1 00:00:00,930 --> 00:00:01,710 “雷达通信电子战”微信公众号添加字幕 视频来源：MathWorks 2 00:00:01,711 --> 00:00:05,790 大家好，我叫Rick Gentile，是相控阵系统工具箱的产品经理 Hi，My name is Rick Gentile on the phased array system Toolbox product manager 3 00:00:05,791 --> 00:00:11,250 我想向您展示，使用Matlab在相控阵系统工具箱处理雷达数据立方体是多么容易 I'd like to show you how easy it is to process or rate our data cube with MatLab in the phase array system toolbox, 4 00:00:11,251 --> 00:00:13,050 正如我们第一部分的视频中所看到的 As we saw in part one of the recording, 6 00:00:13,081 --> 00:00:17,730 雷达数据立方体是相控阵雷达接收到的雷达回波 The radar Data Cube is a collection of radar returns received by a phased array radar. 7 00:00:17,731 --> 00:00:20,400 它被构成一个三维矩阵 It's organized into a three dimensional matrix. 8 00:00:20,401 --> 00:00:23,850 矩阵的纵轴是由接收到的快时间采样点组成 The vertical axis of the queue is composed of the received time samples. 9 00:00:23,851 --> 00:00:26,280 代表每一个单独的雷达脉冲 Representing each individual radar pulse. 10 00:00:26,281 --> 00:00:31,010 横轴表示在阵列的每个阵元处收集的采样点 The horizontal axis contains the time samples collected at each of the array elements 11 00:00:31,011 --> 00:00:36,630 对于深度轴，表示有一串连续的脉冲照射在特定方向或物体上 For the depth axis，there's a collection of consecutive pulses focus on particular direction or object. 12 00:00:36,631 --> 00:00:38,780 有时被称为驻留时间 This is sometimes called the dwell Time 13 00:00:38,981 --> 00:00:41,250 在这个部分，我来来讨论三种 In this presentation,We'll talk about the three 14 00:00:41,251 --> 00:00:42,570 信号处理算法: processing algorithm, 15 00:00:42,571 --> 00:00:44,350 从波束形成开始 Starting with beamforming. 16 00:00:44,351 --> 00:00:50,460 波束形成是将各个接收通道的信号组合成单个接收通道信号的过程 A Beamforming is a process of combining the individual receive channels into a single received signal. 17 00:00:50,461 --> 00:00:55,430 你可以把波束形成看作是一个空间滤波器，对通道应用了不同的复数权系数 You can think of beam forming as a spatial filter that applies different Complex weights of the channels 19 00:00:55,471 --> 00:00:59,820 而其中的一些结果可以有效地使波束指向特定的方向 And that some of the results to effectively steer a beam in a specific direction 20 00:00:59,821 --> 00:01:03,330 波束形成应用于雷达数据立方体的横轴上 A beam forming works across the horizontal axis of the radar data cube 21 00:01:03,331 --> 00:01:06,930 它可提供有关你要跟踪的目标的方位信息 And it gives you information about the bearing elevation of the object you're trying to track. 22 00:01:07,980 --> 00:01:11,660 第二种算法是匹配滤波或脉冲压缩 The second algorithm is matched Filtering or pulse compression 24 00:01:11,701 --> 00:01:16,980 它通过将接收信号与原样本信号的相关来增强雷达回波 Which enhances the radar return by correlating the receive time samples with a sample the version of the source waveform 25 00:01:16,981 --> 00:01:23,100 对构成雷达数据立方体的纵轴数据进行匹配滤波 Matched filtering is performed on the data that makes up the vertical axis of the radar data cube 26 00:01:23,101 --> 00:01:28,420 幅度出现峰值的距离单元可用于确定你要跟踪目标的距离。 The range bit were the peak amplitude occurs can be used to determine the distance of an object you are trying to track. 29 00:01:29,880 --> 00:01:35,700 运动目标的雷达回波的多普勒频移与目标径向速度成比例 The radar returns for moving objects will have a Doppler shift that's proportional to the radial velocity of the object. 30 00:01:35,701 --> 00:01:40,350 因此，如果我们对雷达回波在数据立方体的深度维上做fft So if we take the fft of the radar returns along a depth dimension of the radar data cube, 31 00:01:40,351 --> 00:01:43,140 我们可以得到运动物体的速度信息 We can extract information about the speed of the moving object. 