CN103744077A - Angle measurement method of mechanical-scanning meter-wave radar under multi-target condition - Google Patents

Abstract

Translated fromChinese

本发明公开了一种机扫米波雷达在多目标情况下的测角方法，主要解决机扫米波雷达在多目标下用传统单脉冲方法测角精度低的问题。其实现步骤为：1）将天线均分为两个子阵，每个子阵下接一个接收机形成左、右两路通道；2）由左右两路接收通道分别接收雷达发射的脉冲信号；3）对接收的回波信号数据进行杂波目标对消处理；4）将杂波对消后的两路数据相干积累；5）由积累后的两路数据得到和波束与差波束；6）利用传统单脉冲方法测出期望目标的偏轴角，并将偏轴角与基准角相加，得到期望目标的准确角度；7）重复步骤3）-6）依次得到所有目标的准确角度。本发明具有测角精度高，稳健性好，能分辨多个目标的优点，可用于机扫米波雷达多目标检测。

The invention discloses an angle measurement method for a machine-scanned meter-wave radar under the condition of multiple targets, which mainly solves the problem of low accuracy of angle measurement by a traditional single-pulse method for a machine-scanned meter-wave radar under multiple targets. The implementation steps are: 1) Divide the antenna into two sub-arrays, each sub-array is connected with a receiver to form left and right channels; 2) The left and right receiving channels receive the pulse signals transmitted by the radar respectively; 3) Perform clutter target cancellation processing on the received echo signal data; 4) Coherently accumulate the two-way data after clutter cancellation; 5) Obtain the sum beam and difference beam from the accumulated two-way data; 6) Use the traditional The off-axis angle of the desired target is measured by the single-pulse method, and the off-axis angle is added to the reference angle to obtain the accurate angle of the desired target; 7) Repeat steps 3)-6) to obtain the accurate angles of all targets in turn. The invention has the advantages of high angle measurement precision, good robustness and the ability to distinguish multiple targets, and can be used for multi-target detection of machine-scanned meter-wave radars.

Description

Translated fromChinese

机扫米波雷达在多目标情况下的测角方法Angle measurement method of machine-scanned meter wave radar in multi-target situation

技术领域technical field

本发明属于雷达技术领域，特别涉及多目标情况下米波雷达测角方法，可用于机械扫描雷达在多个目标同时存在时，消除各目标之间的相互影响，提高对多个目标的单脉冲测角精度。The invention belongs to the field of radar technology, in particular to a meter wave radar angle measurement method under the condition of multiple targets, which can be used for mechanical scanning radar to eliminate the mutual influence between targets when multiple targets exist at the same time, and improve the single-pulse detection of multiple targets. Angular accuracy.

背景技术Background technique

米波雷达由于信号衰减小，探测距离远，在超视距探测、抗电子干扰等方面具有独特的优势，但同时由于米波雷达的波长较长，波束较宽，使得其角度分辨率差，测角精度低。机械扫描雷达由于成本低，实现简单等因素一直被人们广泛应用。机扫雷达测角方法一般采用最大信号法，但这种方法的精度较差，尤其是对于机扫米波雷达。其电尺寸较小，波束较宽，最大信号法测角精度不高。为了提高测角精度，可以采用单脉冲测角技术。Due to the small signal attenuation and long detection distance, meter wave radar has unique advantages in over-the-horizon detection and anti-electronic interference. However, due to the long wavelength and wide beam of meter wave radar, its angular resolution is poor. Angle measurement accuracy is low. Mechanical scanning radar has been widely used due to factors such as low cost and simple implementation. The angle measurement method of machine-scanned radar generally adopts the maximum signal method, but the accuracy of this method is poor, especially for machine-scanned meter wave radar. Its electrical size is small, the beam is wide, and the angle measurement accuracy of the maximum signal method is not high. In order to improve the accuracy of angle measurement, single-pulse angle measurement technology can be used.

张光义院士在“相控阵雷达原理[M]，北京：国防工业出版社，1994”一书中给出了单脉冲测角方法。单脉冲测角方法是指利用单个脉冲的回波信号就能测出目标真实位置的一类测角方法。在机扫米波雷达中利用幅相和差波束单脉冲方法可以很快的得到目标的准确位置。幅相和差波束单脉冲方法是指把雷达接收的每个脉冲回波经过处理后，得到每个脉冲的和波束与差波束，通过计算差和比，查表可知每个脉冲目标的偏轴角。再加上天线的基准角，就得到单个脉冲测得的目标角度，对所有脉冲测得的角度取平均就是目标的真实位置。Academician Zhang Guangyi gave a monopulse angle measurement method in the book "Principles of Phased Array Radar [M], Beijing: National Defense Industry Press, 1994". The single-pulse angle measurement method refers to a type of angle measurement method that can measure the real position of the target by using the echo signal of a single pulse. In the machine-scanned meter-wave radar, the accurate position of the target can be obtained quickly by using the amplitude-phase and difference beam monopulse method. The single-pulse method of amplitude-phase and difference beam means that after processing each pulse echo received by the radar, the sum beam and difference beam of each pulse are obtained. By calculating the difference and ratio, the off-axis of each pulse target can be known by looking up the table horn. Adding the reference angle of the antenna, the target angle measured by a single pulse is obtained, and the average of the angles measured by all pulses is the true position of the target.

由于幅相和差波束单脉冲方法实现方便，计算量小，测角精度高，在实际应用中具有很大优势。但受机扫米波雷达波束较宽、中心波束对不准目标等缺点的影响，幅相和差波束单脉冲测角方法精度虽然比最大信号法高，但在同一波束宽度或同一距离单元内存在多目标的情况下，由于多目标之间存在相互影响，从而使得传统幅相单脉冲测角方法的测角精度降低，特别在两个目标相距较近时，传统单脉冲测角方法无法分辨目标，达不到对每个目标都准确测角的目的，影响雷达的分辨力和测角准确性。Because the amplitude-phase and difference beam single-pulse method is easy to implement, the amount of calculation is small, and the accuracy of angle measurement is high, it has great advantages in practical applications. However, due to the shortcomings of the wide beam of the aircraft-scanning meter-wave radar and the inaccuracy of the central beam on the target, the accuracy of the amplitude-phase and difference beam single-pulse angle measurement method is higher than that of the maximum signal method. In the case of multiple targets, due to the mutual influence between multiple targets, the angle measurement accuracy of the traditional amplitude-phase single-pulse angle measurement method is reduced, especially when the two targets are close to each other, the traditional single-pulse angle measurement method cannot distinguish target, the purpose of accurately measuring the angle of each target cannot be achieved, which will affect the resolution and angle measurement accuracy of the radar.

发明内容Contents of the invention

本发明的目的是针对上述已有的幅相和差波束单脉冲测角方法的缺点，提出了一种机扫米波雷达在多目标情况下的测角方法，以消除多个目标之间的相互影响，提高在多目标情况下的单脉冲测角精度。The purpose of the present invention is to address the shortcomings of the above-mentioned existing amplitude-phase and difference beam single-pulse angle-measuring methods, and propose a method for measuring the angle of a machine-scanned meter-wave radar under the multi-target situation, so as to eliminate the gap between multiple targets. Influence each other to improve the single-pulse angle measurement accuracy in the case of multiple targets.

