, but in the three-dimensional f x ~f y ~f z space:

[0102]

[0103] Its projection onto the f x ~f y two-dimensional plane is Figure 4 (b) the circular ring cut region S2'. It can be seen that the two spectral planes formed by the ISAR imaging of the T / R-site and R-site cannot effectively coincide into one plane. If the conventional spectral domain data coherence processing method is directly used, the complex situation of the three-dimensional to two-dimensional projection caused by f z must be processed. In particular, when , f x = 0, f y = 0, that is, when the observation vector formed by the R-site is orthogonal or nearly orthogonal to the T / R-site, the two-dimensional spatial spectral plane cannot be extended at all; conversely, when the bistatic angle β is very small and , the spatial spectral domain of the R-site radar received signal is Figure 4 (b) the circular ring cut region S2. At this time, the two independent spectral domains S1 and S2 can be maximally fused into a two-dimensional spectral plane. Therefore, in order to better fuse the echo data of the two stations, it is required that the distance between the two stations cannot be too far to ensure that the bistatic angle is not too large. In addition, ideal station layout is also required to make the included angle as small as possible, so as to bring about an effective expansion of the spatial spectral domain.

[0104] Then the included angle can be expressed as:

[0105]

[0106] Different R-site positions correspond to different included angles After traversing the positions of the R-site in a traversal manner, the R-site position corresponding to the minimum included angle is the optimal station layout position.

[0107] System embodiment

[0108] According to an embodiment of the present invention, there is provided a spatial target T / R-R type radar imaging system station layout optimization system based on the above-mentioned spatial target T / R-R type radar imaging system station layout optimization method, as Figure 5As shown in the figure, this is the station layout optimization system for the space target T / R-R type radar imaging system provided by this embodiment. This system includes

[0109] Information acquisition unit: used to acquire the prior information of the space target, including the known orbit information of the space target;

[0110] Monostatic ISAR imaging plane calculation unit: Based on the bistatic ISAR imaging plane calculated and determined by the bistatic ISAR imaging plane calculation unit, calculate and determine the monostatic ISAR imaging plane when the T / R station observes alone;

[0111] Bistatic ISAR imaging plane calculation unit: Based on the prior information of the space target, determine the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic manner; specifically including

[0112] Model establishment unit: Taking the minimum angle formed by the bistatic ISAR imaging plane and the monostatic ISAR imaging plane as the goal, establish a station layout optimization function;

[0113] Station layout determination and output unit: Solve the station layout optimization function to determine the optimal deployment position of the receiving station.

[0114] In this embodiment, preferably, the station layout determination and output unit includes a traversal module: used to repeatedly call the station layout optimization function in the bistatic ISAR imaging plane calculation unit and the model establishment unit according to the set traversal conditions and the set step size until the traversal is completed.

[0115] The preferably traversal condition of the traversal module is: taking the position where the receiving station is distributed on the normal line of the monostatic ISAR imaging plane as the traversal path, and changing the position of the receiving station on the normal line according to the set step size.

[0116] In this embodiment, preferably,

[0117] The specific calculation of the monostatic ISAR imaging plane calculation unit includes: According to the prior information of the space target, determine the range direction and azimuth direction of the monostatic ISAR imaging plane when the T / R station observes alone, and determine the normal direction of the monostatic ISAR imaging plane;

[0118] The specific calculation of the bistatic ISAR imaging plane calculation unit includes: Determine the range direction and azimuth direction of the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic manner, and determine the normal direction of the bistatic ISAR imaging plane;

[0119] The station layout optimization function established according to the bistatic ISAR imaging plane and the monostatic ISAR imaging plane is specifically as follows:

[0120]

[0121] That is, calculate the angle between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane When the angle formed by the bistatic ISAR imaging plane and the monostatic ISAR imaging plane is the smallest, the point of the current R station (receiving station) on a certain normal line of the monostatic ISAR imaging plane is the optimal station layout position.

[0122] The embodiments of the present invention are system embodiments corresponding to the above method embodiments. Each calculation step can be understood with reference to the description of the method embodiments and will not be elaborated here.

[0123] As Figure 6 shown, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for optimizing the station layout of the space target T / R-R type radar imaging system in the above embodiments, or when the computer program is executed by a processor, it implements the method for optimizing the station layout of the space target T / R-R type radar imaging system in the above embodiments.

