CN104515982A

CN104515982A - Bistatic airborne radar clutter compensation method and device based on derivative updating

Info

Publication number: CN104515982A
Application number: CN201410745210.3A
Authority: CN
Inventors: 文珺; 赵进创; 邹星星; 宋玲; 许京伟
Original assignee: Guangxi University
Current assignee: Guangxi University
Priority date: 2014-12-08
Filing date: 2014-12-08
Publication date: 2015-04-15

Abstract

The invention discloses a bistatic airborne radar clutter compensation method and device based on derivative update, wherein the method includes: receiving the echo signal of the bistatic airborne radar, and calculating the Kth echo signal to be detected The sum of the sending and receiving distances of the range gates; according to the sum of the sending and receiving distances of the Kth range gates to be detected, calculate the receiving pitch angle cosine of the main lobe direction; according to the receiving distance or the pitch angle of the main lobe direction, calculate the self of the derivative update Adapting the weight vector: Compensating the echo signal according to the adaptive weight vector. The bistatic airborne radar clutter compensation method and device based on derivative update of the present invention realizes the processing based on derivative update under the bistatic condition, and after using the method to compensate the echo data, it can effectively reduce the noise of the bistatic airborne radar. The distance dependence can greatly improve the ground moving target detection performance of space-time adaptive processing, and greatly improve the working efficiency of radar detection.

Description

A Bistatic Airborne Radar Clutter Compensation Method and Device Based on Derivative Update

技术领域technical field

本发明涉及雷达通信技术领域，具体地，涉及一种基于导数更新的双基机载雷达杂波补偿方法和装置。The present invention relates to the technical field of radar communication, in particular to a method and device for compensating clutter of bistatic airborne radar based on derivative update.

背景技术Background technique

双基机载雷达的发射机系统和接收机系统安装在不同的载机平台上，相对于普通单机载雷达，其具有获取信息丰富、作用距离远、安全性高、抗干扰能力强和抗截获性能好等优点。The transmitter system and receiver system of bistatic airborne radar are installed on different airborne platforms. Compared with ordinary single airborne radar, it has the advantages of rich information acquisition, long range, high security, strong anti-interference ability and anti-interception Good performance and other advantages.

但是，双机载雷达接收端的雷达回波空时两维功率谱具有自身的缺陷：1、存在严重的距离依赖性；2、不同载机构型形状存在明显的差异。上述问题使得传统的地面动目标检测性能严重下降，也即无法有效抑制地杂波，使得地面运动目标难以被检测出来。However, the space-time two-dimensional power spectrum of the radar echo at the receiving end of the dual airborne radar has its own defects: 1. There is a serious distance dependence; 2. There are obvious differences in the configuration and shape of different aircraft. The above problems seriously degrade the performance of traditional ground moving target detection, that is, the ground clutter cannot be effectively suppressed, making it difficult to detect ground moving targets.

发明内容Contents of the invention

为了解决现有技术中双基机载雷达通信时无法有效抑制地杂波的问题，本发明提出了一种基于导数更新的双基机载雷达杂波补偿方法和装置。In order to solve the problem that the ground clutter cannot be effectively suppressed in the communication of the bistatic airborne radar in the prior art, the present invention proposes a method and device for compensating the clutter of the bistatic airborne radar based on derivative update.

该方法，包括：The method, including:

接收双基机载雷达的回波信号，计算所述回波信号第K个待检测距离门的收发距离之和；Receiving the echo signal of the bistatic airborne radar, calculating the sum of the sending and receiving distances of the Kth range gate to be detected of the echo signal;

根据所述第K个待检测距离门的收发距离之和，计算主瓣方向的接收俯仰角余弦；According to the sum of the sending and receiving distances of the Kth range gate to be detected, calculate the receiving pitch angle cosine of the main lobe direction;

根据主瓣方向的接收距离或俯仰角，计算导数更新的自适应权矢量；Calculate the adaptive weight vector for derivative update according to the receiving distance or pitch angle of the main lobe direction;

根据所述自适应权矢量对所述回波信号进行补偿。The echo signal is compensated according to the adaptive weight vector.