为实现上述目的本发明是这样实现的：For realizing the above object, the present invention is achieved like this:

一、技术思路1. Technical ideas

本发明将机扫天线等效成由两个子阵组成的天线面，根据先验得到的各目标的多普勒频率，将其中一个目标作为期望目标，把其他目标视为运动的杂波，通过专门设计的运动目标显示MTI对消器，将其他杂波目标对消掉，只保留期望目标的数据，然后利用传统幅相和差波束单脉冲方法对期望目标进行测角，得到期望目标的偏轴角，加上基准角后得到期望目标的准确角度。In the present invention, the machine-scanning antenna is equivalent to an antenna surface composed of two sub-arrays, and according to the Doppler frequency of each target obtained a priori, one of the targets is regarded as the desired target, and the other targets are regarded as moving clutter. The specially designed moving target display MTI canceller cancels other clutter targets and only retains the data of the desired target, and then uses the traditional amplitude-phase and difference beam single-pulse method to measure the angle of the desired target to obtain the deviation of the desired target The shaft angle, plus the reference angle, gives the exact angle of the desired target.

二、实现步骤2. Implementation steps

根据上述技术思路，本发明的实现步骤如下：According to above-mentioned technical thinking, the realization steps of the present invention are as follows:

（1）将机扫天线等效为由N个阵元组成的天线阵，将天线阵均分为左右两个子阵，每个子阵阵元数均为N/2，左右子阵下各接一路接收机，形成左、右两路接收通道，其中N为大于等于4的偶数；(1) The machine-scanning antenna is equivalent to an antenna array composed of N array elements, and the antenna array is divided into two left and right sub-arrays. The number of elements in each sub-array is N/2, and each of the left and right sub-arrays is connected to one channel. The receiver forms two receiving channels, left and right, wherein N is an even number greater than or equal to 4;

（2）将测角范围-90°～90°每间隔10°划分为一个波位，对于任意一个波位，由左通道的N/2个阵元得到该波位的左通道合成波束B_l，由右通道的N/2个阵元得到该波位的右通道合成波束B_r，由这两个合成波束B_l和B_r得到该波位的鉴角曲线，保存所有波位的鉴角曲线的数据，得到鉴角曲线表；(2) Divide the angle measurement range -90°～90° into a wave position every 10°. For any wave position, the left channel synthetic beam B_l of the wave position is obtained from the N/2 array elements of the left channel , the right channel composite beam B_r of the wave position is obtained from the N/2 array elements of the right channel, the angle discrimination curve of the wave position is obtained from the two synthetic beams B_l and B_r , and the discrimination angles of all wave positions are saved The data of the curve is obtained to obtain the angle discrimination curve table;

（3）设在机扫雷达的一个波束宽度内存在M个运动的目标，将这M个目标依次编号为U₁,...,U_k,...,U_M，得到每个目标的多普勒频率

其中f₀表示雷达发射信号的中心频率，c代表光速，V_k表示每个目标相对于雷达的径向速度，k=1,2,...,M；(3) Assuming that there are M moving targets within one beam width of the machine-scanned radar, these M targets are sequentially numbered U₁ ,...,U_k ,...,_UM , to obtain the Doppler frequency

Where f₀ represents the center frequency of the radar transmitting signal, c represents the speed of light, V_k represents the radial velocity of each target relative to the radar, k=1,2,...,M;

（4）机扫雷达在天线扫描工作时，每间隔0.25°发射一个脉冲，一个波束宽度内共发射L个脉冲；将发射第i个脉冲时，天线中心法线与水平参考面的夹角作为基准角

i，i=1,2,...,L；(4) When the machine-scanning radar is scanning the antenna, it transmits a pulse at an interval of 0.25°, and a total of L pulses are transmitted within one beam width; when the i-th pulse is transmitted, the angle between the normal line of the antenna center and the horizontal reference plane is taken as Reference angle

i, i=1,2,...,L;

（5）由左通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到左通道回波数据(5) Scan the L pulses transmitted by the N/2 array element receivers in the left channel when the antenna is scanning, and obtain the left channel echo data

其中：左通道回波数据T₁中包含了所有目标的回波信息，

表示左通道接收第i个脉冲得到的回波数据，i=1,2,...,L；A_ik=[a(θ_k1),...,a(θ_ki),...,a(θ_kL)]表示左通道接收第k个目标的角度信息，Among them: the left channel echo data T₁ contains the echo information of all targets,

Indicates the echo data obtained by receiving the i-th pulse on the left channel, i=1,2,...,L; A_ik =[a(θ_k1 ),...,a(θ_ki ),..., a(θ_kL )] indicates that the left channel receives the angle information of the kth target,

式中，a(θ_ki)=[1,exp(j2π1d/λsinθ_ki),...,exp(j2π(N/2-1)d/λsinθ_ki)]^T表示左通道接收的第i个脉冲包含的第k个目标的方向矢量，θ_ki表示接收第i个脉冲时第k个目标与天线法线的夹角，称为偏轴角；exp表示以e为底的指数幂，j代表虚数单位，d代表阵元间距，λ代表信号波长，[·]^T表示向量的非共轭转置；In the formula, a(θ_ki )=[1,exp(j2π1d/λsinθ_ki ),...,exp(j2π(N/2-1)d/λsinθ_ki )]^T represents the i-th pulse received by the left channel Included is the direction vector of the k-th target, θ_ki represents the angle between the k-th target and the antenna normal when receiving the i-th pulse, which is called the off-axis angle; exp represents the exponential power with e as the base, and j represents an imaginary number unit, d represents the array element spacing, λ represents the signal wavelength, [ ]^T represents the non-conjugate transpose of the vector;

S_ik=[s_k1,...,s_ki,...,s_kL]^T表示机扫雷达天线接收第k个目标的复包络信息，式中s_ki=exp(j2πf_k(i-1)t)表示第i个脉冲包含的第k个目标的复包络，f_k表示第k个目标的多普勒频率，t表示脉冲重复周期；S_ik =[s_k1 ,...,s_ki ,...,s_kL ]^T represents the complex envelope information of the kth target received by the machine-scanned radar antenna, where s_ki =exp(j2πf_k (i- 1) t) represents the complex envelope of the k-th target included in the i-th pulse, f_k represents the Doppler frequency of the k-th target, and t represents the pulse repetition period;

n₁表示左通道N/2个阵元接收的噪声，其中n₁是均值为0，方差为1的阶随机高斯白噪声；n₁ represents the noise received by N/2 array elements in the left channel, where n₁ is the order random Gaussian white noise with a mean value of 0 and a variance of 1;

（6）由右通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到右通道回波数据

(6) The N/2 array element receivers in the right channel scan the L pulses emitted by the radar when the antenna is scanning, and obtain the echo data of the right channel

其中，右通道回波数据T₂中包含了所有目标的回波信息，

表示右通道接收的第i个脉冲得到的回波数据，式中i=1,2,...,L，G_ik=[g(θ_k1),...,g(θ_ki),...,g(θ_kL)]表示右通道接收的第k个目标的角度信息，Among them, the right channel echo data T₂ contains the echo information of all targets,