32 00:01:44,790 --> 00:01:48,900 现在让我们看看可以用来处理雷达数据立方体的Matlab代码 Now let's take a look at some Matlab code that can be used to process the radar data cube. 33 00:01:51,690 --> 00:02:01,200 我们将使用之前“建立雷达数据立方体”中的一些代码 为距离雷达20km处的目标快速生成雷达数据 We'll use some code from a previous recording called “building the radar Data Cube” to quickly generate our radar data queue for a target located at 20km away from the radar 34 00:02:01,201 --> 00:02:03,630 具有150m/s的径向速度 With a radial velocity of one hundred and fifty metres per second. 35 00:02:04,590 --> 00:02:07,800 你可以在我的matlab工作空间中看到数据立方体的变量 So you can see the data cube variable in my matlab work space. 36 00:02:07,801 --> 00:02:13,740 每个脉冲采样1000个点，8个接收阵元，32个脉冲 It's built up as a thousand times sample by eight receive element by thirty two pulse variable. 37 00:02:13,741 --> 00:02:15,870 他们是复数类型的数据，因为是 It's complex data type because there are complex 38 00:02:15,871 --> 00:02:19,380 阵列后是I/Q采样接收的 I/Q samples that had been received here after the array. 39 00:02:20,760 --> 00:02:21,900 开始进行波束形成 They'll start with beamforming, 40 00:02:21,901 --> 00:02:25,380 它可提供给我们关于跟踪目标的方位信息 Which can give us information about the bearing of the moving object we are tracking. 41 00:02:26,370 --> 00:02:32,460 你可以使用工具箱中，创建相移波束形成器，并设置我们要使用的属性 You can use the phase races from toolbox to create a phase shift beamformer and set the properties that we would like to use. 42 00:02:34,440 --> 00:02:35,910 一旦我们创建了这个对象 And once we've created this object, 43 00:02:35,911 --> 00:02:36,690 我们可以采样 We can use 44 00:02:36,691 --> 00:02:39,300 这个step函数来进行波束形成 this step method is a way of executing the beamformer. 45 00:02:40,830 --> 00:02:41,460 为了说明这一点 For illustration 46 00:02:41,461 --> 00:02:43,980 目地是把这两个波束指向0度 Purposes were going to steer the beam both to zero degrees 47 00:02:43,981 --> 00:02:50,440 和30度，运动物体的实际位置，通过改变这里来设置 and to a thirty degree where the moving object is actually located So go ahead and execute this cell. 49 00:02:53,280 --> 00:02:54,180 在仿真结果图上 On the resulting plot, 50 00:02:54,181 --> 00:02:56,070 我们可以看到三种不同的东西 We can see three different things. 51 00:02:56,071 --> 00:02:57,750 首先是点响应 The first is the plot response. 52 00:02:58,740 --> 00:03:01,290 这是均匀线性阵列的响应 This is the response of the uniform linear array object. 53 00:03:02,190 --> 00:03:03,090 我们可以看到没有波束形成 We can see with no beam forming 54 00:03:03,091 --> 00:03:06,000 响应的峰值是在0度的位置 the peak of the response is at zero degrees as myth. 55 00:03:06,870 --> 00:03:09,510 在30度的地方有一个凹陷，也就是我们设置的目标位置 It was a deep nel at thirty degrees where our targets located. 56 00:03:10,710 --> 00:03:12,240 如果我们只是将阵元接收的信号相加 So if we just sum the receive elements, 57 00:03:12,241 --> 00:03:15,210 我们看不到目标的任何迹象 We can't see any indication of the target's president. 58 00:03:15,211 --> 00:03:20,370 这是因为我们已经把波束指向了0度的位置 This is because we have the beam steered to the zero degree location. 59 00:03:20,371 --> 00:03:26,210 如果我们在波束形成器中采用相位加权，让阵列指向30度，也就是目标所在的位置 If we use some phase weight in the beam former to steer the array to a thirty degree Where the target is 63 00:03:26,401 --> 00:03:30,450 我们现在看到一个增强的目标回波，从而可以在噪声中看见目标 We now see an enhance target return where we can really see the target return for the noise. 64 00:03:32,280 --> 00:03:32,640 现在 Now 65 00:03:32,641 --> 00:03:34,230 当你处理雷达数据立方体时 When you're processing the radar data cube, 66 00:03:34,231 --> 00:03:37,320 你必须对深度维的所有脉冲做波束形成 You have to do beamforming for all the pulses along the depth dimension. 67 00:03:38,280 --> 00:03:40,710 这就是你在这里看到的过程 And that's the processing you see here. 68 00:03:40,711 --> 00:03:46,920 我们看到的这个图显示了32个脉冲波束形成后的目标回波 The figure we see shows the improved the target returns for the entire sequence of 32 pulses When we use beam forming. 70 00:03:48,480 --> 00:03:52,230 我们现在可以采用脉冲压缩技术来确定目标的距离 We can now use pulse compression to determine the distance of the target. 