A distributed full-coherent radar space synthesis gain distribution simulation modeling method

Abstract

The application relates to a distributed full-phase radar space synthesis gain distribution simulation modeling method, and belongs to the field of radar signal processing. The method comprises the following steps: constructing a distributed full-phase radar model, calculating the time delay difference difference value and the phase difference difference value of each transmitting radar and a reference radar, so that the phase parameters at the target position are obtained; calculating the vector angle and the attenuation coefficient at the space point of each radar; calculating the signal at the space point of each transmitting radar; and calculating the transmission space synthesis gain distribution data. The distributed full-phase radar space synthesis gain distribution simulation modeling method provided by the application can obtain the space synthesis gain distribution of the distributed full-phase radar in any array form at low cost, and effectively makes up for the blank in the technical field. Compared with the experimental method through the actual machine equipment, the method is simulated through the computer, the cost of obtaining the space synthesis gain distribution data of the distributed full-phase radar is significantly reduced, and data support is provided for array optimization technology research.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radar signal processing, in particular to a simulation modeling method for spatial synthetic gain distribution of distributed full-phase radar. BACKGROUND

[0002] In the application scenarios of long-range search, tracking, surveillance and target identification, large-aperture, high-power large-scale phased array radars play an increasingly important role. However, with the increasing requirements for power and accuracy, the development of large-scale phased array radars is restricted by various negative factors such as rapid increase in construction cost and sharp decline in mobility, and distributed full-phase radars emerge as the times require. The electromagnetic signals transmitted by N transmitting radars of the distributed full-phase radar are superimposed in space after accurate synchronization and compensation, and theoretically, the N 2 spatial synthetic gain can be obtained. However, in actual application, there are measurement errors in phase correlation parameter estimation and target positioning, which cannot guarantee that the target point is located in the range with the maximum synthetic gain. Therefore, how to maximize the range of signal superposition under the condition of limited resources is an important research problem. The range of phase correlation superposition of the distributed full-phase radar in the target space is mainly affected by radar performance parameters, synchronization accuracy and array geometry, among which the array geometry parameters have the most significant impact. The present application proposes a new simulation modeling method for spatial synthetic gain distribution of distributed full-phase radar, which provides prior data support for array optimization research of this type of radar.

[0003] At present, domestic and international experts and scholars have conducted in-depth research on the problem of radar array optimization. The China Electronics Scientific Research Institute proposed a research and analysis method for the constraint of signal correlation on the form of distributed MIMO radar. According to the constraint condition of signal correlation, the corresponding relationship between the maximum distance of each node and each working frequency of the space-air distributed radar is given. From the perspective of cost-effectiveness, the relationship between the effect of increasing the number of nodes on improving the equivalent synthetic gain is analyzed. The Thirty-Eighth Institute of China Electronics Technology Group conducted research on the array and usage of large-scale random arrays, and proposed a design and analysis method for random array and detection performance optimization. Abroad, the Lincoln Laboratory of the United States has made a lot of research on distributed full-phase radars and achieved certain results. The Lehigh University of the United States proposed a best linear unbiased estimator for the target positioning problem in the wide-area distributed application scenario of MIMO radar, which helps to analyze the relationship between sensor position, target position and positioning accuracy. At present, there are few simulation modeling researches on the spatial synthetic gain distribution of distributed full-phase radars.

[0004] In actual engineering applications, the simulation analysis and real machine experiment combination method is used for single radar to analyze and verify the energy distribution of radar transmitting signals. Due to the multiple units of the distributed full-phase radar, it will lead to the problems of great difficulty, high time cost and equipment cost in real experiment. SUMMARY

[0005] The technical problem solved by the present application is:

[0006] In order to avoid the shortcomings of the prior art, the present application provides a distributed full-phase radar spatial synthesis gain distribution simulation modeling method, which provides prior data support for distributed full-phase radar array optimization.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0008] A distributed full-phase radar spatial synthesis gain distribution simulation modeling method, characterized in that it comprises:

[0009] A distributed full-phase radar model is constructed, and the distributed full-phase radar model comprises a plurality of transmitting radars in a full-phase working mode;