Indicates the echo data obtained from the i-th pulse received by the right channel, where i=1,2,...,L, G_ik =[g(θ_k1 ),...,g(θ_ki ),. ..,g(θ_kL )] represents the angle information of the kth target received by the right channel,

式中，g(θ_ki)=[exp(j2π(N/2+1)d/λsinθ_ki),...,exp(j2π(N-1)d/λsinθ_ki)]^T表示右通道接收的第i个脉冲中包含的第k个目标的方向矢量；In the formula, g(θ_ki )=[exp(j2π(N/2+1)d/λsinθ_ki ),...,exp(j2π(N-1)d/λsinθ_ki )]^T represents the The direction vector of the k-th target contained in the i-th pulse;

n₂表示右通道N/2个阵元接收的噪声，其中n₂是均值为0，方差为1的随机高斯白噪声；n₂ represents the noise received by N/2 array elements in the right channel, where n₂ is random Gaussian white noise with a mean value of 0 and a variance of 1;

（7）对接收到的数据做杂波目标对消处理：(7) Perform clutter target cancellation processing on the received data:

7a）将第k个目标U_k标记为期望目标，并把其余目标全部看做运动的杂波目标；7a) Mark the kth target U_k as the desired target, and regard all other targets as moving clutter targets;

7b）将左通道回波数据T₁和右通道回波数据T₂中包含的杂波目标数据全部消掉，即利用运动目标识对显示MTI消器将杂波目标依次对消，其中，MTI对消器计算公式为：7b) Eliminate all the clutter target data contained in the echo data T₁ of the left channel and the echo data T₂ of the right channel, that is, use the moving target identification pair to display the MTI canceller to cancel the clutter targets sequentially, among which, the MTI The formula for calculating the canceller is:

W_l=X_l+1-exp(j2πtf_m)X_l，l=1,2...,L-p，W_l =X_l+1 -exp(j2πtf_m )X_l ，l=1,2...,Lp,

式中，m表示杂波目标U_m的编号，m≠k，f_m表示杂波目标U_m的多普勒频率，X_l表示对消杂波目标U_m前的第l列数据，W_l表示对消杂波目标U_m后得到的第l列数据，p表示对消次数且1≤p≤M；In the formula, m represents the serial number of the clutter target U_m , m≠k, f_m represents the Doppler frequency of the clutter target U_m , X_l represents the data in the first column before canceling the clutter target U_m , W_l Indicates the l-th column of data obtained after canceling the clutter target U_m , p indicates the number of cancellations and 1≤p≤M;

7c）重复利用步骤7b）中所述的MTI对消器将所有杂波目标对消掉，得到只包含期望目标U_k的左通道数据Y₁和只包含期望目标U_k的右通道数据Y₂；7c) Repeatedly use the MTI canceller described in step 7b) to cancel all clutter targets, and obtain the left channel data Y₁ containing only the desired target U_k and the right channel data Y₂ containing only the desired target U_k ;

（8）将只包含期望目标U_k的左通道数据Y₁的全部N/2行进行相干积累，得到左通道积累后的数据Z₁，将只包含期望目标U_k的右通道数据Y₂的全部N/2行进行相干积累，得到右通道积累后的数据Z₂，其中Z₁和Z₂均为1×(L-M)阶矩阵；(8) Coherently accumulate all the N/2 lines of the left channel data Y₁ that only contain the desired target U_k to obtain the accumulated data Z₁ of the left channel, which will only contain the right channel data Y₂ of the desired target U_k All N/2 rows are coherently accumulated to obtain the accumulated data Z₂ of the right channel, where both Z₁ and Z₂ are 1×(LM) order matrices;

（9）对左通道积累后的数据Z₁和右通道积累后的数据Z₂利用和差波束单脉冲方法进行测角，得到期望目标U_k第l个脉冲的目标偏轴角θ_kl，l=1,2，...L-M；(9) Measure the angle of the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel by using the sum-difference beam single-pulse method, and obtain the target off-axis angle θ_kl of the l-th pulse of the desired target U_k , l =1,2,...LM;

（10）将期望目标U_k第l个脉冲的目标偏轴角θ_kl与第l个脉冲的基准角

l相加，得到第l个脉冲对目标的测量角度ψ_kl；(10) Compare the target off-axis angle θ_kl of the l-th pulse of the expected target U_k with the reference angle of the l-th pulse

Add l to get the measurement angle ψ_kl of the l-th pulse to the target;

（11）对由步骤（10）得到的L-M个测量角度ψ_kl取平均，得到期望目标U_k的准确角度Φ_k，${\mathrm{\Φ}}_k=\frac{1}{L-M}\underset{l=1}{\overset{L-M}{\mathrm{\Σ}}}{\mathrm{\ψ}}_{\mathrm{kl}}.$(11) Take the average of the LM measured angles ψ_kl obtained in step (10) to obtain the accurate angle Φ_k of the desired target U_k ,${\mathrm{\Φ}}_k=\frac{1}{L-m}\underset{l=1}{\overset{L-m}{\mathrm{\Σ}}}{\mathrm{\ψ}}_{\mathrm{kl}}.$

本发明与现有技术相比有以下优点：Compared with the prior art, the present invention has the following advantages:

本发明利用运动目标显示MTI技术，针对一个期望目标，将其它目标全部视为运动的杂波目标，并依次通过MTI对消器将杂波目标对消掉，得到只包含期望目标的回波数据，从而消除了目标之间的相互影响，将多目标检测简化为对单目标的角度测量，提高了对多目标的测角精确度，相对于传统单脉冲方法本发明具有更好的稳健性。The present invention utilizes the moving target display MTI technology, for a desired target, regards all other targets as moving clutter targets, and sequentially cancels the clutter targets through the MTI canceller, and obtains echo data containing only the desired target , thereby eliminating the mutual influence between targets, simplifying multi-target detection to angle measurement for a single target, improving the angle measurement accuracy for multiple targets, and the present invention has better robustness compared with the traditional single-pulse method.

附图说明Description of drawings

图1是本发明的实现流程图；Fig. 1 is the realization flowchart of the present invention;

图2是本发明中建立鉴角曲线表的子流程图；Fig. 2 is the sub-flow chart of setting up angle discrimination curve table among the present invention;

图3是本发明中左右通道的和差波束曲线图；Fig. 3 is the sum and difference beam curve diagram of the left and right channels in the present invention;

图4是0°波位的鉴角曲线；Fig. 4 is the angle discrimination curve of 0° wave position;

图5是采用本发明方法与传统幅相单脉冲方法在存在多个目标时对一个目标进行测角的均方根误差对比曲线。Fig. 5 is a comparison curve of the root mean square error of measuring the angle of a target by using the method of the present invention and the traditional amplitude-phase single-pulse method when there are multiple targets.

具体实施方式Detailed ways

参照图1，本发明的具体实施步骤如下：With reference to Fig. 1, concrete implementation steps of the present invention are as follows:

步骤1，将机扫雷达的天线等效为由阵元组成的阵列天线。Step 1, the antenna of the machine-scanned radar is equivalent to an array antenna composed of array elements.

