Airborne phased array radar resource management method and system for low-altitude target positioning

Abstract

The present invention provides a resource management method for airborne phased array radars for low-altitude target positioning, belonging to the field of radar. The method comprises the following steps: S1: calculating the minimum clutter-free bandwidth based on prior information about the low-altitude target; S2: establishing an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar revenue as the objective function and minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as constraints; S3: defining a cost-performance function based on target revenue and resource consumption, optimizing target selection and power allocation for the airborne phased array radar using a greedy algorithm, and obtaining a resource allocation solution that maximizes radar revenue. The present invention calculates and allocates the minimum clutter-free bandwidth so that ground clutter is filtered out in the time domain when positioning the target; and proposes a resource allocation strategy that maximizes radar revenue, balancing the contradiction between resource limitations and the requirements of multiple target positioning tasks, optimizing radar target selection and power allocation, and achieving maximum radar revenue.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a resource management method and system for airborne phased array radars 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 resource allocation optimization at the macro level, improving resource utilization and radar performance by rationally allocating resources such as power, bandwidth, waveform, radar nodes, and dwell time. For example, patent publication number CN108333583A discloses a resource allocation method based on dual-target optimization of phased array radar search and tracking. It obtains Pareto subsets by solving the convex minimax optimization problem in parallel, achieving efficient resource allocation and simplifying the resource allocation process.

[0003] However, there are still many problems that need 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. The positioning of low-altitude targets faces many unique problems. The interference of clutter is more serious. Their signals are often covered by ground reflection or scattered clutter, resulting in a significant decrease in the signal-to-noise ratio. In addition, due to their low flying altitude, low-altitude targets have greater motion uncertainty, which exacerbates the complexity of positioning. When dealing with low-altitude target positioning, existing radar resource management strategies usually find it difficult to balance resource allocation and positioning accuracy requirements under the constraints of limited hardware resources. This makes low-altitude target positioning 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] To solve the above technical problems, the present invention provides the following technical solution: a method for airborne phased array radar resource management 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 distance resolution units, D q is the distance from the radar to the target q; is the distance between the radar and the ground in the direction of the beam locating the target q;

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

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

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

[0011] The present invention divides the radar beam into multiple range resolution units. By adjusting the size of the range resolution units so that they only cover the target, the ground reflection signal can be filtered out as much as possible, so that the echo is mainly composed of the target signal. The maximum range resolution unit is determined, and then the minimum clutter-free bandwidth is determined. At this time, ensuring that the bandwidth allocated to the radar when locating the target is greater than the minimum clutter-free bandwidth can filter out ground clutter, which can significantly reduce the interference of ground clutter on target positioning performance.

[0012] Preferably, 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 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=[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 two-dimensional plane on the x-axis and y-axis; ε pIndicates 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 the 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 the target q are all positive; u q = 0, the power, bandwidth and aperture allocated when locating the 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 the phased array radar.

[0013] Preferably, 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).

[0014] Preferably, the Fisher matrix solved according to time delay positioning is Where P q represents the power emitted by the phased array radar when locating 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, x q 、yq Respectively represent the position of the qth target on the x-axis and y-axis on the two-dimensional plane, x P 、y P Respectively represent the position of the radar on the x-axis and y-axis on the two-dimensional plane.

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

[0016] Preferably, 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 inverse of the Fisher matrix is used to obtain the Cramer-Rao lower bound matrix, that is, the Cramer-Rao lower bound matrix

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

[0018] S301: Set the price / performance ratio of target q to where ω q Denotes 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 The distance between target q and the ground in the direction of target q is calculated. The cost performance of Q targets is calculated and sorted from low to high, and named as target group;

[0019] S302: Select the Z targets with the best cost-effectiveness and add them to the positioning group. <Q;

[0020] S303: Under the constraints of total bandwidth and total aperture resources, optimize the power P, bandwidth B, and aperture N, and use an alternating iterative method to calculate the minimum total power required to locate Z targets while meeting the positioning accuracy constraints;

[0021] 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 ;

[0022] S305: The targets in the final valid positioning group are taken 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 airborne phased array radar under the constraints of total bandwidth and total aperture resources, balancing the contradiction between system resources and multi-target positioning requirements. While ensuring the positioning accuracy of multiple targets, the system resources are consumed as little as possible to maximize the radar benefit.

[0024] Preferably, in step S301, Where k1 is a constant greater than zero.