本发明的基于导数更新的双基机载雷达杂波补偿方法，在双基条件下实现基于导数更新的处理，利用该方法对回波数据进行补偿后，能够有效降低双基机载雷达的距离依赖性，进而大大提高空时自适应处理的地面动目标检测性能，极大的提高了雷达检测的工作效率。The bistatic airborne radar clutter compensation method based on the derivative update of the present invention realizes the processing based on the derivative update under the bistatic condition, and after the echo data is compensated by using the method, the distance of the bistatic airborne radar can be effectively reduced Dependency, and then greatly improve the ground moving target detection performance of space-time adaptive processing, and greatly improve the efficiency of radar detection.

该装置，包括：The device, including:

第一计算模块，用于接收双基机载雷达的回波信号，计算所述回波信号第K个待检测距离门的收发距离之和；The first calculation module is used to receive the echo signal of the bistatic airborne radar, and calculate the sum of the sending and receiving distances of the Kth range gate to be detected in the echo signal;

第二计算模块，用于根据所述第K个待检测距离门的收发距离之和，计算主瓣方向的接收俯仰角余弦；The second calculation module is used to calculate the receiving pitch angle cosine of the main lobe direction according to the sum of the transmitting and receiving distances of the Kth range gate to be detected;

第三计算模块，用于根据主瓣方向的接收距离或俯仰角，计算导数更新的自适应权矢量；The third calculation module is used to calculate the adaptive weight vector of derivative update according to the receiving distance or pitch angle of the main lobe direction;

信号补偿模块，用于根据所述自适应权矢量对所述回波信号进行补偿。A signal compensation module, configured to compensate the echo signal according to the adaptive weight vector.

本发明的基于导数更新的双基机载雷达杂波补偿装置，在双基条件下实现基于导数更新的处理，利用该方法对回波数据进行补偿后，能够有效降低双基机载雷达的距离依赖性，进而大大提高空时自适应处理的地面动目标检测性能，极大的提高了雷达检测的工作效率。The bistatic airborne radar clutter compensation device based on derivative update of the present invention realizes the processing based on derivative update under the bistatic condition, and after the echo data is compensated by using this method, the distance of the bistatic airborne radar can be effectively reduced Dependency, and then greatly improve the ground moving target detection performance of space-time adaptive processing, and greatly improve the efficiency of radar detection.

本发明的其它特征和优点将在随后的说明书中阐述，并且，部分地从说明书中变得显而易见，或者通过实施本发明而了解。本发明的目的和其他优点可通过在所写的说明书、权利要求书、以及附图中所特别指出的结构来实现和获得。Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

下面通过附图和实施例，对本发明的技术方案做进一步的详细描述。The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

附图说明Description of drawings

附图用来提供对本发明的进一步理解，并且构成说明书的一部分，与本发明的实施例一起用于解释本发明，并不构成对本发明的限制。在附图中：The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

图1为本发明实施例的方法流程示意图；Fig. 1 is the schematic flow chart of the method of the embodiment of the present invention;

图2为本发明实施例的装置结构示意图。Fig. 2 is a schematic diagram of the device structure of the embodiment of the present invention.

具体实施方式Detailed ways

下面结合附图，对本发明的具体实施方式进行详细描述，但应当理解本发明的保护范围并不受具体实施方式的限制。The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

如图1所示，该方法包括：As shown in Figure 1, the method includes:

步骤S101：接收双基机载雷达的回波信号，计算所述回波信号第K个待检测距离门的收发距离之和；Step S101: Receive the echo signal of the bistatic airborne radar, and calculate the sum of the sending and receiving distances of the Kth range gate to be detected in the echo signal;

具体的，根据下列公式计算第K个待检测距离门的收发距离之和R_s(k)R：Specifically, the sum R _s(k)R of the sending and receiving distances of the Kth range gate to be detected is calculated according to the following formula:

${R R}_{s the s ((k k)) R R} = = {R R}_{s the s ((k k))} - - \sqrt{{L L}^{22} + + 22 {H h}_{R R} {H h}_{T T} - - 22 {H h}_{R R}^{22} + + {R R}_{s the s ((k k)) R R}^{22} - - 22 \sqrt{{L L}^{22} - - {(({H h}_{R R} - - {H h}_{H h}))}^{22}} \sqrt{{R R}_{s the s ((k k)) R R}^{22} - - {H h}_{R R}^{22}} cos cos (({σ σ}_{R R} - - \frac{π π}{22}))},,$