1a）将机扫雷达的天线等效成由N个阵元组成的等距线阵，即任意两个相邻阵元之间的阵元间距d均相等，且为米波雷达发射信号的波长λ的一半，d=λ/2；1a) The antenna of the machine-scanned radar is equivalent to an equidistant linear array composed of N array elements, that is, the array element spacing d between any two adjacent array elements is equal, and it is the wavelength of the signal transmitted by the meter wave radar Half of λ, d=λ/2;

1b）将天线阵均分为左右两个子阵，每个子阵阵元数目均为N/2，且N为大于等于4的偶数；1b) Divide the antenna array into two left and right sub-arrays, the number of elements in each sub-array is N/2, and N is an even number greater than or equal to 4;

1c）左右两个子阵下各接一个接收机，形成左、右两路通道。1c) A receiver is connected to each of the left and right sub-arrays to form left and right channels.

步骤2，设置鉴角曲线表。Step 2, set the angle detection curve table.

参照图2，本步骤的具体实现如下：Referring to Figure 2, the specific implementation of this step is as follows:

2a）将测角范围-90°～90°每间隔10°划分为一个波位；2a) Divide the angle measurement range -90°～90° into a wave position at intervals of 10°;

2b）对于任意一个波位，由左半阵的N/2个阵元得到该波位的左半阵合成波束B_l，由右半阵的N/2个阵元得到该波位的右半阵合成波束B_r；2b) For any wave position, the left half array synthetic beam B_l of this wave position is obtained from the N/2 array elements of the left half array, and the right half of the wave position is obtained from the N/2 array elements of the right half array array synthesized beam B_r ;

2c）由任意一个波位的左半阵合成波束B_l和右半阵合成波束B_r，分别得到该波位的左右半阵和波束B_Σ和左右半阵差波束B_Δ：B_Σ=B_l+B_r，B_Δ=B_l-B_r；2c) From the synthesized beam B_l of the left half array and the synthesized beam B_r of the right half array at any wave position, the left and right half array and beam B_Σ and the left and right half array difference beam B_Δ of the wave position are respectively obtained: B_Σ =B_l +B_r , B_Δ =B_l -B_r ;

2d）根据左右半阵差波束B_Δ和左右半阵和波束B_Σ，计算该波位的差和比：

其中imag(·)表示取虚部运算；2d) According to the difference beam B_Δ of the left and right half array and the sum beam B_Σ of the left and right half array, calculate the difference and ratio of the wave position:

Among them, imag( ) means to take the imaginary part operation;

2e）以该波位的角度范围为横坐标，以差和比为纵坐标，由该波位测角范围对应的差和比画出该波位的鉴角曲线；2e) Take the angle range of the wave position as the abscissa, and the difference and ratio as the ordinate, draw the angle detection curve of the wave position from the difference and ratio corresponding to the angle measurement range of the wave position;

2f）重复步骤2a）到2e），得到所有波位的鉴角曲线，如图4，保存所有鉴角曲线的数据，得到鉴角曲线表。2f) Repeat steps 2a) to 2e) to obtain the angle detection curves of all wave positions, as shown in Figure 4, save the data of all angle detection curves, and obtain the angle detection curve table.

步骤3，设在机扫雷达的一个波束宽度内存在M个运动的目标，将这M个目标依次编号为U₁,...,U_k,...,U_M，得到每个目标的多普勒频率

其中f₀表示雷达发射信号的中心频率，c代表光速，Vk表示每个目标相对于雷达的径向速度，k=1,2,...,M。Step 3, assuming that there are M moving targets within one beam width of the machine-scanned radar, these M targets are sequentially numbered U₁ ,...,U_k ,...,_UM , and each target's Doppler frequency

Where f₀ represents the center frequency of the radar transmission signal, c represents the speed of light, Vk represents the radial velocity of each target relative to the radar, k=1,2,...,M.

步骤4，机扫雷达在天线扫描工作时，每间隔0.25°发射一个脉冲，一个波束宽度内共发射L个脉冲；将发射第i个脉冲时，天线中心法线与水平参考面的夹角作为基准角

i，i=1,2,...,L。Step 4, when the machine-scanned radar is scanning the antenna, it transmits a pulse at an interval of 0.25°, and a total of L pulses are transmitted within a beam width; when the i-th pulse is transmitted, the angle between the normal of the antenna center and the horizontal reference plane is taken as Reference angle

i, i=1,2,...,L.

步骤5，由左通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到左通道回波数据

Step 5: Scan the L pulses transmitted by the radar with N/2 array element receivers in the left channel when the antenna is scanning, and obtain the echo data of the left channel

其中：左通道回波数据T₁中包含了所有目标的回波信息，

表示左通道接收的第i个脉冲得到的回波数据，式中i=1,2,...,L；A_ik=[a(θ_k1),...,a(θ_ki),...,a(θ_kL)]表示左通道接收的第k个目标的角度信息，Among them: the left channel echo data T₁ contains the echo information of all targets,

Indicates the echo data obtained from the i-th pulse received by the left channel, where i=1,2,...,L; A_ik =[a(θ_k1 ),...,a(θ_ki ),. ..,a(θ_kL )] represents the angle information of the kth target received by the left channel,

式中，a(θ_ki)=[1,exp(j2π1d/λsinθ_ki),...,exp(j2π(N/2-1)d/λsinθ_ki)]^T表示左通道接收的第i个脉冲包含的第k个目标的方向矢量，θ_ki表示接收第i个脉冲时第k个目标与天线法线的夹角，称为偏轴角；exp表示以e为底的指数幂，j代表虚数单位，d代表阵元间距，λ代表信号波长，[·]^T表示向量的非共轭转置；In the formula, a(θ_ki )=[1,exp(j2π1d/λsinθ_ki ),...,exp(j2π(N/2-1)d/λsinθ_ki )]^T represents the i-th pulse received by the left channel Included is the direction vector of the k-th target, θ_ki represents the angle between the k-th target and the antenna normal when receiving the i-th pulse, which is called the off-axis angle; exp represents the exponential power with e as the base, and j represents an imaginary number unit, d represents the array element spacing, λ represents the signal wavelength, [ ]^T represents the non-conjugate transpose of the vector;

S_ik=[s_k1,...,s_ki,...,s_kL]^T表示机扫雷达天线接收第k个目标的复包络信息，式中s_ki=exp(j2πf_k(i-1)t)表示第i个脉冲包含的第k个目标的复包络，f_k表示第k个目标的多普勒频率，t表示脉冲重复周期；S_ik =[s_k1 ,...,s_ki ,...,s_kL ]^T represents the complex envelope information of the kth target received by the machine-scanned radar antenna, where s_ki =exp(j2πf_k (i- 1) t) represents the complex envelope of the k-th target included in the i-th pulse, f_k represents the Doppler frequency of the k-th target, and t represents the pulse repetition period;

n₁表示左通道N/2个阵元接收的噪声，其中n₁是均值为0，方差为1的随机高斯白噪声。n₁ represents the noise received by N/2 array elements in the left channel, where n₁ is random Gaussian white noise with a mean value of 0 and a variance of 1.