[0010] The time delay and phase difference of each radar to the target position are calculated based on the coordinate values of each transmitting radar and the target, and the time delay difference and phase difference difference of each transmitting radar and the reference radar are calculated based on the time delay and phase difference of each transmitting radar and the reference radar, that is, the phase parameters at the target position;

[0011] The first included angle of each radar to the spatial point vector and the coordinate origin to the spatial point vector is calculated based on the cosine theorem, the second included angle of the spatial point to the transmitting radar position vector and the target point to the transmitting radar position vector is calculated based on the cosine theorem, and the attenuation coefficient is calculated based on the second included angle and the spatial point vector of each radar;

[0012] The time delay and phase difference of each radar to the spatial point are calculated based on the coordinate values of each transmitting radar and the spatial point, and the signal of each transmitting radar to the spatial point is calculated based on the phase parameters at the target position, the time delay and phase difference of each radar to the spatial point, and the attenuation coefficient;

[0013] The superposition signal of the distributed full-phase radar at the spatial point is calculated based on the signal of each transmitting radar to the spatial point and the first included angle, and the spatial synthesis gain distribution data of each radar is obtained based on the ratio of the superposition signal power to the radar signal power.

[0014] The further technical scheme of the present application is that the time delay and phase difference of each radar to the target position are calculated based on the coordinate values of each transmitting radar and the target, and the following formula is used:

[0015]

[0016] φ m = 2πf0τ m

[0017] Wherein, (x m , y m , z m ) is the coordinate of the mth radar position in the Cartesian coordinate system, c is the speed of light, (R t , alpha t , beta t ) is the space spherical coordinate of the scattering point target, f0 is the working frequency, tau m is the time delay of each radar to the target position, phi m is the phase difference of each radar to the target position.

[0018] The further technical scheme of the application: the time delay difference value and the phase difference value of each transmitting radar and the reference radar are calculated based on the time delay and the phase difference of each transmitting radar and the reference radar respectively, and the following formula is used:

[0019] Delta tau m = tau m -tau1

[0020] Delta phi m = 2pi f0 Delta tau m

[0021] Wherein, tau1 is the time delay of the reference radar.

[0022] The further technical scheme of the application: the first included angle of the space point vector reached by the radar and the space point vector from the coordinate origin is calculated based on the cosine theorem, and the following formula is used:

[0023]

[0024] Wherein, is the space point vector reached by the radar, is the space point vector from the coordinate origin, (r, alpha, beta) is the spherical coordinate of the space point, theta m,P is the first included angle.

[0025] The further technical scheme of the application: the second included angle of the space point to the transmitting radar position vector and the target point to the transmitting radar position vector is calculated based on the cosine theorem, and the following formula is used:

[0026]

[0027] Wherein, is the target point to the transmitting radar position vector, theta m,P,Q is the second included angle.

[0028] The application further has a technical scheme that the attenuation coefficient is calculated based on the second included angle and the spatial point vector of each radar, and the following formula is used:

[0029]

[0030] The application further has a technical scheme that the time delay and the phase difference of each radar reaching a spatial point are calculated based on the coordinate values of each radar and the spatial point, and the following formula is used:

[0031]

[0032] φ m,P = 2πf0τ m,P

[0033] wherein τ m,P is the time delay of the radar reaching the spatial point, and φ m,P is the phase difference of the radar reaching the spatial point.

[0034] The application further has a technical scheme that the signal of each radar reaching a spatial point is calculated based on the coherent parameters at the target position, the time delay and the phase difference of each radar reaching the spatial point, and the attenuation coefficient, and the following formula is used:

[0035]

[0036] The application further has a technical scheme that the superposition signal of the distributed full-coherent radar at a spatial point is calculated based on the signal of each radar reaching the spatial point and the first included angle, and the following formula is used:

[0037]

[0038] The application further has a technical scheme that the ratio of the superposition signal power to the radar signal power is used, and the following formula is used:

[0039]

[0040] wherein s1(t, r, α, β) is the transmitting signal of the T1 radar.