L为发射载机和接收载机之间的距离，R_s(k)为第K个待检测距离门的距离，H_R为接收载机的飞行高度，H_T为发射载机的飞行高度，H_H为检测点的高度，σ_R为接收载机速度方向与两机之间连线的水平偏角；L is the distance between the transmitting carrier and the receiving carrier, R _s(k) is the distance of the Kth distance gate to be detected, _HR is the flying height of the receiving carrier, H _T is the flying height of the transmitting carrier, H _H is the height of the detection point, σ _R is the horizontal deflection angle between the speed direction of the receiving aircraft and the line connecting the two aircraft;

对上式进行简化得到：Simplify the above formula to get:

$\begin{matrix} {(({(({R R}_{s the s ((k k))} - - {R R}_{s the s ((k k)) R R}))}^{22} - - (({L L}^{22} + + 22 {H h}_{R R} {H h}_{T T} - - 22 {H h}_{R R}^{22} + + {R R}_{s the s ((k k)) R R}^{22}))))}^{22} = = \\ 44 (({L L}^{22} - - {(({H h}_{R R} - - {H h}_{T T}))}^{22})) (({R R}_{s the s ((k k)) R R}^{22} - - {H h}_{R R}^{22})) {sin sin}^{22} {σ σ}_{R R} \end{matrix}$

对上述方程进行求解，得到：Solving the above equations, we get:

${R R}_{s the s ((k k)) R R} = = \frac{44 (({R R}_{s the s ((k k))}^{22} - - A A)) {R R}_{s the s ((k k))} + + \sqrt{{((44 (({R R}_{s the s ((k k))}^{22} - - A A)) {R R}_{s the s ((k k))}))}^{22} - - 44 (({44 R R}_{s the s ((k k))}^{22} - - 44 B B {sin sin}^{22} {σ σ}_{R R})) (({(({R R}^{22} - - A A))}^{22} + + 44 B B {H h}_{R R}^{22} {sin sin}^{22} {σ σ}_{R R}))}}{22 ((44 {R R}_{s the s ((k k))}^{22} - - 44 B B {sin sin}^{22} {σ σ}_{R R}))}$

其中，B＝L²-(H_R-H_T)²。in, B = L ² -(H _R _-HT ) ² .

步骤S102：根据所述第K个待检测距离门的收发距离之和，计算主瓣方向的接收俯仰角余弦；Step S102: Calculate the cosine of the receiving pitch angle in the direction of the main lobe according to the sum of the transmitting and receiving distances of the Kth range gate to be detected;

具体的，根据下列公式计算主瓣方向的接收俯仰角余弦 Specifically, the cosine of the receiving pitch angle in the direction of the main lobe is calculated according to the following formula

步骤S103：根据主瓣方向的接收距离或俯仰角，计算导数更新的自适应权矢量；Step S103: Calculate the adaptive weight vector for derivative update according to the receiving distance or pitch angle in the direction of the main lobe;

步骤S104：根据所述自适应权矢量对所述回波信号进行补偿。Step S104: Compensate the echo signal according to the adaptive weight vector.

步骤S105：对所述补偿后的回波信号进行全维STAP处理，并对处理后的回波信号进行动目标检测。Step S105: Perform full-dimensional STAP processing on the compensated echo signal, and perform moving target detection on the processed echo signal.

本发明的基于导数更新的双基机载雷达杂波补偿方法，在双基条件下实现基于导数更新的处理，利用该方法对回波数据进行补偿后，能够有效降低双基机载雷达的距离依赖性，进而大大提高空时自适应处理的地面动目标检测性能，极大的提高了雷达检测的工作效率。The bistatic airborne radar clutter compensation method based on the derivative update of the present invention realizes the processing based on the derivative update under the bistatic condition, and after the echo data is compensated by using the method, the distance of the bistatic airborne radar can be effectively reduced Dependence, and then greatly improve the ground moving target detection performance of space-time adaptive processing, and greatly improve the efficiency of radar detection.

如图2所示，该装置包括：As shown in Figure 2, the device includes:

第一计算模块10，用于接收双基机载雷达的回波信号，计算所述回波信号第K个待检测距离门的收发距离之和；The first calculation module 10 is used to receive the echo signal of the bistatic airborne radar, and calculate the sum of the sending and receiving distances of the Kth range gate to be detected of the echo signal;

第二计算模块20，用于根据所述第K个待检测距离门的收发距离之和，计算主瓣方向的接收俯仰角余弦；The second calculation module 20 is used to calculate the receiving pitch angle cosine of the main lobe direction according to the sum of the transmitting and receiving distances of the Kth range gate to be detected;

第三计算模块30，用于根据主瓣方向的接收距离或俯仰角，计算导数更新的自适应权矢量；The third calculation module 30 is used to calculate the adaptive weight vector of derivative update according to the receiving distance or pitch angle of the main lobe direction;

信号补偿模块40，用于根据所述自适应权矢量对所述回波信号进行补偿。The signal compensation module 40 is configured to compensate the echo signal according to the adaptive weight vector.

