GPS航姿测定方案及误差分析

该文提出了用两台ＧＰＳ接收机测量同一颗卫星所得的伪距差求算舰船的航向角和姿态角的方法，推证了航向角和姿态角的计算公式。通过误差分析，讨论了影响ＧＰＳ航姿测定的各项误差，提出了ＧＰＳ航姿测量方案。     

GPS/DR/GIS技术在基于GSM-R列车监控系统中应用

列车监控系统是IRS(智能铁路系统 )的主要组成部分。阐述了列车监控系统的基本组成。着重介绍了GPS/DR组合定位以及GIS在列车定位和监控中的作用 ,并探讨了用GSM R移动通信网实现GPS定位数据传输的有效性     

卫星定位系统在汽车防盗中的应用

介绍了卫星定位系统的功能、应用范围,国内卫星定位系统的应用情况及其普及应用应解决的问题。     

�Զ�������λϵͳ��GPRS��·���ܷ���

介绍了基于GPRS的自动车辆定位系统的数据链路，并结合GPRS数据用户的工作流程，介绍了实现链路的关键技术。从语音传输和数据传输两个方面给出了基于GPRS数据链路的自动车辆定位系统（AVLS）系统模型。着重对数据接入延时与语音负载、数据长度、数据发送间隔、系统容量等参数之间的关系进行了仿真分析。仿真结果表明,对于语音负载小、数据长度小的自动车辆定位系统，GPRS可以用来实现系统的大容量。     

基于RTK功能的GPS道路中线测设原理与试验

介绍了GPS实时动态定位 (RTK)技术的基本原理 ,一种新的基于RTK功能的高斯平面坐标的GPS道路中线测设的原理方法 ,其中包括使用线元法解决任意复杂曲线的多种中桩点里程定义问题 ,以及区线的测设一体化技术 .介绍了相应的试验情况     

润扬长江公路大桥GPS +北斗变形监测系统应用探索

润扬大桥结构健康监测系统中的整体变形监测采用美国GPS全球卫星定位系统,主要用于监测悬索桥桥身和桥塔的结构位移.为解决GPS的RTK短期失锁问题,提高监测可靠度和精度,在润扬大桥GPS监测系统升级中,采用GPS＋北斗的新监测方法,文章介绍了GPS＋北斗监测系统的工作原理,并对其精度进行验证,结果表明,GPS与北斗卫星导航系统的联合使用提高了解算成功率,解决了RTK失锁问题.     

Monitoring Loggerhead Sea Turtle (Caretta caretta) Nests in Turkey Using GIS

Both the loggerhead sea turtle (Caretta caretta) and the green turtle (Chelonia mydas) live, feed, and nest in the Mediterranean, mostly on the beaches of Turkey and Greece. The greatest threat to the survival of Caretta caretta has been found to be on the sandy beaches where their lives begin. In this study, the digital terrain model (DTM) of the Iztuzu Beach in Turkey where the Caretta caretta sea turtles lay their eggs was prepared using a global positioning system (GPS) and a geographic information system (GIS). A flexible coastal geographic information system was prepared integrating the DTM with digitally processed satellite images and ground truth of the nesting area and its surroundings. Researchers, decision makers, other end users, or sea turtle experts can find and query any environmental information having a possible impact on the nesting area using a computer-based GIS database. A multidate monitoring of the nesting area allows users to extract and compare much information about the location and condition of the nests and will help researchers develop better strategies for protecting sea turtles.     

Global optimization method for network design problem with stochastic user equilibrium

In this paper, we consider the continuous road network design problem with stochastic user equilibrium constraint that aims to optimize the network performance via road capacity expansion. The network flow pattern is subject to stochastic user equilibrium, specifically, the logit route choice model. The resulting formulation, a nonlinear nonconvex programming problem, is firstly transformed into a nonlinear program with only logarithmic functions as nonlinear terms, for which a tight linear programming relaxation is derived by using an outer-approximation technique. The linear programming relaxation is then embedded within a global optimization solution algorithm based on range reduction technique, and the proposed approach is proved to converge to a global optimum.     

Quantifying the Difference Between Self-Reported and Global Positioning Systems-Measured Journey Durations: A Systematic Review

Accurate measurement of travel behaviour is vital for transport planning, modelling, public health epidemiology, and assessing the impact of travel interventions. Self-reported diaries and questionnaires are traditionally used as measurement tools; advances in Global Positioning Systems (GPS) technology allow for comparison. This review aimed to identify and report about studies comparing self-reported and GPS-measured journey durations. We systematically searched, appraised, and analysed published and unpublished articles from electronic databases, reference lists, bibliographies, and websites up to December 2012. Included studies used GPS and self-report to investigate trip duration. The average trip duration from each measure was compared and an aggregated, pooled estimate of the difference, weighted by number of trips, was calculated. We found 12 results from eight eligible studies. All studies showed self-reported journey times were greater than GPS-measured times. The difference between self-report and GPS times ranged from over-reporting of +2.2 to +13.5 minutes per journey. The aggregated, pooled estimate of the difference, weighted by number of trips, was over-report of +4.4 minutes (+28.6%). Studies comparing self-reported and GPS-measured journey duration have shown self-reported to be consistently over-reported across the study sample. Our findings suggest that when using self-reported journey behaviour, the journey durations should be treated as an over-estimation.     

简介面向GIS数字测图的方法

GIS产业是现代测绘行业发展的必然趋势,而面向GIS的数字测图更是测绘行业的主要发展方向。文中主要介绍了3种与GIS紧密相关的数字测图的方法,通过分析比较得出它们的优缺点,以便为今后的工作提供更好的理论依据。