Low-altitude target positioning-oriented airborne phased array radar resource management method and system

Abstract

The invention provides an airborne phased array radar resource management method for low-altitude target positioning, and belongs to the field of radars. Comprising the following steps: S1, calculating a minimum clutter-free bandwidth based on prior information of a low-altitude target; s2, establishing an airborne phased array radar resource management model for low-altitude target positioning by taking maximized radar revenue as an objective function and taking minimum clutter-free bandwidth, target positioning precision, radar aperture and total power as constraint conditions; and S3, defining a cost performance function according to the target revenue and the resource consumption, optimizing the target selection and power distribution of the airborne phased array radar by using a greedy algorithm, and obtaining a resource distribution scheme for maximizing the radar revenue. According to the method, the minimum clutter-free bandwidth is calculated and allocated, so that ground clutters are filtered out in a time domain when a target is positioned; a resource allocation strategy for maximizing radar income is provided, the contradiction between resource limitation and multiple target positioning task requirements is balanced, radar target selection and power allocation are optimized, and the maximum income of the radar can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a method and system for managing airborne phased array radar resources for low-altitude target positioning. Background Art

[0002] Airborne phased array radar systems are an indispensable part of modern avionics due to their excellent beam agility and are widely used in military and civilian fields. Due to the limitations of the working environment, the radiation resources of airborne phased array radars are limited and need to be effectively managed. How to achieve efficient operation and performance optimization of radar systems under limited resource conditions has become an important research direction. Existing research has mostly focused on macro-level resource allocation optimization, improving resource utilization and radar performance by reasonably allocating resources such as power, bandwidth, waveform, radar nodes, and dwell time. For example, the patent publication number CN108333583A discloses a resource allocation method based on phased array radar search and tracking dual-target optimization. It obtains Pareto subsets by solving the convex minimax optimization problem in parallel, realizes effective resource allocation, and simplifies the resource allocation process.

[0003] However, there are still many problems to be solved in the positioning of specific targets, especially the precise positioning of low-altitude targets. With the development of technology, the number and application scope of low-altitude targets are constantly expanding, and the activities of these targets pose new challenges to aviation safety, military security, urban security and other fields. There are many unique problems in the positioning of low-altitude targets. The interference of clutter is more serious. Its signal is often covered by ground reflection or scattered clutter, resulting in a significant decrease in the signal-to-noise ratio. In addition, low-altitude targets have greater motion uncertainty due to their low flying altitude, which increases the complexity of positioning. When dealing with the positioning of low-altitude targets, the existing radar resource management strategies are usually difficult to balance the requirements of resource allocation and positioning accuracy under the constraints of limited hardware resources, which makes the positioning of low-altitude targets a special and urgent problem in radar resource management. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to balance the requirements of resource allocation and multi-target positioning tasks while suppressing clutter interference and improving positioning accuracy when using radar resource management strategies to deal with low-altitude target positioning.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an airborne phased array radar resource management method for low-altitude target positioning, comprising the following steps:

[0006] S1: Calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets, specifically:

[0007] S101: Divide the radar beam into m range resolution units, and the range resolution ΔR satisfies where m represents the number of range resolution cells, and D q is the distance from the radar to target q; is the distance between the radar and the ground in the beam direction for locating target q;

[0008] S102: Use the formula to calculate the minimum clutter - free bandwidth allocated for the radar to locate target q. c is the speed of light, and D q,g is the distance between target q and the ground in the beam direction for locating target q;

[0009] S2: Establish an airborne phased - array radar resource management model for low - altitude target location with maximizing the radar benefit as the objective function and the minimum clutter - free bandwidth, target location accuracy, radar aperture, and total power as the constraints;

[0010] S3: Define a cost - performance function based on target benefit and resource consumption, and use the greedy algorithm to optimize the target selection and power allocation of the airborne phased - array radar to obtain a resource allocation scheme that maximizes the radar benefit.

[0011] In the present invention, the radar beam is divided into multiple range resolution cells. By adjusting the size of the range resolution cells to cover only the target, the reflected signals from the ground can be filtered as much as possible, making the echo mainly composed of target signals. Determine the maximum range resolution cell and then determine the minimum clutter - free bandwidth. At this time, ensuring that the bandwidth allocated by the radar when locating the target is greater than the minimum clutter - free bandwidth can filter out ground clutter, which can greatly reduce the interference of ground clutter on the target location performance.