[0041] The application has the following beneficial effects:

[0042] The distributed full-coherent radar spatial synthesis gain distribution simulation modeling method provided by the application realizes the energy distribution and the transmitting gain distribution simulation of the transmitting signal of the distributed full-coherent radar in space for any number of unit radars and any array distribution form on a computer, effectively saves the cost of physical experiments, provides prior data support for the array optimization of the distributed full-coherent radar, and makes up for the technical research gap.

[0043] 1.The distributed full coherent radar spatial synthesis gain distribution simulation modeling method provided by the present application can obtain the spatial synthesis gain distribution of a distributed full coherent radar with any array form at low cost, effectively filling the gap in this technical field. Compared with the experimental method through real equipment, the method of the present application is simulated by a computer, which significantly reduces the cost of obtaining the spatial synthesis gain distribution data of the distributed full coherent radar, and provides data support for array optimization technology research.

[0044] 2.Compared with direct testing of real objects, the distributed full coherent radar spatial synthesis gain distribution simulation modeling method provided by the present application can more flexibly obtain the spatial synthesis gain distribution of any array form, any radar parameter, and any airspace, which is not limited by experimental sites, equipment construction costs, etc., can effectively shorten the experimental period, significantly improve the experimental efficiency, and quickly and efficiently obtain the spatial synthesis gain distribution data. BRIEF DESCRIPTION OF DRAWINGS

[0045] The accompanying drawings are included to provide a further understanding of the present application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the principles of the present application. In the drawings:

[0046] Figure 1 Flow chart of the embodiment of the present application;

[0047] Figure 2 Transmitting radar and spatial point distribution diagram of the present application;

[0048] Figure 3 Model airspace range schematic diagram of the present application;

[0049] Figure 4 Model Matlab simulation result of the present application - spatial synthesis gain distribution profile diagram. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0051] The present application provides a distributed full coherent radar spatial synthesis gain distribution simulation modeling method, comprising the following steps:

[0052] S01: input model parameters. Define radar parameters, target position coordinates, and position coordinates of each transmitting radar of the distributed full-phase radar. Set the signal sampling rate and time window width according to the radar parameters; design the corresponding spatial resolution according to the requirement of obtaining spatial synthesis gain distribution data. According to the actual scene requirement, set the synchronization error parameter between radars, and the default value is 0.

[0053] S02: calculate the phase parameters. Calculate the time delay and phase difference of each radar to the target position. Select a certain radar in the transmitting radar or set a virtual radar as the reference radar, and calculate the time delay difference and phase difference difference between each transmitting radar and the reference radar, so as to obtain the phase parameters at the target position.

[0054] S03: calculate the vector angle and attenuation coefficient of each radar to the spatial point. Use the cosine theorem to calculate the angle between the vector of each radar to the spatial point and the vector from the coordinate origin to the spatial point. Use the cosine theorem to calculate the angle between the vector from the spatial point to the transmitting radar position and the vector from the target point to the transmitting radar position, query the corresponding directional diagram gain of the angle deviation from the radar directional diagram, divide by the square of the distance from the radar to the spatial point, and obtain the attenuation coefficient of the radar to the corresponding spatial point.

[0055] S04: calculate the signal of each transmitting radar to the spatial point. Set an initial signal, calculate the time delay difference and phase difference of each transmitting radar to the spatial point, introduce the time delay difference and phase difference to the initial signal, and then perform phase parameter compensation to obtain the signal of each transmitting radar to the spatial point.

[0056] S05: calculate the transmitting spatial synthesis gain distribution data. Multiply the signal of each radar to the spatial point by the attenuation coefficient, then multiply by the cosine value of the vector angle to the spatial point, and finally add all the signals to obtain the superimposed signal at the spatial point. Calculate the average power of the superimposed signal and the average power of the signal of a single radar at the spatial point, calculate the ratio of the two, which is the transmitting phase gain of the distributed full-phase radar at the spatial point with the target point as the reference. Loop the above process to traverse all spatial points and calculate the corresponding transmitting phase gain to obtain the spatial synthesis gain distribution data of the distributed full-phase radar in this array form.

