载波相位辅助的GPS动态单点定位算法综述

对载波相位辅助条件下应用于全球定位系统（Global Positioning System,GPS）动态单点定位的各种算法进行了综合分析与比较。首先简要介绍定位算法中的基本公式与观测模型;然后分别对周跳修复与滤波解算两部分所应用的各种算法进行详细介绍并比较其性能与适用范围;最后对尚待解决的问题及可能的发展方向进行了总结。     

被动型星载氢钟H型气体电离模型及参数优化

针对被动型星载氢钟气体电离装置低功耗、低电磁干扰的设计要求,设计了一种基于平面盘绕馈能天线的H型电离系统,并建立该电离方法的数学模型。首先,由Maxwell方程出发,推导出了电离泡中的电场和磁场的分布模型,得到气体电离机制;再由电磁场的分布方程推导出氢气击穿判据表达式,建立了气体电离条件的数学模型;最后,利用电离击穿条件判据方程优化了电离装置的设计参数。数值仿真与测试表明该模型是有效的,采用优化的设计参数可以使电离功耗和电磁干扰特性得到改善,且电离直流电源总功率可小于2W。     

基于未知地标被动观测的飞航导弹SINS俯仰姿态误差估计方法

针对飞航导弹单独使用时SINS存在姿态估计精度随时间降低的问题,提出了基于未知地标被动观测的SINS俯仰姿态误差估计方法。首先,根据飞航导弹中制导段飞行的特点,把SINS俯仰姿态误差估计问题转化为攻角估计问题。然后,在不改变导弹巡航路径的前提下,利用弹上成像导引头对视场内任意未知地标连续被动观测,分别提出了弹体坐标系和速度坐标系下的攻角估计方法,并分析了观测噪声对量测方程系数的影响。最后,利用平均去噪的思想对估计结果进行处理,提高了SINS俯仰姿态误差的估计精度。仿真结果表明：两种方法都能有效估计出飞航导弹SINS俯仰姿态量测误差。     

基于 GPS 和电子海图的落水人员搜救定位系统

现阶段我国的海上搜救工作仍然采用救生衣方式的被动求救和大面积搜索的模式,搜救效率较低.为了解决了这个问题,本文设计实现了基于全球定位系统(GPS)和电子海图的落水人员搜救定位系统.该系统将 GPS、地理信息系统(GIS)、数据库同步、无线传输技术有机结合,有效保障了落水人员的精确定位,为救援船舶及时追踪落水人员提供了可靠的依据     

用于新型雷达/红外无源复合诱饵的等离子体参数选择

根据电磁波在分层介质中阻抗匹配原理,计算了非均匀非磁化等离子体平行与垂直极化波的功率反射系数。基于碱金属盐的高温电离特性,以功率反射系数为研究对象,对雷达无源诱饵用等离子体的厚度、温度和电子密度分布等参数选择进行了分析,并根据所选择的参数讨论了入射角对无源诱饵应用的影响。     

多模式柔索驱动航天员训练机器人力控制

为解决长期在失重环境下生活和工作的航天员的康复训练问题,针对现有的航天员训练设备功能单一、训练效果不理想的现状,研制了多模式柔索驱动航天员训练机器人。基于模块化、可重构的机器人构型,通过机器人模拟重力环境的负载特征,把相应的载荷施加到人体上,实现航天员在失重环境下进行跑步、卧推和负重深蹲等体育训练,帮助航天员减轻或者克服空间适应综合征带来的不利影响;在此基础上提出一种机器人双闭环力控制策略,人机跑步训练实验结果表明,本文研制的多模式航天员训练机器人构型合理,控制策略有效,可以辅助在失重环境下生活和工作的航天员开展体育训练。     

A two-step robust adaptive filtering algorithm for GNSS kinematic precise point positioning

In kinematic navigation and positioning, abnormal observations and kinematic model disturbances are one of the key factors affecting the stability and reliability of positioning performance. Generally, robust adaptive filtering algorithm is used to reduce the influence of them on positioning results. However, it is difficult to accurately identify and separate the influence of abnormal observations and kinematic model disturbances on positioning results, especially in the application of kinematic Precise Point Positioning (PPP). This has always been a key factor limiting the performance of conventional robust adaptive filtering algorithms. To address this problem, this paper proposes a two-step robust adaptive filtering algorithm, which includes two filtering steps: without considering the kinematic model information, the first step of filtering only detects the abnormal observations. Based on the filtering results of the first step, the second step makes further detection on the kinematic model disturbances and conducts adaptive processing. Theoretical analysis and experiment results indicate that the two-step robust adaptive filtering algorithm can further enhance the robustness of the filtering against the influence of abnormal observations and kinematic model disturbances on the positioning results. Ultimately, improvement of the stability and reliability of kinematic PPP is significant.     

两课教师在推进科学发展观进程中的效用分析

两课教师作为思想政治教育阵地的领军人物,在贯彻落实科学发展观的进程中,转变教育理念,贯彻以人为本,全面、协调、可持续、和谐发展的教育思想,重新进行角色定位,推进科学发展观进教材、进课堂、进学生头脑的教育进程,提高思想政治教育的针对性和实效性。     

4种DGPS模块动态定位精度测试与分析

采用RTK-DGPS为参照,对GARMIN GPS15L、Ublox LEA-4S、Gstar GS-87和Gstar GS-89m-J共4种DGPS模块在单机模式、地面伪距差分模式和卫星差分模式下的动态定位精度进行了测试和分析.结果表明:(1)对于GARMIN GPS15L 和Ublox LEA-4S,单机定位精度为米级,使用地面伪距差分定位可分别提高动态定位精度20%和87%;(2)总体上看,DGPS模块的地面伪距差分定位精度优于卫星差分定位,卫星差分定位精度优于单机定位;(3)在视野狭窄地段,无论单机定位、伪距差分定位还是卫星差分定位,动态定位精度都受到一定影响,和视野开阔地段相比,精度明显下降.     

Low C/N_0 Carrier Tracking Loop Based on Optimal Estimation Algorithm in GPS Software Receivers

Suppressing jitter noises in a phase locked loop(PLL) is of great importance in order to keep precise and continuous track of global positioning system(GPS) signals characterized by low carrier-to-noise ratio(C/N0).This article proposes and analyzes an improved Kalman-filter-based PLL to process weak carrier signals in GPS software receivers.After reviewing the optimal-bandwidth-based traditional second-order PLL,a Kalman-filter-based estimation algorithm is implemented for the new PLL by decorrelating the model error noises and the measurement noises.Finally,the efficiency of this new Kalman-filter-based PLL is verified by experimental data.Compared to the traditional second-order PLL,this new PLL is in position to make correct estimation of the carrier phase differences and Doppler shifts with less overshoots and noise disturbances and keeps an effective check on the disturbances out of jitter noises in PLL.The results show that during processing normal signals,this improved PLL reduces the standard deviation from 0.010 69 cycle to 0.007 63 cycle,and for weak signal processing,the phase jitter range and the Doppler shifts can be controlled within ±17° and ±5Hz as against ±25° and ±15 Hz by the traditional PLL.