[0012] Preferably, in step S2, the airborne phased - array radar resource management model for locating Q low - altitude targets is as follows: where ω = [ω 1 , ω 2 , …, ω q , …, ω Q represents the target benefit vector, where ω q represents the benefit of the radar for locating the q - th target; represents maximizing the objective function ω by optimizing variables u, P, B, and N; C(ψ, N, P, B) is the Cramer - Rao lower - bound matrix, and ψ = [ψ 1 , ψ 2 , …, ψ q , …, ψ Q is the target position state vector, and its q - th element is ψ q = [x q , y q T , representing the position state of the q - th target, and x q , y q ​respectively represent the positions of the q-th target on the x-axis and y-axis in the two-dimensional plane; ε p represents the predetermined accuracy of target positioning; N = [N 1 , N 2 , …, N q , …, N Q is the radar aperture vector, and its q-th element is N q , representing the radar aperture allocated when the airborne phased array radar locates the q-th target; P = [P 1 , P 2 , …, P q , …, P Q is the power vector, and its q-th element is P q , representing the power transmitted when the phased array radar locates the q-th target; B = [B 1 , B 2 , …, B q , …, B Q is the bandwidth vector, and its q-th element is B q , representing the signal bandwidth allocated when the phased array radar locates the q-th target; u = [u 1 , u 2 , …, u q , …, u Q is the state vector, and u q represents whether the q-th target is located: when u q = 1, the power, bandwidth, and aperture allocated when locating target q are all positive; when u q = 0, the power, bandwidth, and aperture allocated when locating target q are all 0; B min,q represents the minimum clutter-free bandwidth of the q-th target; B total is the total bandwidth of the phased array radar; P total represents the total power of the phased array radar; N total is the total number of array elements of the phased array radar.

[0013] Preferably, the process of solving the Cramér-Rao lower bound matrix C(ψ, N, P, B) is as follows: According to time-delay positioning and direction-of-arrival positioning, solve the Fisher matrices respectively and combine them, and then invert the combined Fisher matrix to obtain the Cramér-Rao lower bound matrix C(ψ, N, P, B).

[0014] Preferably, the Fisher matrix solved according to time-delay positioning is where P q represents the power transmitted when the phased array radar locates the q-th target, B q represents the signal bandwidth allocated when the phased array radar locates the q-th target, and N q represents the radar aperture allocated when the airborne phased array radar locates the q-th target; where G is the radar gain, ξ q is the radar cross section of target q, D q is the distance from the radar to target q, is the variance of zero-mean Gaussian white noise, x q and y q respectively represent the positions of the q-th target on the x-axis and y-axis in the two-dimensional plane, x P and y P respectively represent the positions of the radar on the x-axis and y-axis in the two-dimensional plane.

[0015] Preferably, the Fisher matrix solved according to the direction-of-arrival positioning is In the formula where

[0016] Preferably, the Fisher matrix for joint time-delay positioning and direction-of-arrival positioning is J T-D (ψ q ) = J T (ψ q ) + J D (ψ q ). Inverting this Fisher matrix gives the Cramer-Rao lower bound matrix, that is, the Cramer-Rao lower bound matrix

[0017] Preferably, the process of step S3 is as follows:

[0018] S301: Set the cost performance of target q as where ω q represents the benefit of the radar for positioning the q-th target, D q is the distance from the radar to target q, D q,g is the distance between target q and the ground in the direction of target q. Calculate the cost performance of Q targets respectively and sort them from low to high, named as the target group;

[0019] S302: Select the Z targets with the highest cost performance and add them to the positioning group, Z < Q;

[0020] S303: Under the total bandwidth and total aperture resource constraints, optimize the power P, bandwidth B, and aperture N, and use the alternating iteration method to calculate the minimum total power required for positioning Z targets when meeting the positioning accuracy constraint conditions;

[0021] S304: If the minimum total power at this time is less than the total power P total of the radar, it means that the Z targets at this time are the effective positioning group. Otherwise, remove the target with the lowest cost performance from the positioning group in turn until the minimum total power required for the positioning group is less than the total power P total ;

[0022] S305: Select the target in the final effective positioning group as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

[0023] The present invention uses a greedy algorithm to optimize the target selection and power allocation of the airborne phased array radar under the constraints of the total bandwidth and total aperture resources, balances the contradiction between system resources and multi-target positioning requirements, while ensuring the positioning accuracy of multiple targets, consumes system resources as small as possible, and maximizes the radar benefit.