[0057] Embodiment 1:

[0058] The embodiment of the application provides a distributed full-phase radar spatial synthesis gain distribution simulation modeling method, which comprises the following steps:

[0059] S01: set the model parameters. Define the number of transmitting radars of the distributed full-phase radar as M, and the transmitting radars are denoted as (T1, T2, …, T M ), the coordinates of the mth transmitting radar in the Cartesian coordinate system are (x m , y m , zm ). Each transmitting radar has the same transmitting parameters, transmitting power p, operating frequency f0; the transmitting directional pattern gain is set as μ(θ), where θ represents the included angle between the direction of the transmitting radar to the spatial point and the center of the beam; under the full phase mode, the transmitting signal of each transmitting radar is s(t), and the light speed is c. There is an isotropic scattering point target Q in the space, whose spherical coordinates are (R t ,α t ,β t ); any point P in the space is denoted as (r,α,β). The distribution diagram of the transmitting radar and the spatial point is shown in Figure 2 .

[0060] S02: Calculate the phase parameters. The transmitting time delay phase parameters of each transmitting radar are denoted as (Δτ1,Δτ2,…,Δτ M ); the transmitting phase phase parameters are denoted as (Δφ1,Δφ2,…,Δφ M ). Here, it is assumed that T1 is the reference radar, then Δτ1=0s and Δφ1=0. τ m represents the propagation time delay of the signal from T m to the target point Q. Then the transmitting phase parameters of each transmitting radar can be calculated in the following way:

[0061]

[0062] φ m =2πf0τ m

[0063] Δτ m =τ m -τ1

[0064] Δφ m =2πf0Δτ m

[0065] wherein τ1 is the time delay of the reference radar.

[0066] S03: Calculate the vector included angle and the attenuation coefficient of each radar to the spatial point. The included angle of each radar to the spatial point is shown in Figure 2 , where θ m,P represents the included angle between the coordinate origin and T m to the spatial point P, and the calculation method is as follows:

[0067]

[0068] The attenuation coefficient of the radar to the space is related to the target distance and the beam directional pattern gain. Here, it is assumed that the center of each transmitting radar points to the target point Q, then the included angle of the spatial point P to the center of the beam can be represented as θ m,P,Q , so as to obtain the directional pattern gain μ(θ m,P,Q) ; μ(θ m,P,Q ) divided by the square of the distance from the radar to the spatial point, i.e. the attenuation coefficient ξ m,P , is calculated as follows.

[0069]

[0070] S04: Calculate the signal at each transmitting radar spatial point. According to the calculated parameters above, the signal s m (t, r, a, b) transmitted by each radar to the spatial point P can be obtained, where t is the time, r is the distance, a is the azimuth angle, b is the elevation angle, τ m,P is the propagation time delay of the transmitting radar T m to the spatial point P, and φ m,P is the phase difference introduced during propagation, which is calculated as follows.

[0071]

[0072] φ m,P = 2pft m,P

[0073]

[0074] where p m is the power of the radar transmitted signal.

[0075] S05: Calculate the transmitting spatial synthesis gain distribution data. First, calculate the superimposed signal of the distributed full-phase radar at the spatial point P, which is calculated as follows.

[0076]

[0077] Then, calculate the transmitting phase gain of the distributed full-phase radar at the spatial point P. By calculating the ratio of the superimposed signal power to the single radar signal power, the transmitting phase gain G P (r, a, b) can be quantified, where T1 transmitted signal is taken as the reference, and the calculation method is as follows.

[0078]

[0079] By traversing the transmitting phase gain of the spatial points near the target point Q, the spatial synthesis gain distribution data under the arrangement form of (T1, T2, …, T M ) can be calculated. Define the spatial azimuth angle range as Ψ, the elevation angle range as Y, and the distance range as d. The spatial range diagram is shown in Figure 3 , and the blue part is the spatial range. Define the distance sampling rate as Ad, the spatial azimuth sampling rate as Da, and the spatial elevation sampling rate as Db. The coordinates (r, a, b) of the spatial point P can be represented as follows. The spatial synthesis gain profile simulation results of several typical arrangement forms are shown in Figure 4 .