信号检测模块50，用于对所述补偿后的回波信号进行全维STAP处理，并对处理后的回波信号进行动目标检测。The signal detection module 50 is configured to perform full-dimensional STAP processing on the compensated echo signal, and perform moving target detection on the processed echo signal.

在上述技术方案中，所述第一计算模块10具体用于：In the above technical solution, the first calculation module 10 is specifically used for:

根据下列公式计算第K个待检测距离门的收发距离之和R_s(k)R：Calculate the sum R _s(k)R of the receiving and sending distances of the Kth range gate to be detected according to the following formula:

对上式进行简化得到：Simplify the above formula to get:

对上述方程进行求解，得到：Solving the above equations, we get:

其中，B＝L²-(H_R-H_T)²。in, B = L ² -(H _R _-HT ) ² .

所述第二计算模块20具体用于The second calculation module 20 is specifically used for

根据下列公式计算主瓣方向的接收俯仰角余弦 Calculate the cosine of the receiving pitch angle in the direction of the main lobe according to the following formula

本发明的基于导数更新的双基机载雷达杂波补偿装置，在双基条件下实现基于导数更新的处理，利用该方法对回波数据进行补偿后，能够有效降低双基机载雷达的距离依赖性，进而大大提高空时自适应处理的地面动目标检测性能，极大的提高了雷达检测的工作效率。The bistatic airborne radar clutter compensation device based on derivative update of the present invention realizes the processing based on derivative update under the bistatic condition, and after the echo data is compensated by using this method, the distance of the bistatic airborne radar can be effectively reduced Dependence, and then greatly improve the ground moving target detection performance of space-time adaptive processing, and greatly improve the efficiency of radar detection.

以下对本发明的技术方案作详细说明：The technical scheme of the present invention is described in detail below:

DBU(基于导数更新)方法DBU (Derivative Based Update) method

DBU最初用来解决机载前视阵雷达的杂波距离依赖性问题，它认为杂波的分布特性是斜距R的函数，且随着斜距的变化而变化，则相应的STAP权矢量也应该是斜距的函数。设参考距离门为r_m，相应的STAP权矢量为W_DBU(r_m)，则第r_i个距离门对应的权矢量W_DBU(r_i)的泰勒展开式为:DBU was originally used to solve the problem of distance dependence of clutter in airborne forward-looking array radar. It believed that the distribution characteristics of clutter were a function of the slope distance R, and as the slope distance changed, the corresponding STAP weight vector also Should be a function of slope distance. Suppose the reference range gate is r _m , and the corresponding STAP weight vector is W _DBU (r _m ), then the Taylor expansion of the weight vector W _DBU (r _i ) corresponding to the r _i- th range gate is:

${W W}_{DBU DBU} (({r r}_{i i})) = = {W W}_{DBU DBU} (({r r}_{m m})) + + (({r r}_{i i} - - {r r}_{m m})) {W W}_{DBU DBU} {(({r r}_{m m}))}^{' '} + + \frac{11}{22} {(({r r}_{i i} - - {r r}_{m m}))}^{22} {W W}_{DBU DBU} {(({r r}_{m m}))}^{' '' '} + + . . . . . . ((11))$

若认为r_i-r_m很小(相对于r_m归一化后)，忽略公式(1)中二次项以及其以上高次项的影响，则：If it is considered that r _i -r _m is small (after normalization relative to r _m ), ignoring the influence of the quadratic term in formula (1) and its higher-order terms, then:

W_DBU(r_i)≈W_DBU(r_m)+(r_i-r_m)W_DBU(r_m)' (2)W _DBU (r _i )≈W _DBU (r _m )+(r _i -r _m )W _DBU (r _m )' (2)

