共查询到20条相似文献,搜索用时 156 毫秒
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多路径效应是近程反导武器系统中的跟踪雷达无法避免的问题。文中概述了多路径效应的数学模型和在多路径效应下传统雷达仰角角误差仿真算法,并分析了新信号处理技术下的雷达仰角角误差提取算法并在传统的数学模型基础上建立了新的数学模型。对两种角误差提取办法在理论上进行对比后,用MATLAB举例仿真了两种角误差提取办法对跟踪雷达低角跟踪仰角误差的影响,最后对仿真结果进行了分析比较,完善了雷达低角跟踪算术模型。 相似文献
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陆基雷达是战场防空和国土防御的基本装备。自二次大战后,陆基雷达得到广泛的应用。本文重点阐述了陆基防空雷达的最新发展动向:在技术上多采用三坐标体制、相控阵技术、频率捷变技术、低截获概率技术等;在设计上趋于防空与反导相结合,注重发展战术雷达系统,注重雷达系统的机动性,并对俄罗斯防空/反导雷达系统的发展状况进行了分析和研究。 相似文献
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提出一种改进的小波系数相关滤波算法。该算法在小波系数相关滤波的基础上,对去噪后的小波系数进行中值平滑,再重构新的小波系数,获得去噪后的信号。利用新的小波系数重构信号,有效降低了信号中的噪声,减少了小波相关滤波算法存在的"毛刺"。仿真试验结果表明,当信噪比在5 dB-15 dB范围内变化时,该算法在均方根误差(RMSE)和平滑度2个指标上均优于原算法,具有更好的降噪效果。 相似文献
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对于多基站雷达,站址测量偏差对系统定位误差具有较大影响.以多基站超宽带雷达系统为例,建立了偏差影响与校正模型,通过对定位误差的线性化处理,将系统定位误差表示为站址测量偏差的线性组合;引入误差系数表示线性组合的权值;重点分析了站址偏差校正算法.误差系数表征了站址偏差对定位误差的影响方式,仿真计算表明误差系数同目标与雷达各基站的相对位置有关.同时仿真结果验证了所提模型可以较好地实现对站址偏差的校正. 相似文献
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针对光学捷联导引头刻度尺误差带来的隔离度问题,提出了一种基于无迹卡尔曼滤波(UKF)的刻度尺误差实时补偿方法.分析了刻度尺误差引起隔离度问题的机理,由弹目相对运动方程以及光学捷联导引头量测方程建立了考虑刻度尺误差影响的非线性滤波模型,采用UKF滤波算法,对刻度尺系数进行估计,并用所提出的补偿方法进行实时补偿,最后进行了数学仿真及半实物仿真验证.仿真结果表明:所提方法能够有效地估计出刻度尺系数,经补偿后改善了系统的稳定性,同时提高了制导精度. 相似文献
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杂波抑制的分形处理:小波-多尺度自适应Kalman滤波 总被引:1,自引:1,他引:0
从杂波分形模型的角度,以基于小波变换和多尺度自适应Kalman滤波的方法,解决雷达信号处理中重要的杂波抑制问题。首先对接收信号作小波分解,利用小波系数建立状态方程和观测方程,用Kalman滤波对每一尺度估计分形杂波,然后从接收信号中减去估计得到的分形杂波,从而实现杂波抑制。仿真结果表明,基于小波变换和多尺度Kalman滤波的处理方法,能对分形杂波进行有效的估计分析,进而实现有效的抑制。 相似文献
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防空情报雷达反干扰能力综合分析和评估 总被引:1,自引:0,他引:1
针对在复杂电磁环境下防空情报雷达反干扰能力评估难的问题,分析了雷达反干扰能力评估的方法和准则,根据防空情报雷达自身特点,依据多属性决策方法,分别建立了分辨率、功率、频率、雷达体制和反干扰技术措施五个属性的评估模型,在此基础上建立了反干扰能力综合评估模型。在想定干扰环境下,应用评估模型对三种不同型号防空情报雷达的反干扰能力进行了计算。评估模型考虑了影响防空情报雷达反干扰能力的各种因素,所得结果能准确地反映出实际情况,具有一定的应用价值。 相似文献
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Speckle removal from SAR images in the undecimated wavelet domain 总被引:18,自引:0,他引:18
Speckle reduction is approached as a minimum mean-square error (MMSE) filtering performed in the undecimated wavelet domain by means of an adaptive rescaling of the detail coefficients, whose amplitude is divided by the variance ratio of the noisy coefficient to the noise-free one. All the above quantities are analytically calculated from the speckled image, the variance and autocorrelation of the fading variable, and the wavelet filters only, without resorting to any model to describe the underlying backscatter. On the test image Lena corrupted by synthetic speckle, the proposed method outperforms Kuan's local linear MMSE filtering by almost 3-dB signal-to-noise ratio. When true synthetic aperture radar (SAR) images are concerned, empirical criteria based on distributions of multiscale local coefficient of variation, calculated in the undecimated wavelet domain, are introduced to mitigate the rescaling of coefficients in highly heterogeneous areas where the speckle does not obey a fully developed model, to avoid blurring strong textures and point targets. Experiments carried out on widespread test SAR images and on a speckled mosaic image, comprising synthetic shapes, textures, and details from optical images, demonstrate that the visual quality of the results is excellent in terms of both background smoothing and preservation of edge sharpness, textures, and point targets. The absence of decimation in the wavelet decomposition avoids typical impairments often introduced by critically subsampled wavelet-based denoising. 相似文献
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The discrete wavelet transform (DWT) is attractive for many reasons. Its sparse sampling grid eliminates redundancy and is very efficient. Its localized basis functions are well suited for processing non–stationary signals such as transients. On the other hand, its lack of translation invariance is a major pitfall for applications such as radar and sonar, particularly in a multipath environment where numerous signal components arrive with arbitrary delays. The paper proposes the use of robust representations as a solution to the translation invariance problem. We measure robustness in terms of a mean square error for which we derive an expression that describes this translation error in the Zak domain. We develop an iterative algorithm in the Zak domain for designing increasingly robust representations. The result is an approach for generating multiresolution subspaces that retain most of their coefficient energy as the input signal is shifted. A typical robust subspace retains 98% of its energy, a significant improvement over more traditional wavelet representations. 相似文献