[0024] Preferably, in step S301, where k 1 is a constant greater than zero.

[0025] Preferably, the specific process of step S303 is as follows:

[0026] S303-1: Combine tr(C(ψ,N,P,B))≤ε p , obtain the total power objective function of power with respect to bandwidth and aperture P = f(B,N), and then combine Convert the equality constraint part into a penalty function and add it to the total power objective function to obtain the objective function f(P,B,N)=1 T P+(1 T B - B total ) 2 +(1 T N - N total ) 2 ;

[0027] S303-2: Uniformly allocate the aperture, and set the initial value of the aperture N k,opt allocated to Z targets in the positioning group as N 0 , that is, at this time N k,opt = N 0 ;

[0028] S303-3: Bandwidth optimization: Convert the power P into a function of the bandwidth B. At this time, the objective function is: Use the gradient descent method: where α is a constant representing the learning rate, and solve the optimal bandwidth allocation B k,opt in the positioning group for the k-th iteration;

[0029] S303-4: Aperture optimization: Let B = B k,opt , at this time the power P is a function of the aperture N, and the objective function is: Use the gradient descent method: Solve the optimal aperture allocation N k,opt in the positioning group for the k-th iteration;

[0030] S303-5: Substitute B k,opt and N k,opt into P = f(B, N) to solve for the optimal power allocation P for the k-th iteration k,opt .

[0031] The present invention also provides an airborne phased array radar resource management system for low-altitude target positioning, including the following modules:

[0032] Minimum clutter-free bandwidth calculation module: used to calculate the minimum clutter-free bandwidth based on the prior information of the low-altitude target, specifically including the following units:

[0033] Distance resolution determination unit: used to divide the radar beam into m distance resolution units, so that the distance resolution ΔR satisfies where D q is the distance from the radar to target q; is the distance between the radar and the ground along the direction of the beam of target q;

[0034] Minimum clutter-free bandwidth acquisition unit: used to calculate the minimum clutter-free bandwidth allocated for the radar to locate target q according to the formula where c is the speed of light, and D q,g is the distance between target q and the ground along the direction of the beam of the located target q;

[0035] Resource management model establishment module: used to establish an airborne phased array radar resource management model for low-altitude target positioning, with maximizing the radar benefit as the objective function and the minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as the constraint conditions;

[0036] Maximum benefit scheme acquisition module: used to define a cost-effective function according to the target benefit and resource consumption, and use the greedy algorithm to optimize the target selection and power allocation of the airborne phased array radar to obtain a resource allocation scheme that maximizes the radar benefit.

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] (1) By dividing the radar beam into multiple distance resolution units and adjusting their sizes so that they can only cover the target, the present invention can filter out the ground reflection signals as much as possible at this time, and the echo is mainly composed of target signals, improving the echo signal-to-noise ratio. After determining the maximum distance resolution of the radar when locating a certain target, the minimum clutter-free bandwidth at this time can be calculated. Ensuring that the bandwidth allocated for locating this target is greater than the minimum clutter-free bandwidth can effectively filter out clutter, greatly reducing the interference of ground clutter on the target positioning performance and making the target positioning more accurate;

[0039] (2) An airborne phased array radar resource management model is proposed with maximizing radar benefits as the objective function and target positioning accuracy, system hardware resources, and minimum clutter-free bandwidth as the constraint conditions. A cost-performance function defined based on target benefits and resource consumption is proposed under resource constraints. When facing the task requirements of multiple positioning targets, target selection is optimized according to the cost-performance ratio, and power allocation is further optimized under resource constraints, balancing the contradiction between system resources and multiple target positioning requirements. It can not only achieve the optimal selection of target positioning, ensure high-precision positioning of multiple targets, but also realize the reasonable allocation of radar resources at the same time, minimize the consumed system resources, and obtain the maximum radar benefits. Brief Description of the Drawings

[0040] Figure 1 It is the flowchart of Embodiment 1 of the present invention;

[0041] Figure 2 It is the scene diagram of the airborne phased array radar resource management for low-altitude target positioning in Embodiment 1 of the present invention;

[0042] Figure 3 It is the illustration diagram of the airborne phased array radar beam and range resolution in Embodiment 1 of the present invention. Detailed Embodiment

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] As Figure 1 shown, this embodiment provides an airborne phased array radar resource management method for low-altitude target positioning, including the following steps:

[0046] Step 1: Calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets, specifically:

[0047] As Figure 2 shown, assume that the airborne phased array radar is located at (x P , y P ) in the two-dimensional plane, and Q low-altitude targets are located at (x q , y q ), where q = 1, 2,..., Q.