步骤6，由右通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到右通道回波数据

Step 6: The N/2 array element receivers in the right channel scan the L pulses transmitted by the radar when the antenna is scanning, and obtain the echo data of the right channel

其中，右通道回波数据T₂中包含了所有目标的回波信息，表示右通道接收的第i个脉冲得到的回波数据，式中i=1,2,...,L，G_ik=[g(θ_k1),...,g(θ_ki),...,g(θ_kL)]表示右通道接收的第k个目标的角度信息，Among them, the right channel echo data T₂ contains the echo information of all targets, Indicates the echo data obtained from the i-th pulse received by the right channel, where i=1,2,...,L, G_ik =[g(θ_k1 ),...,g(θ_ki ),. ..,g(θ_kL )] represents the angle information of the kth target received by the right channel,

式中，g(θ_ki)=[exp(j2π(N/2+1)d/λsinθ_ki),...,exp(j2π(N-1)d/λsinθ_ki)]^T表示右通道接收的第i个脉冲中包含的第k个目标的方向矢量；In the formula, g(θ_ki )=[exp(j2π(N/2+1)d/λsinθ_ki ),...,exp(j2π(N-1)d/λsinθ_ki )]^T represents the The direction vector of the k-th target contained in the i-th pulse;

n₂表示右通道N/2个阵元接收的噪声，其中n₂是均值为0，方差为1的随机高斯白噪声。n₂ represents the noise received by N/2 array elements in the right channel, where n₂ is random Gaussian white noise with a mean value of 0 and a variance of 1.

步骤7，对接收到的数据进行杂波目标对消处理。Step 7, performing clutter target cancellation processing on the received data.

7a）将第k个目标U_k标记为期望目标，并把其余目标全部看做运动的杂波目标；7a) Mark the kth target U_k as the desired target, and regard all other targets as moving clutter targets;

7b）将左通道回波数据T₁和右通道回波数据T₂中包含的杂波目标数据全部消掉，即利用运动目标显示MTI对消器将杂波目标依次对消，其中，MTI对消器计算公式为：7b) Eliminate all the clutter target data contained in the echo data T₁ of the left channel and the echo data T₂ of the right channel, that is, use the moving target display MTI canceller to cancel the clutter targets sequentially, among which, the MTI The formula for calculating the eliminater is:

W_l=X_l+1-exp(j2πtf_m)X_l，l=1,2...,L-p，W_l =X_l+1 -exp(j2πtf_m )X_l ，l=1,2...,Lp,

式中，m表示杂波目标U_m的编号，m≠k，f_m表示杂波目标U_m的多普勒频率，X_l表示对消杂波目标U_m前的第l列数据，W_l表示对消杂波目标U_m后得到的第l列数据，p表示对消次数且1≤p≤M；In the formula, m represents the serial number of the clutter target U_m , m≠k, f_m represents the Doppler frequency of the clutter target U_m , X_l represents the data in the first column before canceling the clutter target U_m , W_l Indicates the l-th column of data obtained after canceling the clutter target U_m , p indicates the number of cancellations and 1≤p≤M;

7c）重复步骤7b）对所有杂波目标进行对消，得到只包含期望目标U_k的左通道数据Y₁和只包含期望目标U_k的右通道数据Y₂。7c) Step 7b) is repeated to cancel all the clutter targets to obtain the left channel data Y₁ containing only the desired target U_k and the right channel data Y₂ containing only the desired target U_k .

步骤8，对杂波目标对消后的两路通道数据进行子阵级相干积累。Step 8, perform subarray-level coherent accumulation on the two channels of channel data after clutter target cancellation.

8a）对只包含期望目标U_k的左通道数据Y₁的全部N/2行进行求和，得到左通道积累后的数据Z₁，Z₁为1×(L-M)阶矩阵；8a) Sum all the N/2 rows of the left channel data Y₁ containing only the desired target U_k to obtain the accumulated data Z₁ of the left channel, and Z₁ is a matrix oforder 1×(LM);

8b）对只包含期望目标U_k的右通道数据Y₂的全部N/2行进行求和，得到右通道积累后的数据Z₂，Z₂为1×(L-M)阶矩阵。8b) Sum all the N/2 rows of the right channel data Y₂ containing only the desired target U_k to obtain the accumulated right channel data Z₂ , where Z₂ is a matrix oforder 1×(LM).

步骤9，对相干积累后的数据进行和差波束单脉冲测角。Step 9, performing sum-difference beam monopulse angle measurement on the coherently accumulated data.

9a）由左通道积累后的数据Z₁和右通道积累后的数据Z₂，得到只包含期望目标U_k的和波束：P_Σ=Z₁+Z₂；9a) From the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel, a sum beam containing only the desired target U_k is obtained: P_Σ =Z₁ +Z₂ ;

9b）由左通道积累后的数据Z₁和右通道积累后的数据Z₂，得到只包含期望目标U_k的差波束：P_Δ=Z₁-Z₂；9b) From the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel, a difference beam containing only the desired target U_k is obtained: P_Δ =Z₁ -Z₂ ;

9c）利用步骤9a）得到的和波束P_Σ和步骤9b）得到的差波束P_Δ，计算差和比：由差和比P的值通过查询步骤2得到查鉴角曲线表，得到期望目标U_k第l个脉冲的目标偏轴角θ_kl，l=1,2，...L-M，其中imag(·)表示取虚部运算。9c) Using the sum beam P_Σ obtained in step 9a) and the difference beam P_Δ obtained in step 9b), calculate the difference sum ratio: From the value of the difference and ratio P, obtain the check angle curve table throughquery step 2, and obtain the target off-axis angle θ_kl of the lth pulse of the expected target U_k , l=1, 2, ... LM, where imag(· ) means to take the imaginary part operation.

步骤10，根据期望目标U_k第l个脉冲的目标偏轴角θ_kl和第l个脉冲的基准角

l，得到第l个脉冲对期望目标U_k的测量角度

l=1,2，...L-M。Step 10, according to the target off-axis angle θ_kl of the l-th pulse of the expected target U_k and the reference angle of the l-th pulse

l, get the measured angle of the lth pulse to the desired target U_k

l=1,2,...LM.

步骤11，对由步骤10得到的L-M个测量角度ψ_kl取平均，得到期望目标U_k的精确角度Φ_k：Step 11, take the average of the LM measurement angles ψ_kl obtained instep 10, and obtain the precise angle Φ_k of the desired target U_k :

${\mathrm{<span><span>\&Phi;</span>\&Phi;</span>}}_{\mathrm{<span><span>k</span>k</span>}}<span><span>=</span>=</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>L</span>L</span>}<span><span>-</span>-</span>\mathrm{<span><span>M</span>m</span>}}\underset{\mathrm{<span><span>l</span>l</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}}{\overset{\mathrm{<span><span>L</span>L</span>}<span><span>-</span>-</span>\mathrm{<span><span>M</span>m</span>}}{\mathrm{<span><span>\&Sigma;</span>\&Sigma;</span>}}}{\mathrm{<span><span>\&psi;</span>\&psi;</span>}}_{\mathrm{<span><span>kl</span>kl</span>}}<span><span>.</span>.</span>$

本发明的效果可以通过以下计算机仿真进行验证：Effect of the present invention can be verified by following computer simulation:

一，仿真条件1. Simulation conditions

仿真条件：假设天线等效为8个阵元组成的天线阵面，分成两个子阵，每个子阵4个阵元，天线的波束宽度约为12°，天线以1.25rad/s的速度进行旋转扫描，雷达每隔3.5ms发射一个脉冲信号，雷达发射信号的中心频率为300MHz，，天线在一个波束宽度内每次接收49个脉冲信号；Simulation conditions: Assume that the antenna is equivalent to an antenna array composed of 8 array elements, divided into two sub-arrays, each sub-array has 4 array elements, the beam width of the antenna is about 12°, and the antenna rotates at a speed of 1.25rad/s Scanning, the radar transmits a pulse signal every 3.5ms, the center frequency of the radar transmission signal is 300MHz, and the antenna receives 49 pulse signals each time within a beam width;

假设存在两个目标，且第一个目标的真实角度为20°，第二个目标的真实角度为29.5°，第一个目标相对雷达的径向速度为100m/s，多普勒频率为200Hz；第二个目标相对雷达的径向速度为300m/s，多普勒频率为600Hz，单个阵元的信噪比取-10dB到20dB。Suppose there are two targets, and the real angle of the first target is 20°, the real angle of the second target is 29.5°, the radial velocity of the first target relative to the radar is 100m/s, and the Doppler frequency is 200Hz ; The radial velocity of the second target relative to the radar is 300m/s, the Doppler frequency is 600Hz, and the signal-to-noise ratio of a single array element is -10dB to 20dB.

二，仿真内容Second, the simulation content

仿真1，根据图2流程，利用仿真条件分别产生传统单脉冲测角方法的和差波束曲线及鉴角曲线，分别如图3和图4所示，其中图3横坐标为角度，纵坐标为幅度；图4横坐标为角度，纵坐标为差和比。Simulation 1, according to the flow chart in Figure 2, use the simulation conditions to generate the sum-difference beam curve and the angle detection curve of the traditional single-pulse angle measurement method, respectively, as shown in Figure 3 and Figure 4, where the abscissa in Figure 3 is the angle, and the ordinate is Amplitude; the abscissa in Figure 4 is the angle, and the ordinate is the difference and ratio.

由图3可见，当天线中心法线对准目标时，回波信号的和波束在幅度最大位置，差波束在幅度最小位置。如果天线没对准目标则不会出现这种情况。It can be seen from Figure 3 that when the normal line of the antenna center is aligned with the target, the sum beam of the echo signal is at the maximum amplitude position, and the difference beam is at the minimum amplitude position. This is not the case if the antenna is not on target.

由图4可见，当天线中心法线对准目标时，和差波束的差和比为0，这与图3中所示的情形相吻合，对照图3可以发现，在天线中心法线对准目标时，回波的差波束幅度为0，则其差和比必然为0；类似地，如果天线中心法线没有对准目标时，则差和比会有偏差，另外，图4所示的鉴角曲线可以作为本发明方法的查表依据。It can be seen from Figure 4 that when the antenna center normal is aligned with the target, the difference sum ratio of the sum-difference beam is 0, which is consistent with the situation shown in Figure 3. Comparing with Figure 3, it can be found that when the antenna center normal is aligned When the target, the difference beam amplitude of the echo is 0, then the difference sum ratio must be 0; similarly, if the antenna center normal is not aligned with the target, the difference sum ratio will deviate. In addition, the difference sum ratio shown in Figure 4 The angle discrimination curve can be used as the table look-up basis of the method of the present invention.

仿真2，利用上述条件在多目标存在的情况下进行测角，得到两种方法随信噪比变化的均方根误差曲线，如图5所示，图5中是对第一个目标测角的均方根误差曲线，图5中横坐标为信噪比，纵坐标为均方根误差。Simulation 2, use the above conditions to measure angles in the presence of multiple targets, and obtain the root mean square error curves of the two methods as the signal-to-noise ratio changes, as shown in Figure 5, which is the angle measurement of the first target The root mean square error curve of Fig. 5 is the signal-to-noise ratio on the abscissa, and the root mean square error on the ordinate.

由图5可见，本发明方法比传统的单脉冲算法精度要高，特别是在信噪比低的情况下，效果非常明显。在机扫雷达存在多个目标时，传统的单脉冲方法受其它目标的影响较大。由于在高信噪比的时候噪声对第一个目标的影响变小，但第二个目标仍对第一个目标存在影响，所以传统单脉冲的回波数据均方根误差曲线会趋近于平直，本发明提出的方法在多个目标存在的情况下，通过MTI对消器得到期望目标的回波数据，再对期望目标进行测角，可以消除多目标之间存在的相互影响，提高单脉冲测角精度，且无论存在多少个目标，都能对目标进行分辨和测角，具有良好的稳健性。It can be seen from Fig. 5 that the accuracy of the method of the present invention is higher than that of the traditional single-pulse algorithm, especially in the case of low signal-to-noise ratio, the effect is very obvious. When there are multiple targets in the machine-scanned radar, the traditional monopulse method is greatly affected by other targets. Since the influence of noise on the first target becomes smaller when the signal-to-noise ratio is high, but the second target still has an impact on the first target, the root mean square error curve of the echo data of the traditional single pulse tends to be Straight, the method proposed in the present invention can get the echo data of the desired target through the MTI canceller in the case of multiple targets, and then measure the angle of the desired target, which can eliminate the mutual influence between multiple targets and improve Single-pulse angle measurement accuracy, and no matter how many targets exist, it can distinguish and measure the angle of the target, with good robustness.

Claims (4)

Translated fromChinese

1.一种机扫米波雷达在多目标情况下的测角方法，包括如下步骤：1. A method for measuring the angle of a machine-scanned meter wave radar under multi-target situations, comprising the steps:（1）将机扫天线等效为由N个阵元组成的天线阵，将天线阵均分为左右两个子阵，每个子阵阵元数均为N/2，左右子阵下各接一路接收机，形成左、右两路接收通道，其中N为大于等于4的偶数；(1) The machine-scanning antenna is equivalent to an antenna array composed of N array elements, and the antenna array is divided into two left and right sub-arrays. The number of elements in each sub-array is N/2, and each of the left and right sub-arrays is connected to one channel. The receiver forms two receiving channels, left and right, wherein N is an even number greater than or equal to 4;（2）将测角范围-90°～90°每间隔10°划分为一个波位，对于任意一个波位，由左通道的N/2个阵元得到该波位的左通道合成波束B_l，由右通道的N/2个阵元得到该波位的右通道合成波束B_r，由这两个合成波束B_l和B_r得到该波位的鉴角曲线，保存所有波位的鉴角曲线的数据，得到鉴角曲线表；(2) Divide the angle measurement range -90°～90° into a wave position every 10°. For any wave position, the left channel synthetic beam B_l of the wave position is obtained from the N/2 array elements of the left channel , the right channel composite beam B_r of the wave position is obtained from the N/2 array elements of the right channel, the angle discrimination curve of the wave position is obtained from the two synthetic beams B_l and B_r , and the discrimination angles of all wave positions are saved The data of the curve is obtained to obtain the angle discrimination curve table;（3）设在机扫雷达的一个波束宽度内存在M个运动的目标，将这M个目标依次编号为U₁,...,U_k,...,U_M，得到每个目标的多普勒频率