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

[0026] 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 into the total power objective function to obtain objective function f(P,B,N)=1 T P+(1 T BB total ) 2 +(1 T NN total ) 2 ;

[0027] S303-2: Evenly distribute the apertures and set the aperture N allocated to the Z targets in the positioning group k,opt The initial value is N0, that is, N k,opt =N0;

[0028] S303-3: Bandwidth optimization: Convert the power P into a function related to the bandwidth B. The objective function is: Using gradient descent: Where α is a constant, representing the learning rate, and the optimal bandwidth allocation B in the k-th iteration positioning group is solved. k,opt ;

[0029] S303-4: Aperture Optimization: Set 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 ;

[0030] 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 .

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

[0032] Minimum clutter-free bandwidth calculation module: used to calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets. It specifically includes the following units:

[0033] Determine the range resolution unit: used to divide the radar beam into m range resolution units so that the range resolution ΔR satisfies Among them D q is the distance between the radar and the target q; is the distance between the radar and the ground along the target q-beam direction;

[0034] Get the minimum noise-free bandwidth unit: Used to calculate the minimum noise-free bandwidth unit according to the formula Calculate the minimum clutter-free bandwidth allocated to the radar positioning 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;

[0035] Establish a resource management model module: This module is used to establish an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar revenue as the objective function and minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as constraints.

[0036] Obtaining the maximization benefit plan module: It is used to define the cost-performance function based on 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.

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

[0038] (1) The present invention divides the radar beam into multiple range resolution units and adjusts their sizes so that they can only cover the target. At this time, the ground reflection signal can be filtered out as much as possible, and the echo is mainly composed of the target signal, which improves the echo signal-to-noise ratio. After determining the maximum range resolution of the radar when locating a certain target, the minimum clutter-free bandwidth at this time can be calculated to ensure that the bandwidth allocated to locating this target is greater than the minimum clutter-free bandwidth. This can effectively filter out clutter, greatly reduce the interference of ground clutter on target positioning performance, and make target positioning more accurate;

[0039] (2) Taking maximizing radar benefit as the objective function and taking target positioning accuracy, system hardware resources and minimum clutter-free bandwidth as constraints, an airborne phased array radar resource management model is proposed. Under resource constraints, a cost-performance function defined by target benefit and resource consumption is proposed. When faced with multiple positioning target task requirements, target selection is optimized based on cost-performance. Under resource constraints, power allocation is further optimized, balancing the contradiction between system resources and multiple target positioning requirements. This can not only achieve preferential target positioning and ensure high-precision positioning of multiple targets, but also achieve reasonable allocation of radar resources, minimize the consumption of system resources, and obtain the maximum radar benefit. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of Example 1 of the present invention;

[0041] Figure 2 This is a diagram of the airborne phased array radar resource management scenario for low-altitude target positioning in Example 1 of the present invention;

[0042] Figure 3 This is a diagram illustrating the beam and range resolution of an airborne phased array radar in Example 1 of the present invention. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, 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 only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0044] Example 1

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

[0046] Step 1: Based on the prior information of the low-altitude target, calculate the minimum clutter-free bandwidth, specifically:

[0047] like Figure 2 As shown, it is assumed that the airborne phased array radar is located at (x P ,y P ), Q low-altitude targets are located at (x q ,y q ),q=1,2,…,Q.

[0048] Combine Figure 3Airborne phased array radars are often subject to severe clutter interference when locating these targets. For intuitive analysis, the radar beam is simplified to a straight line. The beam consists of several range resolution units. If the size of the range resolution unit is appropriately reduced so that it only covers the target, the ground reflection signal can be filtered out as much as possible. At this time, the echo is mainly composed of the target signal, which greatly reduces the interference of ground clutter on target positioning performance. Therefore, it is proposed that the range resolution needs to meet the following requirements: Where m represents the number of range resolution units; ΔR represents the range resolution of the radar; 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.

[0049] Will Variant Therefore, the distance resolution ΔR should satisfy That is, ΔR≤D q,g , D q,g is the distance between target q and the ground along the target q beam direction, and because c is the speed of light, B q represents the signal bandwidth allocated by the phased array radar to locate the target q, then Get the minimum clutter-free bandwidth When locating target q, the allocated bandwidth is larger than the minimum clutter-free bandwidth to filter out ground clutter.

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

[0051] When there are too many targets in the radar monitoring airspace, the radar cannot meet the requirements for positioning all targets. In this case, target selection is necessary. This embodiment uses maximizing radar revenue as the objective function and target positioning accuracy, system hardware resources, and minimum clutter-free bandwidth as constraints to establish an airborne phased array radar resource management model for low-altitude target positioning: 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 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 = [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, xq 、y q Respectively represent the position of the qth target on the two-dimensional plane on the x-axis and y-axis; 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 the 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 the target q are all positive; u q = 0, the power, bandwidth and aperture allocated when locating the 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 the phased array radar.

