共查询到20条相似文献，搜索用时 163 毫秒
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提出一种极化干涉SAR数据滤波方法.通过结合最优干涉相干系数和Freeman-Durden分解的非监督分类方法,利用干涉信息对极化信息不敏感的体散射区域进行进一步的划分;再选择与中心像素同类且干涉相位相近的像素参与滤波,达到在滤波的同时更好地保护数据极化信息和干涉信息的目的.利用ESAR数据进行实验,证明2种改进算法在抑制相干斑的同时,能有效保持目标散射特性、数据极化信息和干涉信息. 相似文献
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采用双光束干涉测量装置,对SONY公司的LCX023CMT的薄膜晶体管液晶显示器（TFT-LCD）进行了测试利用计算机对得到的干涉条纹图像进行滤波、二值化、条纹细化和二值图像的滤波等一系列处理。计算出干涉条纹因LCD相位调制而移动的相位把参考灰度分别为255和0时测得的数据做了比较并取平均值绘制出LCD相位调制特性曲线。通过定性的分析,该方法能够在一定程度减少系统误差和随机误差在相移干涉测量中。用LCD代替PZT相移器能大大简化光路系统,同时避免机械运动。实现相移量的全数字化控制。 相似文献
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应用电子散斑干涉技术测量物体微小位移时,图像实时采集和快速处理是提高测量效率的关键,该系统基于matlab GUI在图像采集卡上做二次开发,实现了干涉图像的实时采集,并利用matlab图像处理工具箱提供的图像处理函数对采集的干涉图像进行快速处理,得到了了清晰的干涉条纹图像。实用表明,该系统具有较好的交互性和快速性。 相似文献
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干涉SAR图像数据压缩 总被引：1，自引：0，他引：1
研究干涉SAR图像数据压缩问题,提出将干涉SAR的数据压缩转化为一个幅度图像的压缩和一个干涉相位图的压缩.设计机上信号处理流程,给出基于DCT和DWT的2种机上数据压缩方法,并对其数据压缩性能进行分析.针对相干斑对干涉相位影响较大的问题,在对干涉相位图进行压缩前,插入回转中值滤波.不同信噪比下干涉SAR仿真数据和实际数据的处理结果,表明了本文方法的有效性. 相似文献
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介绍了利用雷达差分干涉测量技术对羊八井-当雄区进行了数据处理和地面形变测量的研究,获得了羊八井-当雄区差分条纹图和视向线形变位移图,通过对结果的分析,说明采用二轨雷达干涉差分测量方法提取该区域地面形变信息的效果良好. 相似文献
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《大科技．科学之谜》2008,(9):54-57
“全息照相”的原理及呈像特点是什么？——山东省淄博市一中 刘天宇
答：全息照相依据的是干涉原理,是利用物光和参考光迭加产生干涉条纹,并在感光胶片上记录干涉图样,呈现复杂的、透明度不同的花纹的照片。全息照相的呈像特点是人眼直接去看这种底片时,只能看到像指纹一样的干涉条纹,如果用激光去照射它,人眼透过底片就能看到原来被拍摄物体完全相同的三维立体像,一张全息照片即使只剩下一小部分,依然可以重现全部景物。 相似文献
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在对图像进行压缩的过程中,容易出现信息丢失的情况,导致传统图像压缩算法由于相关性低的图像也可参与等权计算,使得图像产生偏差及失真,无法有效实现图像压缩,提出一种基于干涉图加权叠加的图像压缩算法,给出高相关点的平均形变相位变化速率,依据误差传播定律,求出全部干涉图叠加后高相关点受到的大气延迟干扰,对每个图像对应的相关系数进行计算,依据模型采集高相关目标点,干涉图被叠加后,给出高相关点大气延迟对线性形变速率的干扰,通过移位操作获取样本的Exp-Golomb级数,完成编码获取数据的非负映射操作,利用上一个样本的Exp-Golomb编码级数对当前样本值级数进行估测,通过计算原始干涉图数据和压缩后的干涉图数据的压缩比与峰值信噪比,对压缩效果进行度量。通过光谱相对均方误差RQE对压缩前后的原始光谱和复原光谱进行度量。仿真实验结果表明,所提方法具有很高的精度。 相似文献
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The conventional logarithm cost-based adaptive filters, e.g., the least mean logarithmic square (LMLS) algorithm, cannot combat impulsive noises at the filtering process. To address this issue, we present a novel robust least mean logarithmic square (RLMLS) algorithm by using a generalized logarithmic cost function. The proposed RLMLS algorithm can provide robustness against impulsive noises with the improvement of filtering accuracy. For theoretical analysis, the mean square analysis of RLMLS is provided in terms of the mean square deviation (MSD) and excess mean-square error (EMSE) with a white Gaussian reference. For further performance improvement in different noises, the variable step-size RLMLS (VSSRLMLS) based on the statistics of error is proposed to improve the convergence rate and steady-state mean square error, simultaneously. Analytical results and superiorities of RLMLS and VSSRLMLS in the context of system identification are supported by simulations from the aspects of filtering accuracy and robustness in Gaussian and impulse noises. 相似文献
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针对传统多带宽合成孔径雷达系统需要多个滤波器和多种采样时钟等问题,提出一种新的数字处理方法,并详细介绍了算法方案、仿真结果和基于现场可编程门阵列(FPGA)的算法实现.该方法仅需一个最高频率的采样时钟获取离散化数据,通过对数据的插值得到其他较低时钟频率的数据,而对不同带宽信号的滤波由数字滤波器来实现.这种方法简化了系统设计,提高了系统可靠性. 相似文献
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本文基于Matlab的GUI界面设计开发数字图像处理实验平台。该平台不但能够在界面输入空间域算子,实现图像的空间域滤波处理,而且可以在频域选择不同的滤波器类型,对图像在频率域进行数字滤波。该实验平台能够帮助学生更直观和生动的掌握数字图像处理算法的基本理论和实验方法。 相似文献
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In this paper, we propose an adapt-then-combine (ATC) diffusion normalized Huber adaptive filtering (ATC-DNHuber) algorithm for distributed estimation in impulsive interference environments. Firstly, a normalized Huber adaptive filter (NHuber) is developed to reduce the effect of the eigenvalue spread of the input signal. Then we extend the NHuber to develop an ATC diffusion algorithm by applying the NHuber algorithm at all agents. In addition, the mean stability performance and computational complexity are analyzed theoretically. In addition, Furthermore, simulation results demonstrate that the ATC-DNHuber algorithm can perform better in identifying the unknown coefficients under the complex and changeable impulsive interference environments. 相似文献
