一种面向电力终端的北斗定位模块研究

基于电力系统对卫星导航定位的自主安全性要求,研究用于电力终端的北斗定位技术,设计了一款用于电力行业终端的北斗定位导航模块,主要包括模块的模拟前端设计、数字信号处理及分析,重点对低功耗小型化设计、提高接收灵敏度设计等进行研究,并对所设计的北斗模块实物进行了实际测试和分析,成果已开始在电力行业试点应用。     

“北斗”应用之特殊人群关爱

<正>北斗系统利用自身的导航定位、短报文等功能,为老人、儿童、残疾人等特殊人群搭建来自太空的"保护伞"。北京、上海、河北、河南、湖南、陕西、青海、江苏、四川等省相继推出北斗特殊人群关爱终端与平台。河北等省推出的北斗特殊人群关爱平台还实现了与公安系统对接。老人、儿童外出遇险时,可以通过北斗终端实现一键报警,公安系统收到报警信息第一时间进行处理,保障老人、儿童的安全。     

“北斗”应用之林业系统

<正>北斗林业应用持续推广,成效显著。尤其是湖北省,各大林业局、国有林场、国家湿地公园,纷纷下发北斗林业巡护终端,装备护林员。有了北斗林业终端,森林防火、资源监管、病虫害防治等情况通过北斗终端进行实时采集和上报,可以对林地情况进行科学有效管控,实现了"数字林场"。此外,如果林地出现灾害,北斗林业终端也可以第一时间上报灾情信息,迅速组织力量控制灾情。     

“北斗”应用之防灾减灾

<正>2016年,北斗系统为全国的防灾减灾事业锦上添花。上海、辽宁、青海、山东、山西、宁夏、福建等省相继下发北斗报灾终端,灾情险情一键上报;北京、福建、云南、湖南、西安、云南、广东等省通过北斗系统构建气象、防灾减灾系统,让防灾减灾更加科学与精确。北京市在容易出现汛情的下凹立交桥的抢险抽排位置、检查井及雨水箅子重要设施布设北斗定位终端,汛情出现时,工作人员能迅速定位,快速排水,为城市防汛提供了全新的     

“北斗”应用 落地生根 遍地开花

<正>2016年6月,中国政府发布《中国北斗卫星导航系统》白皮书,指出中国政府高度重视北斗系统应用及产业化,将北斗产业列为战略性新兴产业予以重点推进。目前,我国已形成包括基础产品、应用终端、运行服务等较为完整的北斗产业体系。目前,我国国内卫星导航总产值已达1900亿元,其中北斗系统贡献率约30%;国产北斗芯片、模块、天线等关键技术已取得全面突破,掌握卫星导航芯     

北斗/GNSS高精度时频终端测试方法探讨

基于虚拟仪器技术、网络技术和批量化测量技术,探讨北斗/GNSS高精度时频应用终端的测试手段;提出应用测试模块化和VXI/PXI/LXI总线技术的测试设计方案,该方案具有多路标准时间频率参考信号一致性设计和网络远程测试校准设计;同时,提出北斗/GNSS高精度时频终端测试校准系统的结构设计及其应用模式。这将能有效提高北斗/GNSS时频终端测试的集成化和智能化水平。     

“北斗”应用之电力行业

<正>北斗应用在电力行业不断推进的同时,青海、陕西、宁夏、新疆等省、自治区,利用北斗短报文功能开发的北斗抄表设备得到广泛应用,解决了偏远地区、无通信信号覆盖区域的电力数据采集难题。北斗系统的授时功能,较早地为电力行业的时间校准服务,中国电网进入"北斗时间"曾让国人为之振奋。2016年12月,中央电视台新闻联播报道《北斗系统首次在配电领域应用》,引起人们对于北斗电力应用的广泛关     

“北斗”卫星导航系统在公务车监管中的应用

2011年,广州市启动了公务用车使用管理信息系统建设服务项目,公务用车使用管理信息系统通过为车辆安装"北斗"卫星定位车载终端设备和身份识别装置,搭建监控中心管理平台,建立"北斗"车辆监控系统,为加强公务车辆使用管理提供强有力的信息化保障手段。     

“北斗”应用之渔业系统

<正>渔民说,现在出海就拜两样东西,一拜妈祖,二拜北斗。目前,我国渤海、黄海、东海、南海等海域的5万多条渔船装上了北斗终端。北斗系统能够快速地进行位置报告,同时具备短报文功能。在通信手段不健全、不发达的地区,北斗系统优势便会凸显,所以北斗渔业应用是北斗特色应用的重要方向之一。渔民有了北斗终端,可以跟手机进行并网运行,大大解决渔民海上通信需要,同时为沿海岛礁信息传输提供了良好的手段,近年来受到了政府部门、渔政部门     

基于GPS/北斗组合系统的高轨卫星定位技术研究

针对目前高轨GPS信号可用性差及定位精度低的特点, 对GPS/北斗组合系统的 高轨卫星定位技术进行研究, 对比分析了单GPS系统与GPS/北斗组合系统的卫 星可见性和几何精度因子. 结果表明, GPS/北斗组合系统比单GPS系统的卫星可 见性好, 且定位精度高. 同时通过提出在星载接收机上采用高精度原子钟, 可实现三星定位, 降低对接收机的技术要求.      