其中f₀表示雷达发射信号的中心频率，c代表光速，V_k表示每个目标相对于雷达的径向速度，k=1,2,...,M；(3) Assuming that there are M moving targets within one beam width of the machine-scanned radar, these M targets are sequentially numbered U₁ ,...,U_k ,...,_UM , to obtain the Doppler frequency

Where f₀ represents the center frequency of the radar transmitting signal, c represents the speed of light, V_k represents the radial velocity of each target relative to the radar, k=1,2,...,M;（4）机扫雷达在天线扫描工作时，每间隔0.25°发射一个脉冲，一个波束宽度内共发射L个脉冲；将发射第i个脉冲时，天线中心法线与水平参考面的夹角作为基准角

i=1,2,...,L；(4) When the machine-scanning radar is scanning the antenna, it transmits a pulse at an interval of 0.25°, and a total of L pulses are transmitted within one beam width; when the i-th pulse is transmitted, the angle between the normal line of the antenna center and the horizontal reference plane is taken as Reference angle

i=1,2,...,L;（5）由左通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到左通道回波数据(5) Scan the L pulses transmitted by the N/2 array element receivers in the left channel when the antenna is scanning, and obtain the left channel echo data其中：左通道回波数据T₁中包含了所有目标的回波信息，

表示左通道接收第i个脉冲得到的回波数据，i=1,2,...,L；A_ik=[a(θ_k1),...,a(θ_ki),...,a(θ_kL)]表示左通道接收第k个目标的角度信息，Among them: the left channel echo data T₁ contains the echo information of all targets,

Indicates the echo data obtained by receiving the i-th pulse on the left channel, i=1,2,...,L; A_ik =[a(θ_k1 ),...,a(θ_ki ),..., a(θ_kL )] indicates that the left channel receives the angle information of the kth target,式中，a(θ_ki)=[1,exp(j2π1d/λsinθ_ki),...,exp(j2π(N/2-1)d/λsinθ_ki)]^T表示左通道接收的第i个脉冲包含的第k个目标的方向矢量，θ_ki表示接收第i个脉冲时第k个目标与天线法线的夹角，称为偏轴角；exp表示以e为底的指数幂，j代表虚数单位，d代表阵元间距，λ代表信号波长，[·]^T表示向量的非共轭转置；In the formula, a(θ_ki )=[1,exp(j2π1d/λsinθ_ki ),...,exp(j2π(N/2-1)d/λsinθ_ki )]^T represents the i-th pulse received by the left channel Included is the direction vector of the k-th target, θ_ki represents the angle between the k-th target and the antenna normal when receiving the i-th pulse, which is called the off-axis angle; exp represents the exponential power with e as the base, and j represents an imaginary number unit, d represents the array element spacing, λ represents the signal wavelength, [ ]^T represents the non-conjugate transpose of the vector;S_ik=[s_k1,...,s_ki,...,s_kL]^T表示机扫雷达天线接收第k个目标的复包络信息，式中s_ki=exp(j2πf_k(i-1)t)表示第i个脉冲包含的第k个目标的复包络，f_k表示第k个目标的多普勒频率，t表示脉冲重复周期；S_ik =[s_k1 ,...,s_ki ,...,s_kL ]^T represents the complex envelope information of the kth target received by the machine-scanned radar antenna, where s_ki =exp(j2πf_k (i- 1) t) represents the complex envelope of the k-th target included in the i-th pulse, f_k represents the Doppler frequency of the k-th target, and t represents the pulse repetition period;n₁表示左通道N/2个阵元接收的噪声，其中n₁是均值为0，方差为1的阶随机高斯白噪声；n₁ represents the noise received by N/2 array elements in the left channel, where n₁ is the order random Gaussian white noise with a mean value of 0 and a variance of 1;（6）由右通道的N/2个阵元接收机扫雷达在天线扫描工作时发射的L个脉冲，得到右通道回波数据(6) The N/2 array element receivers in the right channel scan the L pulses emitted by the radar when the antenna is scanning, and obtain the echo data of the right channel其中，右通道回波数据T₂中包含了所有目标的回波信息，

表示右通道接收的第i个脉冲得到的回波数据，式中i=1,2,...,L，G_ik=[g(θ_k1),...,g(θ_ki),...,g(θ_kL)]表示右通道接收的第k个目标的角度信息，Among them, the right channel echo data T₂ contains the echo information of all targets,

Indicates the echo data obtained from the i-th pulse received by the right channel, where i=1,2,...,L, G_ik =[g(θ_k1 ),...,g(θ_ki ),. ..,g(θ_kL )] represents the angle information of the kth target received by the right channel,式中，g(θ_ki)=[exp(j2π(N/2+1)d/λsinθ_ki),...,exp(j2π(N-1)d/λsinθ_ki)]^T表示右通道接收的第i个脉冲中包含的第k个目标的方向矢量；In the formula, g(θ_ki )=[exp(j2π(N/2+1)d/λsinθ_ki ),...,exp(j2π(N-1)d/λsinθ_ki )]^T represents the The direction vector of the k-th target contained in the i-th pulse;n₂表示右通道N/2个阵元接收的噪声，其中n₂是均值为0，方差为1的随机高斯白噪声；n₂ represents the noise received by N/2 array elements in the right channel, where n₂ is random Gaussian white noise with a mean value of 0 and a variance of 1;（7）对接收到的数据做杂波目标对消处理：(7) Perform clutter target cancellation processing on the received data:7a）将第k个目标U_k标记为期望目标，并把其余目标全部看做运动的杂波目标；7a) Mark the kth target U_k as the desired target, and regard all other targets as moving clutter targets;7b）将左通道回波数据T₁和右通道回波数据T₂中包含的杂波目标数据全部消掉，即利用运动目标识对显示MTI消器将杂波目标依次对消，其中，MTI对消器计算公式为：7b) Eliminate all the clutter target data contained in the echo data T₁ of the left channel and the echo data T₂ of the right channel, that is, use the moving target identification pair to display the MTI canceller to cancel the clutter targets sequentially, among which, the MTI The formula for calculating the canceller is:W_l=X_l+1-exp(j2πtf_m)X_l，l=1,2...,L-p，W_l =X_l+1 -exp(j2πtf_m )X_l ，l=1,2...,Lp,式中，m表示杂波目标U_m的编号，m≠k，f_m表示杂波目标U_m的多普勒频率，X_l表示对消杂波目标U_m前的第l列数据，W_l表示对消杂波目标U_m后得到的第l列数据，p表示对消次数且1≤p≤M；In the formula, m represents the serial number of the clutter target U_m , m≠k, f_m represents the Doppler frequency of the clutter target U_m , X_l represents the data in the first column before canceling the clutter target U_m , W_l Indicates the l-th column of data obtained after canceling the clutter target U_m , p indicates the number of cancellations and 1≤p≤M;7c）重复利用步骤7b）中所述的MTI对消器将所有杂波目标对消掉，得到只包含期望目标U_k的左通道数据Y₁和只包含期望目标U_k的右通道数据Y₂；7c) Repeatedly use the MTI canceller described in step 7b) to cancel all clutter targets, and obtain the left channel data Y₁ containing only the desired target U_k and the right channel data Y₂ containing only the desired target U_k ;（8）将只包含期望目标U_k的左通道数据Y₁的全部N/2行进行相干积累，得到左通道积累后的数据Z₁，将只包含期望目标U_k的右通道数据Y₂的全部N/2行进行相干积累，得到右通道积累后的数据Z₂，其中Z₁和Z₂均为1×(L-M)阶矩阵；(8) Coherently accumulate all the N/2 lines of the left channel data Y₁ that only contain the desired target U_k to obtain the accumulated data Z₁ of the left channel, which will only contain the right channel data Y₂ of the desired target U_k All N/2 rows are coherently accumulated to obtain the accumulated data Z₂ of the right channel, where both Z₁ and Z₂ are 1×(LM) order matrices;（9）对左通道积累后的数据Z₁和右通道积累后的数据Z₂利用和差波束单脉冲方法进行测角，得到期望目标U_k第l个脉冲的目标偏轴角θ_kl，l=1,2，...L-M；(9) Measure the angle of the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel by using the sum-difference beam single-pulse method, and obtain the target off-axis angle θ_kl of the l-th pulse of the desired target U_k , l =1,2,...LM;（10）将期望目标U_k第l个脉冲的目标偏轴角θ_kl与第l个脉冲的基准角