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针对机载双天线InSAR系统实用化测图问题,提出一种将目标定位至数据获取几何的成像算法.该算法可以高效结合自配准处理.相对于将目标定位至零多普勒几何的传统算法,该算法优势在于减少了后续干涉处理过程三维定位的计算量,且成像算法效率与传统算法一致.该算法尤其适用于实用化机载双天线InSAR系统. 相似文献
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In the application of 2-D adaptive filters, a large amount of data must be processed and real-time processing is often required. In this paper, a new parallel-form realization of 2-D adaptive separable-denominator state-space filters suitable for high-speed processing is proposed. First, the 2-D local state-space model suitable for parallel processing is introduced. Next, the adaptive algorithm for this model is developed. This algorithm is based on the delayed least mean square (DLMS) method. In addition, the computation time required for the update of the coefficients is investigated. Finally, the proposed technique is applied to the design of 2-D digital filters in the spatial domain. 相似文献
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《Journal of The Franklin Institute》2023,360(6):4231-4246
A robust event-triggered distributed fusion algorithm is investigated in this paper for multi-sensor systems with unknown failure rates. A detection technique based on standard Gaussian distributed filtering innovation is designed and applied to judge whether the measurement is failed. This filtering innovation can also be used to construct the event-triggered condition. Specifically, the event condition is not triggered if the innovation is below the lower event-triggered threshold and the measurement is regarded as the failure measurement if the innovation exceeds the higher threshold. In the above two cases, the sensor measurement data is not transferred to the local estimator; otherwise, it will be transferred. Then, the sequential fast covariance intersection (SFCI) fusion algorithm is used for local estimation fusion. Besides, to analyze the estimation performance, sufficient conditions are given to demonstrate the boundness of the local estimation and fusion estimation covariance. Finally, a simulation example is given to show the usefulness of the presented algorithm. 相似文献
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《Journal of The Franklin Institute》2023,360(12):9290-9306
Network security is becoming a prominent issue for the development of information technology, and intelligent network attacks pose great challenges to system security due to its strong concealment. The existence of these attacks threatens the operation process of the complicated control system. Motivated by such a security problem, we study the secure distributed filtering algorithm under a kind of complex data integrity attack which can attack in two forms. We design a detection mechanism based on local outlier factor to distinguish the rightness of exchanged data, which determines whether to fuse the estimates by comparing the local density (LD) of the estimation of each sensor. Such a detection mechanism does not need the sensor to transmit redundant data information, thus greatly saving calculation cost and improving transmission efficiency. Meanwhile, we optimize the distributed filtering algorithm and obtain a suboptimal estimation gain. Finally, we demonstrate a numerical example to verify the availability of the filtering algorithm, and explore the influence of detector parameters on the performance of the estimation system. 相似文献
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详细介绍了自适应α-β滤波算法的基本原理和其在雷达数据处理中的应用情况,并从原理上与其他两种比较常用的滤波算法的性能优劣对比;最后通过Matlab仿真对比和量化分析,进一步分析验证了自适应α-β滤波算法的适用性和实用性。 相似文献