[0048] Combined with Figure 3, when the airborne phased array radar locates these targets, it is often severely interfered by clutter. For intuitive analysis, the radar beam is simplified to a straight line. The beam consists of several range resolution cells. If the size of the range resolution cell is appropriately reduced so that it only covers the target, the ground reflection signal can be filtered as much as possible. At this time, the echo is mainly composed of the target signal, greatly reducing the interference of ground clutter on the target positioning performance. Therefore, it is proposed that the range resolution needs to meet: In the formula, m represents the number of range resolution cells; ΔR represents the range resolution of the radar; D q is the distance from the radar to target q; is the distance between the radar and the ground along the beam direction of the positioning target q.

[0049] Transform into Therefore, the range resolution ΔR should satisfy That is, ΔR ≤ D q,g , D q,g is the distance between target q and the ground along the beam direction of target q. Also, because c is the speed of light, B q represents the signal bandwidth allocated by the phased array radar to locate target q. Then there is Obtain the minimum clutter-free bandwidth When the bandwidth allocated for locating target q is greater than this minimum clutter-free bandwidth, the ground clutter can be filtered out.

[0050] Step 2: Establish an airborne phased array radar resource management model for low-altitude target positioning, specifically as follows:

[0051] When there are too many targets in the radar monitoring airspace, the radar cannot meet the requirements of all positioning targets. At this time, targets need to be selected. In this embodiment, the maximum radar benefit is used as the objective function, and the target positioning accuracy, system hardware resources, and minimum clutter-free bandwidth are used as constraint conditions to establish an airborne phased array radar resource management model for low-altitude target positioning: Among them, ω = [ω 1 , ω 2 , …, ω q , …, ω Q represents the target benefit vector, where ω q represents the benefit of the radar for positioning the qth target; represents maximizing the objective function ω by optimizing the variables u, P, B, and N; C(ψ, N, P, B) is the Cramer-Rao lower bound matrix, ψ = [ψ 1 , ψ 2 , …, ψ q , …, ψ Q is the target position state vector, and its qth element is ψ q = [x q, y q T , representing the position status of the q-th target, x q , y q respectively represent the positions of the q-th target on the x-axis and y-axis in the two-dimensional plane; ε p represents the predetermined accuracy of target positioning; N = [N 1 , N 2 , …, N q , …, N Q is the radar aperture vector, and its q-th element is N q , representing the radar aperture allocated when the airborne phased array radar locates the q-th target; P = [P 1 , P 2 , …, P q , …, P Q is the power vector, and its q-th element is P q , representing the power transmitted by the phased array radar when locating the q-th target; B = [B 1 , B 2 , …, B q , …, B Q is the bandwidth vector, and its q-th element is B q , representing the signal bandwidth allocated when the phased array radar locates the q-th target; u = [u 1 , u 2 , …, u q , …, u Q is the state vector, u q indicates whether the q-th target is located: u q = 1, the power, bandwidth, and aperture allocated when locating target q are all positive; u q = 0, the power, bandwidth, and aperture allocated when locating target q are all 0; B min,q represents the minimum clutter-free bandwidth of the q-th target; B total is the total bandwidth of the phased array radar; P total represents the total power of the phased array radar; N total is the total number of array elements of the phased array radar.

[0052] Among them, C(ψ, N, P, B) is the Cramer-Rao Lower Bound (CRLB), which is used to measure the positioning accuracy of the target and can be obtained by inverting the Fisher Information Matrix (FIM). According to the Time of Arrival (TOA) positioning, its FIM is: Among them, ψ q = [x q , y q ​​T , representing the position state of the q-th target, τ q represents the time delay.