相加，得到第l个脉冲对目标的测量角度ψ_kl；(10) Compare the target off-axis angle θ_kl of the l-th pulse of the expected target U_k with the reference angle of the l-th pulse

Add up to get the measured angle ψ_kl of the lth pulse to the target;（11）对由步骤（10）得到的L-M个测量角度ψ_kl取平均，得到期望目标U_k的准确角度Φ_k，${\mathrm{\&Phi;}}_k=\frac{1}{L-M}\underset{l=1}{\overset{L-M}{\mathrm{\&Sigma;}}}{\mathrm{\&psi;}}_{\mathrm{kl}}.$(11) Take the average of the LM measured angles ψ_kl obtained in step (10) to obtain the accurate angle Φ_k of the desired target U_k ,${\mathrm{\&Phi;}}_k=\frac{1}{L-m}\underset{l=1}{\overset{L-m}{\mathrm{\&Sigma;}}}{\mathrm{\&psi;}}_{\mathrm{kl}}.$2.根据权利要求1所述的机扫米波雷达在多目标情况下的测角方法，其特征在于，步骤（1）所述的将机扫天线等效为由N个阵元组成的天线阵，是先将机扫雷达的天线等效成由N个阵元组成的等距线阵，即任意两个相邻阵元之间的阵元间距d均相等，且为米波雷达发射信号的波长λ的一半，d=λ/2；再将等距线阵均分为左右两个半阵，左半阵与右半阵的阵元数均为N/2，每个半阵下各接一个接收机，形成左、右两路接收通道，其中N为总阵元数，取值为N≥4的偶数。2. The angle measurement method of the machine-scanned meter-wave radar in the case of multiple targets according to claim 1, characterized in that the machine-scanned antenna described in step (1) is equivalent to an antenna composed of N array elements Array, the antenna of the machine-scanned radar is first equivalent to an equidistant linear array composed of N array elements, that is, the array element spacing d between any two adjacent array elements is equal, and the signal is transmitted by the meter wave radar half of the wavelength λ, d=λ/2; then the equidistant linear array is divided into left and right half arrays, the number of array elements in the left half array and the right half array is N/2, each half array Connect a receiver to form left and right receiving channels, where N is the total number of array elements, and the value is an even number of N≥4.3.根据权利要求1所述的机扫米波雷达在多目标情况下的测角方法，其特征在于，所述步骤（2）中由划分后的任意一个波位的左半阵合成波束B_l和右半阵合成波束B_r，得到该波位的鉴角曲线，按如下步骤进行：3. The angle measurement method of machine-scanning meter-wave radar in the case of multiple targets according to claim 1, characterized in that, in the step (2), the beam B is synthesized by the left half array of any wave position after division_l and the right half array synthesize the beam B_r to obtain the angle discrimination curve of the wave position, proceed as follows:2a）由任意一个波位的左半阵合成波束B_l和右半阵合成波束B_r，分别得到该波位的左右半阵和波束B_Σ和左右半阵差波束B_Δ：B_Σ=B_l+B_r，B_Δ=B_l-B_r；2a) From the synthesized beam B_l of the left half array and the synthesized beam B_r of the right half array at any wave position, the left and right half array and beam B_Σ and the left and right half array difference beam B_Δ of the wave position are respectively obtained: B_Σ =B_l +B_r , B_Δ =B_l -B_r ;2b）根据左右半阵差波束B_Δ和左右半阵和波束B_Σ，计算该波位的差和比：

其中imag(·)表示取虚部运算；2b) According to the difference beam B_Δ of the left and right half array and the sum beam B_Σ of the left and right half array, calculate the difference and ratio of the wave positions:

Among them, imag( ) means to take the imaginary part operation;2c）以该波位的角度范围为横坐标，以差和比为纵坐标，由该波位测角范围对应的差和比画出该波位的鉴角曲线。2c) Taking the angle range of the wave position as the abscissa and the difference and ratio as the ordinate, draw the angle detection curve of the wave position from the difference and ratio corresponding to the angle measurement range of the wave position.4.根据权利要求1所述的机扫米波雷达在多目标情况下的测角方法，其特征在于，步骤（9）中所述的对左通道积累后的数据Z₁和右通道积累后的数据Z₂利用和差波束单脉冲方法进行测角，按如下步骤进行：4. the angle measuring method of machine-scanning meter-wave radar according to claim 1 under multi-target situation, is characterized in that, described in step (9) to the data_Z after left channel accumulation and after right channel accumulation The data Z₂ uses the sum-difference beam monopulse method to measure the angle, as follows:9a）由左通道积累后的数据Z₁和右通道积累后的数据Z₂得到只包含期望目标U_k的和波束：P_Σ=Z₁+Z₂；9a) From the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel, the sum beam containing only the desired target U_k is obtained: P_Σ =Z₁ +Z₂ ;9b）由左通道积累后的数据Z₁和右通道积累后的数据Z₂得到只包含期望目标U_k的差波束：P_Δ=Z₁-Z₂；9b) From the data Z₁ accumulated in the left channel and the data Z₂ accumulated in the right channel, a difference beam containing only the desired target U_k is obtained: P_Δ =Z₁ -Z₂ ;9c）由只包含期望目标U_k的和波束P_Σ与只包含期望目标U_k的差波束P_Δ，得到差和比：由差和比P的值通过查鉴角曲线表，得到期望目标k第l个脉冲的目标偏轴角θ_kl，其中imag(·)表示取虚部运算，l=1,2，...L-M。9c) From the sum beam P_Σ containing only the desired target U_k and the difference beam P_Δ containing only the desired target U_k , the difference sum ratio is obtained: The target off-axis angle θ_kl of the lth pulse of the desired target k is obtained by looking up the angle curve table from the value of the difference and ratio P, where imag( ) means taking the imaginary part operation, l=1,2,... Lm.

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