基于增强型GPS的自适应UKF实时星间相对定位方法   总被引：1，自引：0，他引：1  

刘洋  潘晓刚  王正明  易东云 《测绘学报》2008,37(1):0-113

高精度的星间实时相对定位是卫星编队飞行的一项关键技术。本文以双星编队为例,提出一种基于GPS双频P码、双频载波相位以及星间距离观测信息的自适应UKF、实时相对定位方法。仿真结果表明:相比传统的EKF方法,该算法能有效地提高滤波稳定性及相对定位精度,而且,星间测距信息的引入能大大减少整周模糊度判定所需的历元数。  相似文献   

On solving Kepler's equation for nearly parabolic orbits     

Richard A. Serafin 《Celestial Mechanics and Dynamical Astronomy》1996,65(4):389-398

We deal here with the efficient starting points for Kepler's equation in the special case of nearly parabolic orbits. Our approach provides with very simple formulas that allow calculating these points on a scientific vest-pocket calculator. Moreover, srtarting with these points in the Newton's method we can calculate a root of Kepler's equation with an accuracy greater than 0.001 in 0–2 iterations. This accuracy holds for the true anomaly || 135° and |e – 1| 0.01. We explain the reason for this effect also.Dedicated to the memory of Professor G.N. Duboshin (1903–1986).  相似文献   

Effect of perturbed potentials on the non-linear stability of libration pointL 4 in the restricted problem     

K. B. Bhatnagar  Usha Gupta  Rashmi Bhardwaj 《Celestial Mechanics and Dynamical Astronomy》1994,59(4):345-374

The non-linear stability of the libration pointL ₄ in the restricted problem has been studied when there are perturbations in the potentials between the bodies. It is seen that the pointL ₄ is stable for all mass ratios in the range of linear stability except for three mass ratios depending upon the perturbing functions. The theory is applied to the following four cases:

(i)	There are no perturbations in the potentials (classical problem).
(ii)	Only the bigger primary is an oblate spheroid whose axis of symmetry is perpendicular to the plane of relative motion (circular) of the primaries.
(iii)	Both the primaries are oblate spheroids whose axes of symmetry are perpendicular to the plane of relative motion (circular) of the primaries.
(iv)	The primaries are spherical in shape and the bigger is a source of radiation.

  相似文献   

Nonlinear stability of the libration points in the photogravitational restricted three body problem     

Zuzanna Niedzielska 《Celestial Mechanics and Dynamical Astronomy》1994,58(3):203-213

The stability of the triangular libration points in the case when the first and the second order resonances appear was investigated. It was proved that the first order resonances do not cause instability. The second order resonances may lead to instability. Domains of the instability in the two-dimensional parameter space were determined.  相似文献   

杠杆点评估及设计空间抗差     

黄幼才 《测绘学报》1993,22(4):289-293

本分析了杠杆点的几何含义和统计特征,从杠杆点的保差性,矩阵的摄动和参数估值可靠性的观点出发讨论了杠杆点的不利和有利的两个方面,提出了一个全面的设计空间抗差方案。  相似文献   

Infinitesimal orbits around lagrange points in the elliptic,restricted three-body problem     

Dan Şelaru  Cătălin Cucu-Dumitrescu 《Celestial Mechanics and Dynamical Astronomy》1995,61(4):333-346

This study presents a method of obtaining asymptotic approximations for motions near a Lagrange point in the planar, elliptic, restricted three-body problem by using a von Zeipel-type method. The calculations are carried out for a second-order escape solution in the proximity of the equilateral Lagrange point, L ₄, where the primaries' orbital eccentricity is taken as the small parameter .  相似文献   

基于预测的边缘检测方法   总被引：3，自引：0，他引：3  

王晖  卢健 《武汉大学学报(信息科学版)》2005,30(1):23-26

提出了一种基于预测的、有一定自适应性的边缘检测方法。介绍了其原理和算法实现过程。通过计算两个相邻像素的灰度值的均值、均方差和梯度来预测下一个像素的灰度值，比较预测值和真实值来判断下一个像素是否是边界点。通过与现有同类算法的比较，证明了该算法的优越性。  相似文献   

自适应网格技术在MM5中的应用研究     

李红莉  沈桐立 《南京气象学院学报》2005,28(1):44-50

结合一次暴雨过程，将自适应网格技术应用于中尺度模式MM5中进行数值试验，同时对比自适应网格方案和固定网格方案的优劣，对模拟结果作了诊断分析。结果表明：对于此次降水过程，自适应网格模拟的效果取决于一些参数的选择。  相似文献   

基于小波变换系数自适应阈值法在语音去噪中的应用   总被引：2，自引：0，他引：2  

孙炯宁  傅德胜  徐永华 《南京气象学院学报》2005,28(1):133-137

在软阈值去噪算法基础上，根据小波变换后信号与噪音具有的奇异性，提出无偏风险自适应阈值估计算法，并应用于语音信号的去噪处理，实验结果表明该算法的最小均方误差低于其他的去噪算法。  相似文献   

基于立体补偿的遥感立体像对压缩方法     

李飞鹏  马国锐  秦前清  李德仁 《遥感学报》2005,9(2):195-203

提出研究遥感立体像对的压缩问题。主要讨论了左右影像的视差补偿和辐射补偿。针对遥感立体像对视差分布不均以及左右影像存在辐射差的特点,提出了一种基于立体补偿的遥感立体像对压缩算法。该算法以左片为基准图像,采用自适应视差估计计算出右片的视差矢量,结合辐射校正和重叠块视差补偿技术得到平滑的右片的预测图像,以右片减去预测图像得到残差图像,然后采用小波压缩算法对残差图像进行压缩。实验结果表明,该算法能显著提高遥感立体像对的压缩性能。  相似文献