W_DBU(r_m)',W_DBU(r_m)″,分别表示W_DBU(r_m)的一阶与二阶导数。用目标距离门俯仰角余弦来代替斜距作为更新变量的DBU方法，处理原理与传统DBU方法相同。由上面的表达式可知对于不同的距离门，其自适应权矢量是不同的，然而在实际工程实现时通常用雷达接收的所有距离门中的一段或全程距离门数据来统计平均估计杂波协方差矩阵，并用由此计算得到的STAP权矢量对正在处理的一段或全程距离门数据进行杂波抑制，即对于正在处理的一段或全程距离门数据来说，所有距离门的最优权矢量应该相同。W _DBU (r _m )', W _DBU (r _m )″, represent the first-order and second-order derivatives of W _DBU (r _m ) respectively. The DBU method uses the cosine of the pitch angle of the target range gate to replace the slope distance as the update variable, The processing principle is the same as the traditional DBU method. It can be seen from the above expression that for different range gates, the adaptive weight vectors are different, but in actual engineering implementation, a section or the whole range gate of all range gates received by radar is usually used data to statistically estimate the average clutter covariance matrix, and use the calculated STAP weight vector to perform clutter suppression on the one-segment or the whole range gate data being processed, that is, for the one-segment or the whole range gate data being processed, all The optimal weight vectors for the range gates should be the same.

由上面的权矢量处理相应距离门的NK×1(N为天线数，K时域脉冲数)维数据X(r_i)后的相应输出为：The corresponding output after processing the NK×1 (N is the number of antennas, K the number of time-domain pulses) dimensional data X(r _i ) of the corresponding range gate by the above weight vector is:

$\begin{matrix} Y Y {(({r r}_{i i}))}_{DBU DBU} = = {W W}_{DBU DBU} {(({r r}_{m m}))}^{H h} X x (({r r}_{i i})) + + (({r r}_{i i} - - {r r}_{m m})) {W W}_{DBU DBU} {(({r r}_{m m}))}^{' ' H h} X x (({r r}_{i i})) \\ = = {(\begin{matrix} {W W}_{DBU DBU} (({r r}_{m m})) \\ {W W}_{DBU DBU} {(({r r}_{m m}))}^{' '} \end{matrix})}^{H h} (\begin{matrix} X x (({r r}_{i i})) \\ (({r r}_{i i} - - {r r}_{m m})) X x (({r r}_{i i})) \end{matrix}) = = {W W}_{DBU DBU}^{H h} {X x}_{DBU DBU} (({r r}_{i i})) \end{matrix} - - - - - - ((33))$

这样，经过公式(3)的变换后自适应权矢量就不再随距离门的变化而变化，自适应权随距离变化的那种关系已经被转移到各个单元数据之中，从而实现了对杂波的距离依赖性补偿，此时就可以用统计平均方法来求自适应权矢量，一般情况下取参考距离门为最远端的距离门。In this way, after the transformation of the formula (3), the adaptive weight vector no longer changes with the change of the range gate, and the relationship of the adaptive weight with the distance has been transferred to each unit data, thus realizing the hybrid Wave distance-dependent compensation, at this time, the statistical average method can be used to calculate the adaptive weight vector. Generally, the reference range gate is taken as the farthest range gate.

双基机载雷达DBU方法DBU Method for Bistatic Airborne Radar

由于双基机载雷达的几何结构决定了在一个待检测距离门上各目标散射点与接收机之间的距离和俯仰角是变化的。考虑到双基机载雷达的回波只与接收距离和接收方位角有关，所以我们取接收主瓣方位向的接收距离或俯仰角余弦为更新变量，实现双基机载DBU。因为待检测距离门的接收发射距离之和与相邻距离门之间的差别是固定值，而当只取接收距离为DBU更新变量时，发射距离的变化承担了原来固定距离变化量中的一部分，所以接收距离的变化量要小于原来接收发射距离之和的变化量。从公式(1)中我们发现相邻更新变量之间变化量越小，舍掉的二阶以上的信息越少，则其所得到的处理结果越接近于最优处理。Due to the geometric structure of the bistatic airborne radar, the distance and elevation angle between each target scattering point and the receiver on a range gate to be detected are changed. Considering that the echo of the bistatic airborne radar is only related to the receiving distance and receiving azimuth, we take the receiving distance or the cosine of the elevation angle of the main lobe as the update variable to realize the bistatic airborne DBU. Because the difference between the sum of the receiving and transmitting distances of the range gate to be detected and the adjacent range gates is a fixed value, and when only the receiving distance is taken as the DBU update variable, the change of the transmitting distance bears a part of the original fixed distance change , so the variation of the receiving distance is smaller than the variation of the sum of the original receiving and transmitting distances. From the formula (1), we find that the smaller the variation between adjacent update variables and the less information above the second order discarded, the closer the obtained processing result is to the optimal processing.