[0052] Where C(ψ,N,P,B) is the Cramer-Rao Lower Bound (CRLB), which is used to measure the positioning accuracy of the positioning target. It can be obtained by inverting the Fisher Information Matrix (FIM). Based on the Time of Arrival (TOA) positioning, the FIM is: where ψ q =[x q ,y q ] T , expressed as the position state of the qth target, τ q Indicates time delay.

[0053] Therefore, the Jacobian matrix can be expressed as: Use α q and β q represents 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 position of the qth target on the x-axis and y-axis on the two-dimensional plane, x P 、y P Represent the position of the radar on the x-axis and y-axis on the two-dimensional plane, respectively. Then we get: in Where, G is the radar gain, ξ q is the radar cross section (RCS) of the qth target, is the variance of zero-mean Gaussian white noise.

[0054] Similarly, when using Direction of Arrival (DOA) positioning, the FIM is in Where, and

[0055] The FIM of combined TOA and DOA positioning is obtained as follows: T-D (ψ q )=J T (ψ q )+J D (ψ q ), so the CRLB matrix is:

[0056] Step 3: Define a cost-performance function based on target revenue and resource consumption, and use a greedy algorithm to obtain the maximum radar revenue. Specifically:

[0057] To select targets with the highest radar system benefit from a large number of targets, this embodiment uses cost-performance ratio to measure the priority of target positioning. Cost-performance ratio can be expressed as the ratio of the benefit of positioning the target to the expected cost. The benefit of positioning the target is: Where k1 is a constant greater than zero, D q is the distance between the radar and the target q.

[0058] The above formula shows that the benefit 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, a higher range resolution is required to distinguish the target from the ground, which means that a larger bandwidth is required at this time; on the other hand, when the target is farther away from the radar, more resources are required to achieve positioning accuracy. Therefore, considering the above two factors, the cost-effectiveness of the target is expressed as Based on this formula, targets with high cost-performance rankings are prioritized to maximize radar benefits.

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

[0060] S301: Utilize formula Calculate the cost-effectiveness of each of the Q targets and sort them from low to high, naming them as target groups;

[0061] S302: Select the Z targets with the best cost-effectiveness and add them to the positioning group. <Q;

[0062] S303: Under the constraints of total bandwidth and total aperture resources, optimize the power P, bandwidth B, and aperture N, and use an alternating iterative method to calculate the minimum total power required to locate Z targets while meeting the positioning accuracy constraints. The specific process is as follows:

[0063] 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 into the total power objective function to obtain objective function f(P,B,N)=1 T P+(1 T BB total ) 2 +(1 T NN total ) 2 ;

[0064] S303-2: Evenly distribute the apertures and set the aperture N allocated to the Z targets in the positioning group k,opt The initial value is N0, that is, N k,opt =N0;

[0065] S303-3: Bandwidth optimization: Convert the power P into a function related to the bandwidth B. The objective function is: Using gradient descent: Where α is a constant, representing the learning rate, and the optimal bandwidth allocation B in the k-th iteration positioning group is solved. k,opt ;

[0066] S303-4: Aperture Optimization: Set 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 ;

[0067] 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 .

[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, 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 ;

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

[0070] This embodiment first derives the minimum bandwidth required to achieve time-domain clutter filtering based on prior target information. Secondly, for the radar's mission scenario of saturation strike, a resource allocation strategy that maximizes radar benefits is proposed, which can balance the contradiction between system performance and the requirements of multi-target positioning missions. Finally, a cost-effectiveness function is defined based on target benefits and resource consumption, and a greedy algorithm is used to optimize the target selection and power allocation of the airborne phased array radar, thereby obtaining a resource allocation solution that maximizes radar benefits.

[0071] Example 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. It specifically includes the following units:

[0074] Determine the range resolution unit: used to divide the radar beam into m range resolution units so that the range resolution ΔR satisfies Among them D q is the distance between the radar and the target q; is the distance between the radar and the ground along the target q-beam direction;

[0075] Get the minimum noise-free bandwidth unit: Used to calculate the minimum noise-free bandwidth unit according to the formula Calculate the minimum clutter-free bandwidth allocated to the radar positioning 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;

[0076] Establish a resource management model module: This module is used to establish an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar revenue as the objective function and minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as constraints. The specific radar resource management model is as follows: 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 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 = [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 two-dimensional plane on the x-axis and y-axis; 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 the 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 the target q are all positive; u q = 0, the power, bandwidth and aperture allocated when locating the 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 totalis the total number of array elements of the phased array radar.