[0053] Therefore, the Jacobian matrix can be expressed as: Using α q and β q to represent the elements in the matrix, and the two are defined as: where c is the speed of light, x q , y q respectively represent the positions of the q-th target on the x-axis and y-axis in the two-dimensional plane, x P , y P respectively represent the positions of the radar on the x-axis and y-axis in the two-dimensional plane. Substituting into gives: where In the formula, G is the radar gain, ξ q is the Radar Cross Section (RCS) of the q-th target, is the variance of zero-mean Gaussian white noise.

[0054] Similarly, when using Direction of Arrival (DOA) for positioning, its FIM is where In the formula, and

[0055] Thus, the FIM for joint TOA and DOA positioning is: J T-D (ψ q ) = J T (ψ q ) + J D (ψ q ). Therefore, the CRLB matrix is:

[0056] Step 3: Define the cost performance function according to the target benefit and resource consumption, and use the greedy algorithm to obtain the maximum radar benefit, specifically:

[0057] In order to select the target with a greater radar system benefit among many targets, this embodiment uses the cost performance to measure the positioning priority of the target. The cost performance can be expressed as the ratio of the benefit of positioning the target to the expected consumption. The benefit of positioning the target is: In the formula, k 1 is a constant greater than zero, and D q is the distance between the radar and the target q.

[0058] The above formula shows that the gain decreases as the distance between the target and the radar increases. The expected resource consumption can be measured from two aspects: on the one hand, when the target is closer to the ground along the beam direction, higher range resolution is required to distinguish the target from the ground, which means a larger bandwidth is needed at this time; on the other hand, when the target is farther away from the radar, more resources are required to achieve the positioning accuracy. Therefore, considering the above two factors, the cost performance of the target is expressed as Based on this formula, prioritize the positioning of targets with high cost performance rankings to maximize the radar gain as much as possible.

[0059] The specific process of using the greedy algorithm to obtain the maximum radar gain is as follows:

[0060] S301: Use the formula Calculate the cost performance of Q targets respectively and sort them from low to high, named as the target group;

[0061] S302: Select the Z targets with the highest cost performance and add them to the positioning group, where Z < Q;

[0062] S303: Under the constraints of the total bandwidth and total aperture resources, optimize the power P, bandwidth B, and aperture N, and use the alternating iteration method to calculate the minimum total power required to locate Z targets when the positioning accuracy constraint conditions are met. The specific process is as follows:

[0063] S303-1: Combine tr(C(ψ,N,P,B))≤ε p , obtain the total power objective function of power with respect to bandwidth and aperture P = f(B,N), and then combine Convert the equality constraint part into a penalty function and add it to the total power objective function to obtain the objective function f(P,B,N) = 1 T P+(1 T B - B total ) 2 +(1 T N - N total ) 2 ;

[0064] S303-2: Uniformly allocate the aperture and set the initial value of the aperture N k,opt assigned to the Z targets in the positioning group as N 0 , that is, at this time N k,opt = N 0 ;

[0065] S303-3: Bandwidth optimization: Convert the power P into a function of the bandwidth B. At this time, the objective function is: Use the gradient descent method: where α is a constant representing the learning rate, and solve for the optimal bandwidth allocation B k,opt in the positioning group at the k-th iteration;

[0066] S303-4: Aperture Optimization: Let B = B k,opt , at this time, the power P is a function of the aperture N, and the objective function is: Using the gradient descent method: Solve for the optimal aperture allocation N within the k-th iteration positioning group k,opt ;

[0067] S303-5: Substitute B k,opt , N k,opt into P = f(B, N) to solve for the optimal power allocation P for the k-th iteration k,opt .

[0068] S304: If the minimum total power at this time is less than the total power P of the radar total , it means that the Z targets at this time are the effective positioning group. Otherwise, remove the target with the lowest cost performance from the positioning group in turn until the minimum total power required by the positioning group is less than the total power P of the radar total ;

[0069] S305: Select the targets in the final effective positioning group as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

[0070] In this embodiment, first, the minimum bandwidth required to achieve clutter filtering in the time domain is derived based on the prior information of the targets. Secondly, for the task scenario of the radar facing saturation strikes, a resource allocation strategy that maximizes the radar benefit is proposed, which can balance the contradiction between system performance and the requirements of multi-target positioning tasks. Finally, according to the target benefit and resource consumption, a cost performance function is defined, and the greedy algorithm is used to optimize the target selection and power allocation of the airborne phased array radar, and a resource allocation scheme that maximizes the radar benefit can be obtained.