若第k个待检测距离门的距离为R_S(k)(接收发射距离之和)已知，可以得到关于接收方向图主瓣方向(接收阵面法线方向)的接收距离方程为If the distance of the kth range gate to be detected is known as R _S(k) (the sum of receiving and transmitting distances), the receiving distance equation about the main lobe direction of the receiving pattern (the normal direction of the receiving front) can be obtained as

${R R}_{s the s ((k k)) R R} = = {R R}_{s the s ((k k))} - - \sqrt{{L L}^{22} + + 22 {H h}_{R R} {H h}_{T T} - - 22 {H h}_{R R}^{22} + + {R R}_{s the s ((k k)) R R}^{22} - - 22 \sqrt{{L L}^{22} - - {(({H h}_{R R} - - {H h}_{H h}))}^{22}} \sqrt{{R R}_{s the s ((k k)) R R}^{22} - - {H h}_{R R}^{22}} cos cos (({σ σ}_{R R} - - \frac{π π}{22}))} - - - - - - ((44))$

对上式进行化简，得：Simplifying the above formula, we get:

$\begin{matrix} {(({(({R R}_{s the s ((k k))} - - {R R}_{s the s ((k k)) R R}))}^{22} - - (({L L}^{22} + + 22 {H h}_{R R} {H h}_{T T} - - 22 {H h}_{R R}^{22} + + {R R}_{s the s ((k k)) R R}^{22}))))}^{22} = = \\ 44 (({L L}^{22} - - {(({H h}_{R R} - - {H h}_{T T}))}^{22})) (({R R}_{s the s ((k k)) R R}^{22} - - {H h}_{R R}^{22})) {sin sin}^{22} {σ σ}_{R R} \end{matrix} - - - - - - ((55))$

可以看到，上式是一个关于收发距离之和R_s(k)R的方程，对该方程求解。得到R_s(k)R的数学表达式为：It can be seen that the above formula is an equation about the sum of sending and receiving distances R _s(k)R , and the equation is solved. The mathematical expression to get R _s(k)R is:

${R R}_{s the s ((k k)) R R} = = \frac{44 (({R R}_{s the s ((k k))}^{22} - - A A)) {R R}_{s the s ((k k))} + + \sqrt{{((44 (({R R}_{s the s ((k k))}^{22} - - A A)) {R R}_{s the s ((k k))}))}^{22} - - 44 (({44 R R}_{s the s ((k k))}^{22} - - 44 B B {sin sin}^{22} {σ σ}_{R R})) (({(({R R}^{22} - - A A))}^{22} + + 44 B B {H h}_{R R}^{22} {sin sin}^{22} {σ σ}_{R R}))}}{22 ((44 {R R}_{s the s ((k k))}^{22} - - 44 B B {sin sin}^{22} {σ σ}_{R R}))} - - - - - - ((66))$

$A A = = {L L}^{22} + + 22 {H h}_{R R} {H h}_{T T} - - 22 {H h}_{R R}^{22} - - - - - - ((77))$

B＝L²-(H_R-H_T)² (8)B＝L ² -(H _R -H _T ) ² (8)

因为本发明的双基载机构型为收在后、发在前，且阵面的方位角为逆时针方向，所以公式(6)中的平方根值取正。Because the configuration of the dual-base carrier of the present invention is retracted at the back and launched at the front, and the azimuth of the front is counterclockwise, the square root value in the formula (6) is positive.

进而可以得到关于接收机主瓣方向(沿阵面法线方向)的接收俯仰角余弦：Furthermore, the cosine of the receiving pitch angle with respect to the main lobe direction of the receiver (along the front normal direction) can be obtained:

为了方便区分，把以接收机主瓣方向接收距离为更新变量的方法称为DBU，把以接收机主瓣方向俯仰角余弦为更新变量的方法称为EDBU。由于两种方法处理过程基本一致，这里只说明以接收距离为更新变量的DBU算法过程。In order to facilitate the distinction, the method of taking the receiving distance in the direction of the main lobe of the receiver as the update variable is called DBU, and the method of taking the cosine of the elevation angle of the main lobe of the receiver as the update variable is called EDBU. Since the processing processes of the two methods are basically the same, only the DBU algorithm process with the receiving distance as the update variable is described here.