[0077] Obtaining the Maximized Benefit Plan Module: This module is used to define a cost-performance function based on target benefits and resource consumption, and optimize the target selection and power allocation of the airborne phased array radar using a greedy algorithm to obtain a resource allocation plan that maximizes radar benefits. It specifically includes the following units:

[0078] Calculate target price / performance ratio unit: used to use the formula Calculate the cost-effectiveness of each target, where ω q Denotes 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 It is the distance between target q and the ground in the direction of target q, and is sorted from low to high and named as target group;

[0079] Determine the positioning group unit: used to select the Z targets with the best cost-effectiveness and add them to the positioning group. <Q;

[0080] Calculate the minimum total power unit of the positioning group: It is used to optimize the power P, bandwidth B and aperture N under the total bandwidth and total aperture resource constraints, and use the alternating iterative method to calculate the minimum total power required to locate Z targets while meeting the positioning accuracy constraints;

[0081] Determine the effective positioning group unit: used to determine whether the minimum total power required by the positioning group is less than the total power P of the radar total If it is less than, the Z targets at this time are defined as 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 , the targets in the final effective positioning group are taken as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

[0082] This embodiment first obtains the minimum clutter-free bandwidth through the minimum clutter-free bandwidth calculation module. When locating a target, the bandwidth allocated is greater than this minimum clutter-free bandwidth to achieve time-domain ground clutter filtering. Secondly, the resource management model establishment module establishes an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar benefit as the objective function and minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as constraints. Furthermore, a resource allocation strategy that maximizes radar benefit is proposed, balancing system resources and the task requirements of locating multiple targets. High-precision multi-target positioning is ensured within the constraints of system resources. Finally, the maximum benefit solution acquisition module optimizes target selection and power allocation for the airborne phased array radar to obtain a resource allocation solution that maximizes radar benefit.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for managing airborne phased array radar resources 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 to the 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: Establish an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar revenue as the objective function and minimum clutter-free bandwidth, target positioning accuracy, radar aperture, and total power as constraints. S3: Define a cost-effectiveness function based on target benefit and resource consumption, and use a greedy algorithm to optimize target selection and power allocation of airborne phased array radar to obtain a resource allocation solution that maximizes radar benefit.

2. The airborne phased array radar resource management method for low-altitude target positioning according to claim 1, 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 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=[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 two-dimensional plane on the x-axis and y-axis; 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 the 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 the target q are all positive; u q = 0, the power, bandwidth and aperture allocated when locating the 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 the phased array radar.

3. The airborne phased array radar resource management method for low-altitude target positioning according to claim 2, 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, characterized in that: The Fisher matrix solved according to time delay positioning is Where P q represents the power emitted by the phased array radar when locating 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 Respectively represent the position of the radar on the x-axis and y-axis on the two-dimensional plane.

5. The airborne phased array radar resource management method 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 inverse of the Fisher matrix is used to obtain the Cramer-Rao lower bound matrix, that is, the Cramer-Rao lower bound matrix 7. The airborne phased array radar resource management method for low-altitude target positioning according to claim 2, characterized in that: The process of step S3 is: S301: Set the price / performance ratio of target q to where ω q Denotes 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 The distance between target q and the ground in the direction of target q is calculated. The cost performance of Q targets is calculated and sorted from low to high, and named as target group; S302: Select the Z targets with the best cost-effectiveness and add them to the positioning group. <Q; S303: Under the constraints of total bandwidth and total aperture resources, optimize the power P, bandwidth B, and aperture N, and use an alternating iterative method to calculate the minimum total power required to locate Z targets while meeting the positioning accuracy constraints; 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: The targets in the final valid positioning group are taken as the optimal combination, and the sum of the benefits is the maximum benefit obtained by the airborne phased array radar.

8. The airborne phased array radar resource management method 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 airborne phased array radar resource management method 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 into the total power objective function to obtain 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 aperture N allocated to the Z targets in the positioning group k,opt The initial value is N0, that is, N k,opt =N0; S303-3: Bandwidth optimization: Convert the power P into a function related to the bandwidth B. 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: Set 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: Minimum clutter-free bandwidth calculation module: used to calculate the minimum clutter-free bandwidth based on the prior information of low-altitude targets. It specifically includes 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 Among them 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 noise-free bandwidth unit: Used to calculate the minimum noise-free bandwidth unit according to the formula Calculate the minimum clutter-free bandwidth allocated to the radar positioning 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 a resource management model module: This module is used to establish an airborne phased array radar resource management model for low-altitude target positioning, with maximizing radar revenue as the objective function and 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 based on 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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