“雷达通信电子战”微信公众号添加字幕 视频来源：MathWorks
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
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,
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,
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.
它被构成一个三维矩阵 It's organized into a three dimensional matrix.
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.
代表每一个单独的雷达脉冲 Representing each individual radar pulse.
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
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.
有时被称为驻留时间 This is sometimes called the dwell Time
在这个部分，我来来讨论三种 In this presentation,We'll talk about the three
信号处理算法: processing algorithm,
从波束形成开始 Starting with beamforming.
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.
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
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
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
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.
第二种算法是匹配滤波或脉冲压缩 The second algorithm is matched Filtering or pulse compression
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
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
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.
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.
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,
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.
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.
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
具有150m/s的径向速度 With a radial velocity of one hundred and fifty metres per second.
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.
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.
他们是复数类型的数据，因为是 It's complex data type because there are complex
阵列后是I/Q采样接收的 I/Q samples that had been received here after the array.
开始进行波束形成 They'll start with beamforming,
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.
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.
一旦我们创建了这个对象 And once we've created this object,
我们可以采样 We can use
这个step函数来进行波束形成 this step method is a way of executing the beamformer.
为了说明这一点 For illustration
目地是把这两个波束指向0度 Purposes were going to steer the beam both to zero degrees
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.
在仿真结果图上 On the resulting plot,
我们可以看到三种不同的东西 We can see three different things.
首先是点响应 The first is the plot response.
这是均匀线性阵列的响应 This is the response of the uniform linear array object.
我们可以看到没有波束形成 We can see with no beam forming
响应的峰值是在0度的位置 the peak of the response is at zero degrees as myth.
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.
如果我们只是将阵元接收的信号相加 So if we just sum the receive elements,
我们看不到目标的任何迹象 We can't see any indication of the target's president.
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.
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
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.
现在 Now
当你处理雷达数据立方体时 When you're processing the radar data cube,
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.
这就是你在这里看到的过程 And that's the processing you see here.
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.
我们现在可以使用脉冲压缩来确定目标的距离 We can now use pulse compression to determine the distance of the target.
这里我们可以使用get match filter方法返回发送波形的匹配滤波器 And you'll see here we can use the get match filter method to return the matched filter for the transmit waveform,
利用这个滤波对象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.
你可以在这里看到 You can see here.
结果是在运动物体的距离仓处出现一个尖峰 The result is a sharp peak at the range bin of the moving object.
这是使用调制脉冲的优点之一 就像我们在左边看到的线性调频波形 This is one of the advantages of using a modulated pulse like the linear FM wave form we see here on the left.
有一个非常强的相关性 因此产生一个强大的航空窥视目标 There is a very strong correlation property and therefore produces a strong aero peek at the target.
返回 Return.
一旦我们发现了这个峰值 And once we've detected this peak,
我们可以计算出运动物体的距离 We can calculate the distance of the moving object.
存在峰值的时间样本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.
在这种情况下 In this case,
我们必须使用time to range函数并减去匹配过滤器的长度以将时间转换为距离 We have to use the time to range function and subtract the length of the match filter to convert the time to distance.
当我们执行时 When we execute this,
它给了我们九千的距离 It gives us a distance of nine thousand,
九百九十四公里 Nine hundred and ninety four kilometers,
在我们选择的波形范围内 Which is within the range resolution of the wave form that we selected.
最后 At last of all,
我们可以确定目标的速度 We can determine the speed of the target,
利用在目标回波中观测到的多普勒频移 Using the Doppler shift observed in the target returns.
在这种情况下 In this case,
F T穿过垃圾箱 The F of T across the range bin,
在检测到移动物体的地方 我们可以在这里看到峰值 Where the moving objects has been detected yields a plot where we can see the peak here.
频率是140赫兹 And it's at a frequency of one hundred and forty hertz,
与无线电哲学相对应 Which corresponds to a radio philosophy.
每秒一百十五米 One hundred and fifteen meters per second.
现在这个多普勒分辨率是停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.
所以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,
我们可以在这个特殊的物体上发出更多的脉冲 We can send out more pulses at this particular object.
相位种族主义工具箱还设置了多普勒响应系统 A phase racism toolbox also has arranged Doppler response system,
反对 Object.
这个对象本质上计算数据立方体中跨范围引脚的fft This object essentially computes the fft across the range pins in the data cube.
所以当你看这个情节的时候 So when you look at this plot,
在20公里的距离和150米每秒的速度下 你可以看到强劲的返回 You can see the strong return at a distance of twenty kilometers and at a speed of one hundred fifty meters per second.
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.
face种族主义工具箱有其他非常处理技术 如DNA算法和员工时空 The face racism toolbox has other very processing techniques like DNA algorithms and staff space time,
自适应处理 Adaptive processing,
您可以从中提取有关存档中包含的目标返回的更多信息 Where you can extract even more information about the target returns contained in the archive.