[0071] Embodiment 2

[0072] Corresponding to Embodiment 1 of the present invention, this embodiment provides an airborne phased array radar resource management system for low-altitude target positioning, including the following modules:

[0073] Minimum clutter-free bandwidth calculation module: used to calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets, specifically including the following units:

[0074] Distance resolution determination unit: used to divide the radar beam into m distance resolution units, so that the distance resolution ΔR satisfies where D q is the distance from the radar to target q; is the distance between the radar and the ground along the beam direction of target q;

[0075] Minimum clutter-free bandwidth acquisition unit: used to calculate according to the formula Calculate the minimum clutter - free bandwidth allocated for the radar - located target q, where c is the speed of light and D q,g is the distance between the target q and the ground along the beam direction of the located target q;

[0076] Establish a resource management model module: It is used to establish an airborne phased - array radar resource management model for low - altitude target location with the maximization of radar revenue as the objective function and the minimum clutter - free bandwidth, target location accuracy, radar aperture, and total power as the constraint conditions. The specific radar resource management model is: where ω = [ω 1 , ω 2 , …, ω q , …, ω Q represents the target revenue vector, where ω q represents the revenue of the radar for locating the q - th target; means maximizing the objective function ω by optimizing the variables u, P, B, N; C(ψ, N, P, B) is the Cramer - Rao lower - bound matrix, ψ = [ψ 1 , ψ 2 , …, ψ q , …, ψ Q is the target position state vector, and its q - th element is ψ q = [x q , y q T , representing the position state of the q - th target, x q and y q respectively represent the positions of the q - th target on the x - axis and y - axis in the two - dimensional plane; ε p represents the predetermined accuracy of target location; N = [N 1 , N 2 , …, N q , …, N Q is the radar aperture vector, and its q - th element is N q , representing the radar aperture allocated for the airborne phased - array radar to locate the q - th target; P = [P 1 , P 2 , …, P q , …, P Q is the power vector, and its q - th element is P q , representing the power transmitted by the phased - array radar to locate the q - th target; B = [B 1 , B 2 , …, B q , …, B Q is the bandwidth vector, and its q - th element is B q , representing the signal bandwidth allocated for the phased - array radar to locate the q - th target; u = [u 1 , u 2 ​,…,u q ,…,u Q is the state vector, and u q indicates whether the q-th target is located: u q When = 1, the power, bandwidth, and aperture allocated for locating target q are all positive; u q When = 0, the power, bandwidth, and aperture allocated for locating target q are all 0; B min,q represents the minimum clutter-free bandwidth of the q-th target; B total is the total bandwidth of the phased array radar; P total represents the total power of the phased array radar; N total is the total number of array elements of the phased array radar.

[0077] The module for obtaining the scheme with maximized benefit: used to define the cost performance function according to the target benefit and resource consumption, optimize the target selection and power allocation of the airborne phased array radar by using the greedy algorithm, and obtain the resource allocation scheme with maximized radar benefit, specifically including the following units:

[0078] The unit for calculating the target cost performance: used to calculate the cost performance of each target by using the formula where ω q represents the benefit of the radar for locating the q-th target, D q is the distance from the radar to target q, D q,g is the distance between target q and the ground in the direction of target q, and sort them from low to high, named the target group;

[0079] The unit for determining the location group: used to select the Z targets with the highest cost performance and add them to the location group, where Z < Q;

[0080] The unit for calculating the minimum total power of the location group: used to optimize the power P, bandwidth B, and aperture N under the constraints of the total bandwidth and total aperture resources, and use the alternating iteration method to calculate the minimum total power required for locating Z targets when meeting the location accuracy constraint conditions;

[0081] The unit for determining the effective location group: used to judge whether the minimum total power required by the location group is less than the total power P of the radar total , if it is less, then define the Z targets at this time as the effective location group, otherwise remove the target with the lowest cost performance from the location group in turn until the minimum total power required by the location group is less than the total power P of the radar total , and take the targets in the final effective location group as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