对接收的P个距离门的回波数据DBU补偿后进行杂波协方差矩阵估计可得：Estimate the clutter covariance matrix after DBU compensation of the received echo data of P range gates:

${R R}_{DBU DBU} = = \frac{11}{P P} {Σ Σ}_{i i = = 11}^{P P} {X x}_{DBU DBU} (({r r}_{i i})) {X x}_{DBU DBU} {(({r r}_{i i}))}^{H h} - - - - - - ((1010))$

其中：in:

${X x}_{DBU DBU} (({r r}_{i i})) = = (\begin{matrix} X x (({r r}_{i i})) \\ {γ γ}_{DBU DBU} (({r r}_{ri the ri} - - {r r}_{rm rm})) X x (({r r}_{i i})) \end{matrix}) - - - - - - ((1111))$

$\frac{11}{P P} {Σ Σ}_{i i = = 11}^{P P} {γ γ}_{DBU DBU}^{22} {(({r r}_{ri the ri} - - {r r}_{rm rm}))}^{22} = = 11 - - - - - - ((1212))$

上面公式(8)中的γ_DBU为当X_DBU(r_i)为高斯白噪声时保证R_DBU为单位矩阵的归一化系数。r_ri为第i个距离门的接收斜距，r_rm为参考距离门的接收斜距，通常选取为最远端的距离门。γ _DBU in the above formula (8) is a normalization coefficient to ensure that R _DBU is an identity matrix when X _DBU (r _i ) is Gaussian white noise. r _ri is the receiving slant distance of the i-th range gate, and r _rm is the receiving slant distance of the reference range gate, which is usually selected as the farthest range gate.

DBU方法对应的协方差矩阵是2NK维的，而直接对回波数据进行SMI算法即直接STAP处理对应是数据协方差矩阵是NK维的，对NK维的杂波协方差矩阵进行估计和求逆，其运算量为o(NK)³，所以DBU方法对应的计算量要比直接STAP处理大，并且由于增加了协方差矩阵的维数，致使对i iD(独立同分布)样本的需求也会变大，这也是DBU方法需要改进的问题，有待进一步研究。The covariance matrix corresponding to the DBU method is 2NK-dimensional, and the SMI algorithm is directly performed on the echo data, that is, the direct STAP processing corresponds to the data covariance matrix being NK-dimensional, and the NK-dimensional clutter covariance matrix is estimated and inverted , and its calculation amount is o(NK) ³ , so the calculation amount corresponding to the DBU method is larger than that of the direct STAP processing, and due to the increase in the dimension of the covariance matrix, the demand for i iD (independent and identically distributed) samples will also increase becomes larger, this is also a problem that the DBU method needs to improve, and needs further research.

DBU方法自适应权矢量的计算由下面准则求出：The calculation of the adaptive weight vector of the DBU method is obtained by the following criteria:

$\{\begin{matrix} min min {W W}_{DBU DBU}^{H h} {R R}_{DBU DBU} {W W}_{SBU SBUs} \\ st st . . {W W}_{DBU DBU}^{H h} S S = = 11 \end{matrix} - - - - - - ((1313))$

${W W}_{DBU DBU} = = {R R}_{DBU DBU}^{- - 11} S S / / (({S S}^{H h} {R R}_{DBU DBU}^{- - 11} S S)) - - - - - - ((1414))$

$S S = = (\begin{matrix} {S S}_{T T} (({f f}_{d d 00})) &CircleTimes; &CircleTimes; {S S}_{S S} (({ψ ψ}_{S S 00})) \\ 00_{NK NK \times \times 11} \end{matrix}) - - - - - - ((1515))$

公式(16)中d为阵元间距，λ为波长，cosψ_S0为接收空域锥角余弦。公式(17)中f_d0为待检测的多普勒通道频率，f_r为脉冲重复频率，为Kronecker直积。对某个多普勒通道的改善因子由下面公式求出：In formula (16) d is the array element spacing, λ is the wavelength, and cosψ _S0 is the cosine of the receiving airspace cone angle. In formula (17) f _d0 is the Doppler channel frequency to be detected, f _r is the pulse repetition frequency, is the Kronecker direct product. The improvement factor for a certain Doppler channel is obtained by the following formula:

$IF IF (({f f}_{d d 00})) = = \frac{{| | {W W}_{DBU DBU}^{H h} | |}^{22} ((CNR CNR + + 11)) {σ σ}^{22}}{{W W}_{DBU DBU}^{H h} {R R}_{DBU DBU} {W W}_{DBU DBU}} - - - - - - ((1818))$

CNR为输入的杂噪比，σ²为噪声功率，在这里使用的是全维最优STAP算法，在此不再对降维STAP算法进行赘述。CNR is the noise-to-noise ratio of the input, and σ ² is the noise power. The full-dimensional optimal STAP algorithm is used here, and the dimensionality reduction STAP algorithm will not be described here.

