Galileo系统动态滤波的研究

提出一种Galileo动态定位滤波的方法。该方法从Galileo系统接收机输出的定位结果入手，将各种误差因素的影响等效为一个总误差，对Galileo系统接收机的机动载体加速度采用当前统计模型，利用线性卡尔曼滤波器进行动态定位数据的处理，并将次优加权自适应卡尔曼滤波算法应用到Galileo系统动态定位中。该模型简单，实时性好，滤波后定位精度得到提高。     

Galileo与GPS相位组合观测值的模型

在介绍Galileo系统空间信号的基础上,以模糊度保持整数为前提,在前人的基础上给出了Galileo系统的四个频率载波与GPS L2载波的组合相位观测值的定义,分析了组合观测值的误差传播规律.最后根据一定的组合标准论述了具有相应特性的组合观测值,并给出一些典型的组合.     

The English Galileo: Thomas Harriot and the Force of Shared Knowledge in Early Modern Mechanics

I discuss the work of the English mathematician and philosopher Thomas Harriot (1560–1621), analyzing especially his work on projectile motion, and comparing it to that of his contemporary Galileo Galilei (1564–1642). I argue that although their work on projectile motion was carried out independently and displays both similarities and differences, it shows that they focused on common challenging objects of study that embodied what I term “points of contact” between preclassical and classical mechanics. I also argue that their shared knowledge defined the space of possible solutions to the problem of projectile motion, although the inferential pathways they followed through their shared knowledge proceeded in exactly opposite directions. I conclude that their work suggests that the lines of development in early modern mechanics converged in such a way that the long-term development of science was largely unaffected by the peculiarities in an individual scientist’s work.     

Infinitesimals in the foundations of Newton's mechanics

This paper discusses two concepts of “moment” (infinitesimal) used successively by Newton in his calculus and relates these two concepts to the two concepts of force that Newton presented in Law II and Def. VIII of the Principia, to which the approximations to the action of a centripetal force known as the polygonal and parabolic models are considered to be related. It is shown that in the context of the application of the calculus to mechanics, the transition in the use of these concepts of “moment” took place in 1684, between the writing of De Motu and its first revision.     

Introducing relativity in global navigation satellite systems

Today, the Global Navigation Satellite Systems, used as global positioning systems, are the GPS and the GLONASS. They are based on a Newtonian model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c²) are: the Einstein gravitational blue shift effect of the satellite clock frequency (Equivalence Principle of General Relativity) and the Doppler red shift of second order, due to the motion of the satellite (Special Relativity). On the other hand, in a few years the Galileo system will be built, copying the GPS system unless an alternative project is designed. In this work, it will be also shown that the SYPOR project, using fully relativistic concepts, is an alternative to a mere copy of the GPS system. According to this project, the Galileo system would be exact and there would be no need for relativistic corrections.     

罗马教会对《关于托勒密和哥白尼两大世界体系的对话》的审查

给出了罗马教会在《对话》出版前对进行审查的大致过程,试图揭示当时社会教会统治的严密和伽利略在教廷和佛罗伦宫廷活动的情况。     

A new test of gravitational redshift using Galileo satellites: The GREAT experiment

We present the result of the analysis of the GREAT (Galileo gravitational Redshift test with Eccentric sATellites) experiment. An elliptic orbit induces a periodic modulation of the fractional frequency difference between a ground clock and the satellite clock, partly due to the gravitational redshift, while the good stability of Galileo clocks allows one to test this periodic modulation to a high level of accuracy. GSAT0201 and GSAT0202, with their large eccentricity and on-board H-maser clocks, are perfect candidates to perform this test. Satellite laser ranging data allows us to partly decorrelate the orbit perturbations from the clock errors. By analyzing several years of Galileo tracking data, we have been able to improve the Gravity probe A test (1976) of the gravitational redshift by a factor of 5.6, providing, to our knowledge, the first reported improvement since more than 40 years.     

Galileo E1/E5/E6数字中频信号仿真

新伽利略系统计划提供E1、E5和E6导航信号服务于民用导航、商业服务和生命安全服务领域,预计导航性能将大幅提升.本文旨在设计一种基于软件的伽利略E1/E5/E6中频信号发生器以模拟未来的伽利略导航系统.首先简要概述了伽利略信号及其在无线电频段的分布,包括E1、E5和E6信号的信号结构和特点.然后对仿真系统的组成进行了详细描述并通过Matlab软件进行仿真,重点分析了所有导航信号的功率谱密度(PSD).结果表明该仿真系统可为伽利略接收机的设计和测试提供可控信号源.     

用洛伦兹磁场力挑战狭义相对论首文的论点简

实验论证表明：基于欧式空间的伽利略相对运动,①当磁铁静止而线圈运动时,其感应电流是经典洛伦兹磁力F1的作用结果;②当线圈静止而磁铁运动时,其感应电流是广义洛伦兹磁力F2的作用结果。这就否定了狭义相对论的论点,也质疑了麦克斯韦电动力学。