[0082] In this embodiment, the minimum clutter-free bandwidth is first obtained through the minimum clutter-free bandwidth calculation module. The allocated bandwidth for target positioning is greater than this minimum clutter-free bandwidth to achieve time-domain clutter filtering. Secondly, according to the resource management model establishment module, an airborne phased array radar resource management model for low-altitude target positioning is established, with the maximization of radar benefit as the objective function and the minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as the constraints. Furthermore, a resource allocation strategy for maximizing radar benefit is proposed, which balances the system resources and the task requirements of positioning multiple targets, and ensures high-precision multi-target positioning under the limitation of system resources. Finally, using the maximum benefit acquisition scheme module, the target selection and power allocation of the airborne phased array radar are optimized to obtain a resource allocation scheme for maximizing radar benefit.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for airborne phased array radar resource management for low-altitude target positioning, characterized in that: The following steps are involved: S1: Calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets, specifically: S101: Divide the radar beam into m range resolution units, and the range resolution ΔR of the unit where the target q is located satisfies Where m represents the number of distance resolution units, D q is the distance from the radar to the target q; is the distance between the radar and the ground along the q-beam direction of the positioning target; S102: Using formula Calculate the minimum clutter-free bandwidth allocated for radar positioning target q, c is the speed of light, D q,g is the distance between target q and the ground along the direction of the positioning target q beam; S2: Taking maximizing radar revenue as the objective function and taking minimum clutter-free bandwidth, target positioning accuracy, radar aperture and total power as constraints, a resource management model of airborne phased array radar for low-altitude target positioning is established; S3: Define the cost-effectiveness function according to the target benefit and resource consumption, and use the greedy algorithm to optimize the target selection and power allocation of the airborne phased array radar to obtain the resource allocation plan that maximizes the radar benefit.

2. The airborne phased array radar resource management method for low-altitude target positioning according to claim 1 is characterized in that: In step S2, the airborne phased array radar resource management model for positioning Q low-altitude targets is: where ω=[ω1,ω2,…,ω q ,…,ω Q ] represents the target return vector, where ω q represents the benefit of locating the qth target to the radar; It means that the objective function ω is maximized by optimizing the variables u, P, B, and N; C(ψ,N,P,B) is the Cramer-Rao lower bound matrix, ψ=[ψ1,ψ2,…,ψ q ,…,ψ Q ] is the target position state vector, whose qth element is ψ q =[x q ,y q ] T , represents the position state of the qth target, x q ,y q Respectively represent the position of the qth target on the x-axis and y-axis on the two-dimensional plane; ε p Indicates the predetermined accuracy of target positioning; N = [N1, N2, ..., N q ,…,N Q ] is the radar aperture vector, whose qth element is N q , represents the radar aperture assigned when the airborne phased array radar locates the qth target; P = [P1, P2, ..., P q ,…,P Q ] is a power vector, whose qth element is P q , represents the power emitted by the phased array radar to locate the qth target; B = [B1, B2, …, B q ,…,B Q ] is the bandwidth vector, whose qth element is B q , represents the signal bandwidth allocated when the phased array radar locates the qth target; u=[u1,u2,…,u q ,…,u Q ] is the state vector, u q Indicates whether the qth target is located: u q =1, the power, bandwidth and aperture allocated when locating target q are all positive; u q = 0, the power, bandwidth and aperture allocated when locating target q are all 0; B min,q represents the minimum clutter-free bandwidth of the qth target; B total is the total bandwidth of the phased array radar; P total Represents the total power of the phased array radar; N total is the total number of array elements of phased array radar.

3. The airborne phased array radar resource management method for low-altitude target positioning according to claim 2 is characterized in that: The process of solving the Cramer-Rao lower bound matrix C(ψ,N,P,B) is as follows: according to the time delay positioning and the arrival direction positioning, the Fisher matrix is ​​solved separately and combined, and the combined Fisher matrix is ​​inverted to obtain the Cramer-Rao lower bound matrix C(ψ,N,P,B).

4. The airborne phased array radar resource management method for low-altitude target positioning according to claim 3 is characterized in that: The Fisher matrix solved according to the time delay positioning is: Where P q represents the power emitted by the phased array radar to locate the qth target, B q N represents the signal bandwidth allocated when the phased array radar locates the qth target. q It represents the radar aperture assigned when the airborne phased array radar locates the qth target; in G is the radar gain, ξ q is the radar cross-sectional area of ​​target q, D q is the distance from the radar to the target q, is the variance of zero-mean Gaussian white noise, Where c is the speed of light, x q ,y q Respectively represent the position of the qth target on the x-axis and y-axis on the two-dimensional plane, x P ,y P They represent the position of the radar on the x-axis and y-axis on the two-dimensional plane respectively.

