ASSP-based radar signal processing

This paper proposes the Application Specific Signal Processor(ASSP)-based implementation of the real-time signal processing system in both spatial domain and time domain for a phased-array radar. This paper also proposes the system-on-silicon hardware design of some ASSPs including the adaptive beamformer, FFT appliation specific integrated circuit, clutter map former and update, moving target extractor and video integrator. The advantages of the processing system are compact, efficient, and robust.     

基于DSP的雷达杂波模拟实现

从雷达杂波的分布特性出发,分析了低分辨率雷达杂波的幅度统计特性和功率谱特性,并依据其分布特性对低分辨率雷达杂波模型进行了建立,同时为了降低杂波仿真计算量,采用频率变换法给出了杂波模拟的具体算法及仿真结果。最后结合某型以ADSP-BF533为核心处理芯片的雷达模拟器,进行了相应的软件设计,实现了高斯瑞利谱杂波回波输出。仿真结果表明,杂波模拟实时性较好,能够满足一般MTI、MTD体制雷达的测试和检测需求。     

基于过采样抽取子带处理的宽带雷达杂波抑制

针对宽带雷达目标回波在相参处理时间内存在越距离单元走动的问题,提出了一种基于过采样抽取子带处理的宽带雷达杂波抑制与目标回波相参积累的方法。通过过采样离散傅立叶变换（DFT）调制滤波器组将宽带雷达回波分为若干子带,每个子带内目标回波不存在越距离单元走动,从而可以通过对相参回波序列的加权处理实现杂波抑制和目标回波的相参积累,将各子带的处理结果通过综合滤波器组重构得到相参积累后的目标距离像。由于采用了过采样抽取滤波器组,子带加权处理所产生的剩余混叠失真很小,因此,与传统的基于2维快速傅立叶变换（FFT）的处理方法相比,可以获得更大的信杂比改善因子和更小的重构距离像失真。通过理论分析和仿真实验证明了该方法对宽带雷达杂波抑制和目标回波相参积累的有效性。     

Complex autocorrelation estimators in radar signal processing

Conventional complex estimators and relay estimators (analysed in the real case by Cacopardi) are compared, examining the estimation errors and the computational cost; complex estimators are analysed in order to obtain the optimum implementation of the adaptive radar processors.     

Acoustooptical approaches to radar signal processing

To realize full benefit from a radar, the analyzed echoes must be strong and sharp. Two options are available: Either the transmitted burst must be an intense, short pulse (often not a propitious arrangement) or the onus can be put on the receiver to process the echo into something more than it appears to be. One method for ``upgrading' the received signal beyond a feeble echo from a not-too-powerful transmitted beam is acoustooptical processing, in which the reflected radar beam is converted to an acoustic wave that is used to modulate a light source. Then with the appropriate operation on the modulated light, the radar echo input is correlated against an optical filter. Of the two acoustooptic correlator classes described here, one works well below 150 MHz and the other is appropriate for frequencies above 150 MHz.     

Maximum likelihood methods in radar array signal processing

We consider robust and computationally efficient maximum likelihood algorithms for estimating the parameters of a radar target whose signal is observed by an array of sensors in interference with unknown second-order statistics. Two data models are described: one that uses the target direction of arrival and signal amplitude as parameters and one that is a simpler, unstructured model that uses a generic target “spatial signature”. An extended invariance principle is invoked to show how the less accurate maximum likelihood estimates obtained from the simple model may be refined to achieve asymptotically the performance available using the structured model. The resulting algorithm requires two one-dimensional (1-D) searches rather than a two-dimensional search, as with previous approaches for the structured case. If a uniform linear array is used, only a single 1-D search is needed. A generalized likelihood ratio test for target detection is also derived under the unstructured model. The principal advantage of this approach is that it is computationally simple and robust to errors in the model (calibration) of the array response     

一种雷达信号处理的检测算法

由于在雷达弱小目标的检测和跟踪过程中,目标是典型的弱小目标且回波较弱,常规的检测算法难以奏效。针对此特点提出采用雷达弱小目标先跟踪后检测的方案,通过对雷达弱小目标长时间积累检测问题进行界定,并根据信号的特殊性对雷达弱小目标进行检测。首先通过进行目标预测,并在此基础上对检测出的目标进行目标跟踪。利用目标的运动沿各种可能轨迹积累能量的特征,对各个能量积累值进行检测判断,从而检测出真实目标并提取出目标的运动轨迹。文中首先对动态规划应用于弱小目标检测的算法进行了详细的描述,同时,对动态规划应用于弱小目标方法的性能也做了进一步分析,并对检测概率和虚警概率关系进行了较详细的推导。最后,通过仿真实验和性能分析得出了门限与虚警概率的关系。     

一种雷达信号处理多任务调度算法

雷达信号处理(RSP)系统的实时性一直是系统设计者需要重点考虑的内容之一。为提高雷达系统的实时性,本文提出了一种基于多模式雷达的RSP任务模型,并根据DP-Wrap算法和流水处理的思想提出了一种高效的任务调度算法。研究了在本模型下影响系统最小处理时间的因素,给出了系统最小处理时间的精确表达式,并在此基础上进行数值仿真,给出了根据RSP任务选择处理器个数的依据。     