本发明能有多种不同形式的具体实施方式，上面以图-图2为例结合附图对本发明的技术方案作举例说明，这并不意味着本发明所应用的具体实例只能局限在特定的流程或实施例结构中，本领域的普通技术人员应当了解，上文所提供的具体实施方案只是多种优选用法中的一些示例，任何体现本发明权利要求的实施方式均应在本发明技术方案所要求保护的范围之内。The present invention can have a variety of specific implementations in different forms. The technical solutions of the present invention are illustrated with reference to the accompanying drawings above, which does not mean that the specific examples used by the present invention can only be limited to specific examples. In the process flow or example structure, those of ordinary skill in the art should understand that the specific implementations provided above are only some examples of various preferred usages, and any implementation that embodies the claims of the present invention shall be within the technical scope of the present invention. within the scope of protection required by the program.

最后应说明的是：以上所述仅为本发明的优选实施例而已，并不用于限制本发明，尽管参照前述实施例对本发明进行了详细的说明，对于本领域的技术人员来说，其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still The technical solutions recorded in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A double-base airborne radar clutter compensation method based on derivative updating is characterized by comprising the following steps:

receiving echo signals of the double-base airborne radar, and calculating the sum of the receiving and sending distances of the Kth range gate to be detected of the echo signals;

calculating the cosine of the receiving pitch angle in the main lobe direction according to the sum of the receiving and transmitting distances of the Kth distance gate to be detected;

calculating a self-adaptive weight vector updated by a derivative according to the receiving distance or the pitch angle in the main lobe direction;

and compensating the echo signal according to the self-adaptive weight vector.

2. The method for derivative update based bistatic airborne radar clutter compensation according to claim 1, further comprising:

and carrying out full-dimensional STAP processing on the compensated echo signal, and carrying out moving target detection on the processed echo signal.

3. The method for compensating clutter according to claim 1, wherein the step of calculating the sum of the transmit-receive distances of the kth range gate to be detected of the echo signal specifically comprises:

calculating the sum R of the receiving and transmitting distances of the Kth distance door to be detected according to the following formula_s(k)R：

L is the distance between the transmitting and receiving carriers, R_s(k)For the Kth distance to be detected from the door, H_RTo receive the flying height of the carrier, H_TTo transmit the flying height of the carrier, H_HFor height of detection point, σ_RThe horizontal deflection angle of a connecting line between the speed direction of the receiving carrier and the two machines;

simplifying the above equation yields:

solving the above equation to obtain:

wherein,B＝L²-(H_R-H_T)²。

4. the method for double-base airborne radar clutter compensation based on derivative update of claim 1, wherein the step of calculating the cosine of the received pitch angle in the mainlobe direction specifically comprises:

calculating the cosine of the received pitch angle in the main lobe direction according to the following formula

5. A double-base airborne radar clutter compensation device based on derivative updating is characterized by comprising:

the first calculation module is used for receiving echo signals of the double-base airborne radar and calculating the sum of the receiving and transmitting distances of the Kth range gate to be detected of the echo signals;

the second calculation module is used for calculating the cosine of the receiving pitch angle in the main lobe direction according to the sum of the receiving and sending distances of the Kth distance gate to be detected;

the third calculation module is used for calculating the self-adaptive weight vector updated by the derivative according to the receiving distance or the pitch angle in the main lobe direction;

and the signal compensation module is used for compensating the echo signal according to the self-adaptive weight vector.

6. The derivative update based bistatic airborne radar clutter compensation apparatus of claim 5, further comprising:

and the signal detection module is used for carrying out full-dimensional STAP processing on the compensated echo signal and carrying out moving target detection on the processed echo signal.

7. The derivative update-based bistatic airborne radar clutter compensation apparatus according to claim 5, wherein said first calculation module is specifically configured to:

simplifying the above equation yields:

solving the above equation to obtain:

wherein,B＝L²-(H_R-H_T)²。

8. the derivative update-based bistatic airborne radar clutter compensation apparatus according to claim 5, wherein said second calculation module is specifically configured to