[0124] Those of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0125] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for the device or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0126] It should be noted that in this text, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0127] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. Space target T / R-R type radar imaging system station layout optimization method, characterized in that It includes the following steps: Determine the prior information of the space target; Based on the prior information of the space target, determine the monostatic ISAR imaging plane when the T / R station observes alone; Determine the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode; aiming at minimizing the included angle between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane, establish a station layout optimization function; solve the station layout optimization function to determine the optimal deployment position of the R station; wherein, The prior information of the space target includes the known orbit information of the space target; The specific implementation steps are as follows: Step 1, determine the prior information of the space target; Step 2, according to the prior information of the space target, determine the range direction and azimuth direction of the monostatic ISAR imaging plane when the T / R station observes alone, and determine the normal direction of the monostatic ISAR imaging plane; Step 3, determine the range direction and azimuth direction of the bistatic ISAR imaging plane when the T / R station and the R station observe in a bistatic mode, and determine the normal direction of the bistatic ISAR imaging plane; Step 4, calculate the angle between the bistatic ISAR imaging plane and the monostatic ISAR imaging plane Step 5, take the position where the receiving station is distributed on the normal line of the monostatic ISAR imaging plane as the traversal path, and change the position of the receiving station on the normal line according to the set step size, and execute Step 3 to Step 4 until the traversal ends; Step 6. Determine the minimum value, which is the optimal station layout position; The specific content of the said Step 2 to Step 3 is as follows: According to the prior information of the space target, determine the range direction and azimuth direction of the bistatic ISAR imaging plane under the space target turntable model, and determine the normal direction of the imaging plane; Determine the range direction and azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane; Determine the range direction and azimuth direction of the monostatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane; The calculation and solution process of determining the range direction and azimuth direction of the bistatic ISAR imaging plane under the space target turntable model according to the prior information of the space target and determining the normal direction of the imaging plane is as follows: Taking the center of the space target as the origin O, a right-handed rectangular coordinate system xyz is constructed in space, where the x-axis points from the center of the space target to the launch station, the y-axis is in the bistatic plane and perpendicular to the x-axis, and the z-axis forms a right-handed coordinate system with the x-axis and y-axis. The space target rotates around the origin O in the xyz coordinate system, and its rotation vector is ω∑; is the unit vector in the line-of-sight direction of the radar at the launch station, is the unit vector in the line-of-sight direction of the radar at the receiving station; For a certain scattering point A on the space target, its position vector is r, and the velocity vector V generated by the rotation of the scattering point A due to the rotation of the space target is as follows: V = ω ∑ × r (1) In the formula, "×" represents cross product; The Doppler generated by the scattering point relative to the transceiver bistatic station is as follows: Substitute Equation (1) into Equation (2), and according to the mixed product formula (a×b)·c = a·(b×c), we can get Let the actual rotation vector be ω ∑ The projections of ω on the orthogonal planes of the radar line of sight at the transmitting station and the receiving station are ω T and ω R respectively. Then Substitute Equation (4) into Equation (3) to get The range of the bistatic ISAR imaging plane is as follows: The azimuth direction of the bistatic ISAR imaging plane is as follows: The determination of the range direction and azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target and the determination of the normal direction of the imaging plane include calculation steps: Set the velocity vector of the centroid of the three-axis stabilized space target in orbital motion as v, and the velocity components in the tangential direction of the radar line of sight at the launch station and the tangential direction of the radar line of sight at the receiving station are v T and v R , respectively. Then the following equation is satisfied: The rotation vectors generated by setting the target translational motion with respect to the radar of the transmitting station and the receiving station are ω vT and ω vR respectively. where, R T , R R are the distances from the centroid of the space target to the radars of the launch station and the receiving station respectively. Let the rotation vector of the self-rotation of the three-axis stabilized space target be ω s , and its projections ω sT , ω sR on the normal planes of the line-of-sight directions of the radars of the launch station and the receiving station satisfy the following equation: Let the total rotation vectors of the space target relative to the radars of the launching station and the receiving station be ω ∑T and ω ∑R respectively. Then ω ∑T = ω sT + ω vT , ω ∑R = ω sR + ω vR (11) Substitute ω in Equation (11) ∑T and ω ∑R into ω in Equation (7) T and ω R respectively, and combine with Equations (9) and (10) to calculate the azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target, as shown in the following equation: From the vector product formula a×b×c = (a·c)b - (b·c)a, we can get Therefore, the azimuth direction Ξ of the bistatic ISAR imaging plane of the three-axis stabilized space target is: Let Ξ2 = v T / R T + v R / R R where Ξ1 is the azimuth vector generated in the case of the turntable, and Ξ2 is the azimuth vector caused by the translational motion of the target; For a bistatic radar, the range direction Θ of the bistatic ISAR imaging plane of a three-axis stabilized space target Bi is still the angular bisector direction, that is The normal direction ψ2 of the bistatic ISAR imaging plane can be obtained by cross multiplying the above azimuth direction and range direction, that is ψ2 = Θ Bi × Ξ Bi (17); The range direction of the monostatic ISAR imaging plane of the three-axis stabilized space target is as follows: Azimuth direction Ξ of the imaging plane of a three-axis stabilized space target monostatic ISAR Si As follows: The normal direction ψ1 of the monostatic ISAR imaging plane of the three-axis stabilized space target is as follows ψ1 = Θ Si × Ξ Si (20); The station layout optimization function is: Different positions of the R station correspond to different included angles After the traversal of the positions of the R station is ended by means of traversal, the included angle The position of the R station corresponding to the minimum is the optimal station layout position.

2. A system for implementing the method for optimizing the station layout of a spatial target T / R-R type radar imaging system as described in claim 1, characterized in that, It includes Information acquisition unit: used to acquire prior information of a space target, including known orbit information of the space target; Bistatic ISAR imaging plane calculation unit: based on the prior information of the space target, determine the bistatic ISAR imaging plane during the bistatic observation of the T / R station and the R station; Monostatic ISAR imaging plane calculation unit: based on the bistatic ISAR imaging plane calculated and determined by the bistatic ISAR imaging plane calculation unit, calculate and determine the monostatic ISAR imaging plane during the individual observation of the T / R station; Model establishment unit: with the goal of minimizing the included angle formed by the bistatic ISAR imaging plane and the monostatic ISAR imaging plane, establish a station layout optimization function; Station layout determination and output unit: solve the station layout optimization function to determine the optimal deployment position of the receiving station; The specific calculation of the bistatic ISAR imaging plane calculation unit includes: determining the range direction and azimuth direction of the bistatic ISAR imaging plane during the bistatic observation of the T / R station and the R station, and determining the normal direction of the bistatic ISAR imaging plane; According to the prior information of the space target, determine the range direction and azimuth direction of the bistatic ISAR imaging plane under the space target turntable model, and determine the normal direction of the imaging plane; determine the range direction and azimuth direction of the bistatic ISAR imaging plane of the three-axis stabilized space target, and determine the normal direction of the imaging plane.

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