71 00:03:53,670 --> 00:04:01,710 你将在这里看到我们可以使用step(Matchedfilter) 的方法产生匹配滤波器 And you'll see here we can use the step(Matchedfilter) method to return the matched filter for the transmit waveform 72 00:04:01,711 --> 00:04:06,420 利用这个滤波器对雷达脉冲回波的时间样本进行处理 And we use this filter object to process the time samples for the radar pulse return. 73 00:04:08,670 --> 00:04:09,390 你可以在这里看到 You can see here. 74 00:04:09,391 --> 00:04:13,110 结果是在运动物体的距离单元处出现一个尖峰 The result is a sharp peak at the range bin of the moving object. 75 00:04:13,111 --> 00:04:17,820 这是使用调制脉冲的优点之一，这里使用的是线性调频波形，如左边的图 This is one of the advantages of using a modulated pulse like the linear FM wave form we see here on the left. 76 00:04:18,960 --> 00:04:23,520 它具有很强的相关特性，因此在目标的位置产生了一个很强的峰值 There is a very strong correlation property and therefore produces a strong aero peek at the target Return. 78 00:04:24,480 --> 00:04:26,010 一旦我们检测到了这个峰值 And once we've detected this peak, 79 00:04:26,011 --> 00:04:28,080 我们可以计算得出运动物体的距离 We can calculate the distance of the moving object. 80 00:04:29,070 --> 00:04:32,730 存在峰值的时间样点的索引告诉我们物体的距离 The index of the time sample where the peak exist tells us the distance of the object. 81 00:04:34,110 --> 00:04:34,590 在这种情况下 In this case 82 00:04:34,591 --> 00:04:40,200 我们必须使用time2range函数并减去匹配滤波器的长度，从而将时间转换为距离 We have to use the time to range function and subtract the length of the match filter to convert the time to distance. 83 00:04:40,201 --> 00:04:47,280 当我们运行后,得到的目标距离范围在19940km内 When we execute this, It gives us 19940km Which is within the range resolution of the wave form that we selected. 87 00:04:48,720 --> 00:04:53,790 最后,我们可以通过目标回波中观测到的多普勒频移来确定目标的速度 At last of all,We can determine the speed of the target,Using the Doppler shift observed in the target returns. 90 00:04:55,080 --> 00:04:55,680 在这种情况下 In this case, 91 00:04:55,681 --> 00:05:03,090 在已检测到运动物体的距离单元上做FFT可以产生一个图，在这里我们可以看到峰值 The FFT across the range bin Where the moving objects has been detected yields a plot where we can see the peak here. 93 00:05:04,320 --> 00:05:06,210 频率是140Hz And it's at a frequency of one hundred and forty hertz 94 00:05:06,211 --> 00:05:07,830 对应150m/s Which corresponds to a radio philosophy One hundred and fiftymeters per second 96 00:05:10,980 --> 00:05:14,730 在这里，多普勒分辨率是关于驻留时间内脉冲数的函数 Now this Doppler resolution is a function of the number of pulses in the dwell time. 97 00:05:14,731 --> 00:05:17,700 因此，如果我们想提高速度测量的准确性 So if we wanted to improve the accuracy of the speed measurement, 98 00:05:17,701 --> 00:05:20,070 我们可以在这个特定的目标上发射更多的脉冲 We can send out more pulses at this particular object. 99 00:05:21,480 --> 00:05:25,140 工具箱还有多普勒响应系统 A phase racism toolbox also has arranged Doppler response system object 101 00:05:26,310 --> 00:05:30,660 可以用来对数据立方体跨距离单元计算FFT This object essentially computes the fft across the range pins in the data cube. 102 00:05:30,661 --> 00:05:31,680 所以，当你看到 So when you look at this plot 103 00:05:31,681 --> 00:05:36,480 在20公里的距离和150m/s的速度下，有很强的目标回波 You can see the strong return at a distance of twenty kilometers and at a speed of one hundred fifty meters per second. 104 00:05:37,950 --> 00:05:44,190 本例旨在说明如何处理雷达数据立方体，以确定移动物体的距离、速度和方位 This example is meant to show how to process a radar data cube to determine the range speed and bearing of a moving object. 105 00:05:45,540 --> 00:05:52,320 相控阵工具箱还有有其他处理技术，例如自适应处理 The phase racism toolbox has other very processing techniques like algorithms and space time Adaptive processing 107 00:05:53,671 --> 00:05:57,060 视频来源：MathWorks “雷达通信电子战”微信公众号翻译字幕