5. The method for airborne phased array radar resource management for low-altitude target positioning according to claim 4, characterized in that: The Fisher matrix solved according to the arrival direction positioning is: In the formula in 6. The airborne phased array radar resource management method for low-altitude target positioning according to claim 4 or 5, characterized in that: The Fisher matrix for joint time delay positioning and arrival direction positioning is J T-D (ψ q )=J T (ψ q )+J D (ψ q ), the inversion of the Fisher matrix is ​​used to obtain the Cramer-Rao lower bound matrix, that is, the Cramer-Rao lower bound matrix 7. The method for airborne phased array radar resource management for low-altitude target positioning according to claim 2, characterized in that: The process of step S3 is: S301: Set the cost performance of target q to where ω q represents the benefit of locating the qth target to the radar, D q is the distance from the radar to the target q, D q,g is the distance between target q and the ground in the direction of target q. The cost performance of Q targets is calculated respectively and sorted from low to high, which is named as target group; S302: Select Z targets with the highest cost-effectiveness and add them to the positioning group. <Q; S303: Under the constraints of total bandwidth and total aperture resources, the power P, bandwidth B and aperture N are optimized, and the minimum total power required for positioning Z targets while satisfying the positioning accuracy constraint is calculated using an alternating iteration method; S304: If the minimum total power at this time is less than the total power P of the radar total , it means that the Z targets at this time are the effective positioning group, otherwise the targets with the lowest cost performance are removed from the positioning group in turn until the minimum total power required by the positioning group is less than the total power P of the radar. total ; S305: taking the targets in the final effective positioning group as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

8. The method for airborne phased array radar resource management for low-altitude target positioning according to claim 7, characterized in that: In step S301, Where k1 is a constant greater than zero.

9. The method for airborne phased array radar resource management for low-altitude target positioning according to claim 7, characterized in that: The specific process of step S303 is: S303-1: Combine tr(C(ψ,N,P,B))≤ε p , obtain the total power objective function P = f(B,N) with respect to bandwidth and aperture, and then combine Convert the equality constraint part into penalty function and add it to the total power objective function to obtain the objective function f(P,B,N)=1 T P+(1 T BB total ) 2 +(1 T NN total ) 2 ; S303-2: Evenly distribute the apertures and set the apertures N allocated to the Z targets in the positioning group k,opt The initial value of N0 is N k,opt =N0; S303-3: Bandwidth optimization: The power P is converted into a function related to the bandwidth B. At this time, the objective function is: Using gradient descent: Where α represents the learning rate, which is a constant. Solve the optimal bandwidth allocation B in the k-th iteration positioning group. k,opt ; S303-4: Aperture optimization: Let B = B k,opt , at this time, the power P is a function of the aperture N, and the objective function is: Using gradient descent: Solve the optimal aperture allocation N within the kth iteration positioning group k,opt ; S303-5: B k,opt 、N k,opt Substitute P = f(B, N) to solve the corresponding k-th iteration optimal power allocation P k,opt .

10. An airborne phased array radar resource management system for low-altitude target positioning, characterized in that: Includes the following modules: Calculation of minimum clutter-free bandwidth module: used to calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets, including the following units: Determine the range resolution unit: used to divide the radar beam into m range resolution units so that the range resolution ΔR satisfies Where D q is the distance from the radar to the target q; is the distance between the radar and the ground along the q-beam direction of the positioning target; Get the minimum clutter-free bandwidth unit: Used to calculate the minimum clutter-free bandwidth unit according to the formula Calculate the minimum clutter-free bandwidth allocated to the radar to locate the target q, where c is the speed of light, D q,g is the distance between target q and the ground along the direction of the positioning target q beam; Establish resource management model module: It is used to establish the resource management model of airborne phased array radar for low-altitude target positioning, taking maximizing radar revenue as the objective function and taking minimum clutter-free bandwidth, target positioning accuracy, radar aperture and total power as constraints; Obtaining the maximum benefit plan module: It is used to define the cost-effectiveness function according to the target benefit and resource consumption, and use the greedy algorithm to optimize the target selection and power allocation of the airborne phased array radar to obtain the resource allocation plan that maximizes the radar benefit.

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