基于PIC单片机的六挡调控电涡流缓速器的设计

针对国内重卡的制造工艺．设计了一种基于PIC单片机的新型电涡流缓速器。该缓速器分六挡位调控．可很好地实现恒速．现场编程以及声光提示挡位等功能。     

Suboptimal method for time-space signal processing in airborne radar

A new suboptimal method for time-space signal processing in airborne phased array radar is proposed which can significantly reduce the necessary computation compared with other optimal or suboptimal methods. The numerical results obtained from simulation illustrate that this method possesses ideal performance and is a realisable scheme for real-time processing.<>     

Optimum processing for delay-vector estimation in passive signal arrays

For the purpose of localizing a distant noisy target, or, conversely, calibrating a receiving array, the time delays defined by the propagation across the array of the target-generated signal wavefronts are estimated in the presence of sensor-to-sensor-independent array self-noise. The Cramér-Rao matrix bound for the vector delay estimate is derived, and used to show that either properly filtered beamformers or properly filtered systems of multiplier-correlators can be used to provide efficient estimates. The effect of suboptimally filtering the array outputs is discussed.     

基于组件的雷达信号及数据处理仿真方法

不同体制雷达系统的信号及数据处理在共性功能模拟和特性功能刻画之间存在矛盾问题。基于组件化设计思想,将雷达信号处理及数据处理仿真划分为天线模拟、目标回波功率计算、脉冲压缩、参数测量、航迹起始、跟踪滤波、调度策略等28个组件。通过参数选择实现不同体制雷达特性功能模拟组件的设置,并对共性功能组件复用,实现了相控阵、机扫、无源探测等多种雷达体制的功能级仿真。对各组件进行功能测试,验证了组件化设计方法的可行性。     

小波和形态学在雷达平面位置图像杂噪处理中的应用

提出了利用小波来去除雷达平面位置图像（PPI）的散点噪声，然后利用形态学原理构造目标结构元来滤除斑点噪声和杂波，仿真结果表明，应用此方法可以有效去除噪声和检测目标。     

某雷达杂波数据分析及杂波图技术研究

强地物、海浪杂波严重影响目标检测概率。频域杂波抑制手段是雷达信号处理常用的杂波抑制方法。但是,杂波的时空分布特性复杂多变,所以对杂波的幅度、频谱等特性的研究有助于选择合适的杂波抑制方案。结合某雷达实际工程采集数据分析了地杂波和海杂波的时域和频域分布特性,提出了一种基于雷达杂波环境特性自适应选择遗忘因子的杂波图方法,具体分析了该杂波图检测概率。实测数据实验结果证明了该方法的正确性和有效性。     

脉间二相编码雷达信号的二维处理

超视距雷达系统广泛应用于高频返回散射探测领域,而雷达波形设计则是高频超视距雷达的重点研究课题之一.研究了一种高重复频率脉间二相编码脉冲雷达波形,并提出了针对这种雷达波形的二维信号处理方案.仿真结果表明,新方案能有效地抑制距离旁瓣,提高回波信号检测目标的动态范围.     

Automatic signal processing of front monitor radar for tunnelingmachines

It is planned to install a front monitor impulse radar on the surface of the rotating drill of tunneling machines in order to detect obstacles such as casing pipes of vertical borings. The conventional aperture synthesis technique can no more be applied to such cases because the radar image of a pipe does not constitute a hyperbola as is the case for linear scanning radars. We have developed a special purpose signal processing algorithm with the aid of the discrete model fitting method, which can be used for any pattern of scanning. The details of the algorithm are presented together with the results of numerical simulations and test site experiments     

线性调频与相位编码混合雷达信号处理仿真

为了保证雷达系统能够在复杂的电磁环境中有效地工作,雷达信号的选择尤为重要。本文采用线性调频信号与相位编码信号相结合的码内线性调频信号作为雷达信号,针对这个信号进行了整个雷达信号处理的仿真。仿真结果表明,码内线性调频信号具有较好的抗干扰的特性。     

雷达成像信号处理系统的设计和实现

主要针对雷达成像系统经混频后的低频端电路设计进行介绍,系统分信号滤波与放大模块,AD转换模块,单片机控制模块,稳压源模块四部分,最终应用LabVIEW软件把经物体反射折算的信号频率和幅值记录到电脑里,并显示在制作好的结果界面中.     

雷达信号处理模块组件化设计与仿真

为有效提高雷达系统仿真效率,本文提出了一种雷达信号处理模块组件化设计方法。所提方法首先根据雷达信号处理各流程的独立性建立信号处理功能组件库;在此基础上根据所仿真雷达对象进行组件的选择与拼接可灵活构建出所需信号处理模块。最后通过基于Visual Studio 2013平台中构建的雷达组件化信号处理模块的系统试验证明了所提方法的有效性。     

Applicability of the relay correlator to radar signal processing

The relay estimator for evaluating the autocorrelation coefficients of a zero-mean stationary Gaussian process is characterised by a very low computational cost. This feature is particularly attractive in radar applications. In the letter its performance, for uncorrelated and correlated pairs of samples, is investigated and compared with that of the conventional estimator.