GPS多基线解算模式的数学相关性分析     

王振方  梁霄  李国超 《北京测绘》2014,(5):26-28

给出了在GPS多基线解算模式下,直接形成单差观测方程和双差观测方程权阵的公式,避免了对协因数矩阵的求逆,提高了形成法方程的速度.通过算例分析比较了直接形成权阵和通过对协因数矩阵求逆得到权阵的运算速度,结果表明：直接形成权阵的方法在计算速度上具有明显的优势.  相似文献   

罗德里格矩阵在三维坐标转换中的应用研究     

赵启龙 《北京测绘》2014,(5):29-30

利用反对称矩阵和罗德里格矩阵的性质,把传统旋转角参数用反对称矩阵的3个独立元素代替,推导了用三个公共点坐标计算7个参数的公式,并建立了相应的平差模型.并通过实测数据,验证了该方法的可行性.  相似文献   

基于罗德里格矩阵的混合最小二乘方法在三维激光中的应用     

田茂  花向红  丁鸽  张言锁 《测绘信息与工程》2014,(2):18-21

介绍了基于罗德里格矩阵的混合最小二乘坐标转换模型及精度,通过三维激光点云配准与坐标转换实验的结果表明,基于罗德里格矩阵的混合最小二乘方法的效果及精度明显高于基于罗德里格矩阵的最小二乘方法,说明该方法的可行性。  相似文献   

一种基于分块策略的SIFT特征快速提取与匹配方法     

闸旋  王慧  程挺  李烁  郭忠磊 《测绘科学技术学报》2014,(5)

通过研究基于GPGPU的SIFT特征匹配,提出一种通过分块处理实现大面阵遥感影像快速匹配的方法。首先采用鲁棒性强的随机采样一致性算法来估计待匹配影像间的单应关系并剔除误匹配点;然后通过单应关系找到待匹配影像间的重叠区域,进而实现大面阵遥感影像的分块SIFT特征提取和匹配。试验证明该算法可较快提取相应航摄测区的同名像点,为后续进行的光束法区域网平差提供了鲁棒的数据源。  相似文献   

双投影矩阵模型的方向关系组合推理研究     

顾卫杰  刘永山 《测绘科学技术学报》2014,(5)

将三维空间中的参照物体分别向xoy和xoz平面投影,得到的最小外接矩形将两个平面都划分成9个区域,用两个三行三列矩阵联合表示目标物体投影与两个参考区域的相交情况,据此提出了双投影方向关系矩阵模型。基于该模型,利用矩阵的计算性能,提出了一种三维空间方向关系的组合推理方法,解决了方向关系的组合推理问题。  相似文献   

ZIFs型金属有机框架材料在水处理混合基质膜中的应用进展     

徐佳  孙星  李珊  陆金仁  杨婷婷 《中国海洋大学学报(自然科学版)》2022,52(1):1-11

传统分离膜因存在渗透性和选择性相互制约、孔隙率低、膜孔尺寸不易控制、化学稳定性和热稳定性差等缺点,在诸多领域应用中受到限制。为了克服上述缺点,目前最有效的方法之一是在膜材料中掺入某些特定纳米材料作为分散相来构筑新型混合基质膜,以增强分离膜的分离性能,同时赋予抗污染性能、高强度等。沸石咪唑酯骨架材料(ZIFs)作为金属有机骨架材料(MOFs)的重要子类,具有独特的孔结构、优异的热稳定性和化学稳定性,是一类构筑混合基质膜的高性能分散相材料。本文主要对应用于水处理领域的ZIFs型混合基质膜及制备方法进行了归类和介绍,并以分离性能和运行稳定性为指标,对ZIFs在膜中掺杂的有效性进行了评估;其次概述了其在脱盐、染料废水处理、重金属离子、大分子蛋白质去除等领域的应用进展;最后总结了ZIFs型混合基质膜材料在科学研究和工程应用中存在的问题,对其今后的发展做出了展望。  相似文献   

基于改进的布尔莎-沃尔夫模型的任意旋转角坐标转换方法的研究     

张萌  杨志勇  丁克良 《北京测绘》2013,(1):16-19,35

空间直角坐标转换模型在测量中应用广泛,本文针对任意旋转角的空间坐标转换问题,提出了一种基于布尔莎-沃尔夫模型的改进算法。该算法通过采用罗德里格矩阵对坐标转换参数中的旋转矩阵进行改进,得到一种不受坐标转换旋转角大小限制的新算法。同时应用稳健估计原理,有效避免了粗差对最后结果的影响。最后引用已发表文献中的一个实例,证明了该算法的正确性。  相似文献   

Generalized penalized least squares and its statistical characteristics     

Ding Shijun  Tao Benzao 《地球空间信息科学学报》2013,16(4):255-259

The solution properties of semiparametric model are analyzed, especially that penalized least squares for semiparametric model will be invalid when the matrixBTPB is ill-posed or singular. According to the principle of ridge estimate for linear parametric model, generalized penalized least squares for semiparametric model are put forward, and some formulae and statistical properties of estimates are derived. Finally according to simulation examples some helpful conclusions are drawn.  相似文献   

Fast algorithm for maneuvering target detection in SAR imagery based on gridding and fusion of texture features     

Zhan Yuan  You He  Fuqing Cai 《地球空间信息科学学报》2013,16(3):169-176

Designing detection algorithms with high efficiency for Synthetic Aperture Radar (SAR) imagery is essential for the operator SAR Automatic Target Recognition (ATR) system. This work abandons the detection strategy of visiting every pixel in SAR imagery as done in many traditional detection algorithms, and introduces the gridding and fusion idea of different texture features to realize fast target detection. It first grids the original SAR imagery, yielding a set of grids to be classified into clutter grids and target grids, and then calculates the texture features in each grid. By fusing the calculation results, the target grids containing potential maneuvering targets are determined. The dual threshold segmentation technique is imposed on target grids to obtain the regions of interest. The fused texture features, including local statistics features and Gray-Level Co-occurrence Matrix (GLCM), are investigated. The efficiency and superiority of our proposed algorithm were tested and verified by comparing with existing fast detection algorithms using real SAR data. The results obtained from the experiments indicate the promising practical application value of our study.  相似文献   

Ground roll attenuation using a time-frequency dependent polarization filter based on the S transform     

Tan Yu-Yang  He Chuan  Wang Yan-Dong  Zhao Zhong 《应用地球物理》2013,10(3):279-294

The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequency domain cannot consider all these elements. Therefore, we have developed a time-frequency dependent polarization filter based on the S transform to attenuate the ground roll in seismic records. Our approach adopts the complex coefficients of the S transform of the multi-component seismic data to estimate the local polarization attributes and utilizes the estimated attributes to construct the filter function. In this study, we select the S transform to design this polarization filter because its scalable window length can ensure the same number of cycles of a Fourier sinusoid, thereby rendering more precise estimation of local polarization attributes. The results of applying our approach in synthetic and real data examples demonstrate that the proposed polarization filter can effectively attenuate the ground roll and successfully preserve the body wave.  相似文献