[0080] r = r t + nAd - d / 2

[0081] a = a t + IAA - a / 2

[0082] b = b t + kAb - b / 2

[0083]

[0084] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements shall be encompassed within the protection scope of the present application.

Claims

1. A distributed full-coherent radar spatial synthetic gain distribution simulation modeling method, characterized in that, The application relates to a method for calculating the spatial synthetic gain distribution of a distributed full-phase radar. The method comprises the following steps: constructing a distributed full-phase radar model, wherein the distributed full-phase radar model comprises a plurality of transmitting radars in a full-phase working mode; calculating the time delay and phase difference of each radar to the target position based on the coordinate values of each transmitting radar and the target; determining a reference radar, and calculating the time delay difference and phase difference difference of each transmitting radar and the reference radar based on the time delay and phase difference of each transmitting radar and the reference radar, i.e. the full-phase parameters at the target position; calculating the first included angle between the spatial point vector reached by each radar and the spatial point vector from the coordinate origin based on the cosine theorem; calculating the second included angle between the spatial point vector from the transmitting radar position and the spatial point vector from the target position based on the cosine theorem; and calculating the attenuation coefficient based on the second included angle and the spatial point vector reached by each radar; calculating the time delay and phase difference of each radar to the spatial point based on the coordinate values of each transmitting radar and the spatial point; and calculating the signal of each transmitting radar at the spatial point based on the full-phase parameters at the target position, the time delay and phase difference of each radar to the spatial point, and the attenuation coefficient; 2. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 1, characterized in that, calculating the superposition signal of the distributed full-phase radar at the spatial point based on the signal of each transmitting radar at the spatial point and the first included angle; and obtaining the spatial synthetic gain distribution data of each radar based on the ratio of the superposition signal power to the signal power of each radar. wherein, is the number of transmitting radar positions, m is the coordinate of the i-th transmitting radar position in the Cartesian coordinate system, c is the speed of light, is the spatial spherical coordinate of the scattering point target, is the operating frequency, is the time delay of each radar to the target position, is the phase difference of each radar to the target position.

3. The method according to claim 2, wherein, The time delay and phase difference of each radar to the target position are calculated based on the coordinate values of each transmitting radar and the target, and the following formula is used: wherein, is the time delay of the reference radar.

4. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 3, characterized in that, The time delay difference and phase difference difference of each transmitting radar and the reference radar are calculated based on the time delay and phase difference of each transmitting radar and the reference radar, and the following formula is used: wherein, is the vector of the spatial point of arrival, is the vector of the spatial point of origin, is the spherical coordinates of the arbitrary point in space, is the first angle.

5. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 4, characterized in that, The first included angle between the spatial point vector reached by each radar and the spatial point vector from the coordinate origin is calculated based on the cosine theorem, and the following formula is used: wherein, is a vector from the target point to the transmitting radar position, is a second included angle.

6. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 5, characterized in that, The second included angle between the spatial point vector from the transmitting radar position and the spatial point vector from the target position is calculated based on the cosine theorem, and the following formula is used: 。 7. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 6, characterized in that, The attenuation coefficient is calculated based on the second included angle and the spatial point vector reached by each radar, and the following formula is used: wherein, is the time delay of the lightning to reach the spatial point, is the phase difference of the lightning to reach the spatial point.

8. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 7, characterized in that, The time delay and phase difference of each radar to the spatial point are calculated based on the coordinate values of each transmitting radar and the spatial point, and the following formula is used: wherein represents the transmit power of the transmitting radar .

9. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 8, characterized in that, The signal of each transmitting radar at the spatial point is calculated based on the full-phase parameters at the target position, the time delay and phase difference of each radar to the spatial point, and the attenuation coefficient, and the following formula is used: 。 10. The distributed full-coherent radar spatial synthetic gain distribution simulation modeling method according to claim 9, characterized in that, The superposition signal of the distributed full-phase radar at the spatial point is calculated based on the signal of each transmitting radar at the spatial point and the first included angle, and the following formula is used: The ratio of the superposition signal power to the signal power of each radar is used, and the following formula is used: wherein is a radar transmission signal.

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