共查询到19条相似文献,搜索用时 64 毫秒
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恒虚警率检测器是雷达信号处理机中的重要组成部分.对雷达自动检测和恒虚警率处理方法进行了综述,讨论了瑞利分布杂波背景中雷达目标恒虚警检测的原理,阐述了实现杂波背景中雷达目标恒虚警检测的方法. 相似文献
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为了提高毫米波雷达在多目标环境下的检测性能,在变化指数恒虚警(Variability Index CFAR,VI-CFAR)的基础上提出了一种改进算法,即当背景环境为多目标环境时,采用KL散度单元筛选恒虚警(Kullback–Leibler Trimmed Mean CFAR,KLTM-CFAR)替换单元平均恒虚警(Cell Averaging CFAR,CA-CFAR)与最小选择恒虚警(Smallest of CFAR,SO-CFAR)进行策略选择,有效避免了毫米波雷达在多目标环境下的目标遮蔽问题,提升了检测性能。对改进后的检测算法进行了仿真分析,结果表明,多目标环境下,在其他几种检测器基本丧失检测能力的情况下,该检测器仍保持着90%以上的检测概率,并且在均匀环境和杂波边缘环境下,也有较为良好的表现。 相似文献
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Performance analysis of GLRT-based adaptive detector for distributed targets in compound-Gaussian clutter 总被引:2,自引:0,他引:2
The problem of adaptive detection for spatially distributed targets in compound-Gaussian clutter is studied. We first derive the optimum NP detector and suboptimum two-step GLRT detector. For the two-step detection strategy, we also introduce three covariance matrix estimation strategies and evaluate their CFAR properties and complexity issues. Next, the numerical results are presented by means of Monte Carlo simulation strategy. In particular, the simulation results highlight that the performance loss due to adaptively estimating the texture is negligible, and that the loss due to adaptively estimating covariance matrix largely depends on the estimation algorithm, the number of the secondary data vectors and the number of the scatterers. 相似文献
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The use of genetic algorithms (GAs) tool for the solution of distributed constant false alarm rate (CFAR) detection for Weibull
clutter statistics is considered. An approximate expression of the probability of detection (P
D) of the ordered statistics CFAR (OS-CFAR) detector in Weibull clutter is derived. Optimal threshold values of distributed
maximum likelihood CFAR (ML-CFAR) detectors and distributed OS-CFAR detectors with a known shape parameter of the background
statistics are obtained using GA tool. For the distributed ML-CFAR detection, we consider also the case when the shape parameter
is unknown of the Weibull distribution. A performance assessment is carried out, and the results are compared and given as
a function of the shape parameter and of system parameters. 相似文献
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本文研究复合高斯杂波环境中的距离扩展目标的自适应检测问题。有色杂波采用参数未知的自回归(AR)过程描述。结合Wald检测准则,仅需对H1假设条件下的未知参数进行最大似然估计,给出了一种新的基于参数化模型的扩展目标检测器——参数化Wald检测器。该检测器的检验统计量可解释为首先针对各个待测单元分别计算检验统计量,然后将所有待测单元的输出进行非相参累加,其对杂波的随机功率起伏具有恒虚警率(CFAR)特性。相比于常规的基于协方差矩阵的检测方法,参数化检测算法的执行过程不需要依赖辅助数据,仅利用待测扩展目标数据即可实现自适应处理,有效缓解了训练压力并降低了计算量。仿真实验表明,所提出的参数化Wald检测器的检测性能优于之前提出的参数化广义似然比检测器的性能。 相似文献
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Vahideh Amanipour Ali Olfat 《Signal processing》2011,91(1):28-37
In this paper a multistatic radar system with n transmitters and one receiver is considered and several constant false alarm rate (CFAR) algorithms for detection are introduced. The decision statistics of the proposed detectors are the sum of the n largest returning signals in an array of N+n range cells. It is shown that the proposed decision statistic satisfies the CFAR condition and it is justified that the sum of the largest returning signals is the optimal statistic. The proposed CFAR detectors are simulated both in homogenous and non-homogenous backgrounds and their performances are compared with the performance of a monostatic radar of higher power. It is shown that a multistatic radar outperforms a monostatic radar under equal transmit power condition. 相似文献
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随着雷达分辨率的不断提高,每个距离单元中分布的杂波能量逐渐减少,当杂噪比低于10dB时,热噪声对检测性能的影响是不可以忽略的。针对低杂噪比的情况,在复合高斯杂波加热噪声的背景中研究了分布式目标的检测问题。首先假设内部热噪声和外部杂波统计独立,在给定杂波纹理分量τ的前提下,将白高斯热噪声加上由球不变随机向量表示的复合高斯杂波之后的总干扰近似等效处理成一个新的复合高斯杂波,只是将其参数做了适当调整。然后将分布式目标建模为在距离维和Doppler频率维同时扩展的子空间模型,基于Rao检验构造了N-Rao检测器。通过对N-Rao检测器虚警概率的计算表明,在不存在目标的假设下,虚警概率只由脉冲重复数N、分布式目标占据的实际距离单元数H、每个距离单元内目标散射点总数目Nt来决定,即N-RAO检测器具有恒虚警率特性。最后通过Monte Carlo仿真实验表明,杂波形状参数v的减少与CNR的增加都会使N-RAO检测器的检测性能有所提高,且在低杂噪比的情况下,N-RAO检测器有很好的检测性能。 相似文献
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This paper deals with the constant false alarm rate (CFAR) radar detection of targets embedded in Pearson distributed clutter.
We develop new CFAR detection algorithms-notably cell averaging (CA), greatest of selection (GO) and smallest of selection
SO-CFAR operating in Pearson measurements based on a non-linear compression method for spiky clutter reduction. The technique
is similar to that used in non uniform quantization where a different law is used. It consists of compressing the output square
law detector noisy signal with respect to a non-linear law in order to reduce the effect of impulsive noise level. Thus, it
can be used as a pre-processing step to improve the performance of automatic target detection especially in lower generalised
signal-to-noise ratio (GSNR). The performance characteristics of the proposed CFAR detectors are presented for different values
of the compression parameter. We demonstrate, via simulation results, that the pre-processed compression procedure is computationally
efficient and can significantly enhance detection performance. 相似文献
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AR-model-based adaptive detection of range-spread targets in compound Gaussian clutter 总被引:1,自引:0,他引:1
In this paper, we consider the problem of adaptive detection for range-spread targets with known Doppler and unknown complex amplitude in compound Gaussian clutter. The speckle component of the clutter is modeled as an autoregressive (AR) process. By using the generalized likelihood ratio test (GLRT) approach, we will first estimate the AR parameters and the unknown complex amplitude, and then propose an adaptive AR-based GLR detector. The performance assessments are presented too. The computer simulations show that the proposed detector, without a priori information of the covariance matrix, has the same asymptotical performances as the two-step GLR-based detector with known covariance matrix. 相似文献
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基于ADSP-TS201的雷达恒虚警实现 总被引:1,自引:0,他引:1
介绍了ADI公司的新一代高性能TigerSHARC处理器ADSP—TS201的性能。给出了基于ADSP—TS201的瑞利分布杂波背景中雷达目标恒虚警检测原理及软、硬件实现方法,并给出了仿真实验结果。利用ADSP—TS201的强大功能实现雷达高速信号处理。 相似文献