基于北斗三号导航系统的卫星定位技术

对北斗三号体制下的传输链路、接收门限进行理论分析,得出捕获算法采用4次非相干累加,可以使捕获灵敏度达到-130 dBm,同时实现定位时间小于5 min的综合较优结果.接着以低轨太阳同步轨道卫星为例,利用STK建模进行全轨道周期仿真,结果显示全程收星数超过4颗,定位精度达到2.59 m,速度误差为0.00378 m/s....     

Evaluation of a regional real-time precise positioning system based on GPS/BeiDou observations in Australia

The performance of real-time (RT) precise positioning can be improved by utilizing observations from multiple Global Navigation Satellite Systems (GNSS) instead of one particular system. Since the end of 2012, BeiDou, independently established by China, began to provide operational services for users in the Asia-Pacific regions. In this study, a regional RT precise positioning system is developed to evaluate the performance of GPS/BeiDou observations in Australia in providing high precision positioning services for users. Fixing three hourly updated satellite orbits, RT correction messages are generated and broadcasted by processing RT observation/navigation data streams from the national network of GNSS Continuously Operating Reference Stations in Australia (AUSCORS) at the server side. At the user side, RT PPP is realized by processing RT data streams and the RT correction messages received. RT clock offsets, for which the accuracy reached 0.07 and 0.28?ns for GPS and BeiDou, respectively, can be determined. Based on these corrections, an accuracy of 12.2, 30.0 and 45.6?cm in the North, East and Up directions was achieved for the BeiDou-only solution after 30 min while the GPS-only solution reached 5.1, 15.3 and 15.5?cm for the same components at the same time. A further improvement of 43.7, 36.9 and 45.0 percent in the three directions, respectively, was achieved for the combined GPS/BeiDou solution. After the initialization process, the North, East and Up positioning accuracies were 5.2, 8.1 and 17.8?cm, respectively, for the BeiDou-only solution, while 1.5, 3.0, and 4.7?cm for the GPS-only solution. However, we only noticed a 20.9% improvement in the East direction was obtained for the GPS/BeiDou solution, while no improvements in the other directions were detected. It is expected that such improvements may become bigger with the increasing accuracy of the BeiDou-only solution.     

基于北斗卫星反射信号的海面溢油探测方法及试验

为了监测小规模固定海域的溢油状况,针对岸基接收平台提出了一种基于北斗卫星反射信号的海面溢油探测方法,该方法将全球导航卫星系统反射信号(GNSS-R)技术应用于岸基条件下的海面溢油探测。进行了岸基试验,利用右旋圆极化(RHCP)天线和左旋圆极化(LHCP)天线分别采集北斗卫星直射与反射信号,在信号同步的基础上提取卫星直射和反射信号的相关功率,并结合北斗卫星的高度角与方位角信息,反演目标海域的介电常数来判断海面有无溢油。试验结果表明探测表面为油面时,介电常数反演结果均值为3.6,标准差为2.13,这与油的真实介电常数范围2.0~4.5一致,远小于海水介电常数,证明将GNSS-R应用到岸基海面溢油探测中具有可行性。     

低功耗环境监测系统设计与实现

以单片机MSP430F149为控制核心,辅以温度传感器、光敏传感器、无线收发模块和LCD液晶显示器等,实现了对环境温度和光信息的测量。该系统由一个监测终端和2个探测节点组成,均含有一套无线收发电路实现传输数据功能,监测终端实时显示当前能够通信的探测节点编号及探测到的环境温度和光照信息。经实验测试,该系统功耗小,使用方便。     

Inertial aided BDS triple-frequency integer ambiguity rounding method

The integer ambiguity resolution (AR) of carrier phase is significant for Global Navigation Satellite System (GNSS) precise positioning. However, in kinematic case, single-epoch AR methods based on alone GNSS are usually not reliable due to the instable pseudorange accuracy. Moreover, the computation of classical AR method Least Squares Ambiguity Decorrelation Adjustment (LAMBDA) is large. Thus, the inertial measurement unit (IMU) is introduced, a new inertial-aided AR method that directly rounds the float ambiguity of BeiDou triple-frequency combined observations, which is characterized by long wavelength, low carrier-phase noise and ionospheric delay, is proposed. The mathematical model of the new method is derived first. Then the impacts of the carrier-phase noise, ionospheric delay and inertial navigation system (INS) position error on the AR success ratio of combined observation are analyzed through probabilistic approach. Based on above investigation, the combinations (0, ?1, 1), (1, 4, ?5) and (4, ?2, ?3) are selected to resolve the original ambiguity. A vehicular integrated navigation test is performed to demonstrate the proposed method. The results show that the average AR success ratios of the three selected combinations, whose float ambiguity errors are 0.041, 0.146, 0.279 cycle respectively, are above 97.25% without regard to low-elevation C05. With respect to positioning accuracy based on our AR method when compared with IE software, the east, north, up error RMS of position are 0.042, 0.024, 0.069 m, respectively. In terms of the AR recover after the BeiDou signals outage, as long as 62 s BeiDou signal complete outage, all the ambiguities of all satellites could be re-fixed immediately. Besides, during the 90 s signals partial outage, the AR is not influenced by the position error, since the float ambiguity errors are all below half-cycle. The research of this contribution demonstrates the effectiveness of the proposed new method, which indicates it is applicable to kinematic positioning, even in BDS degraded and denied environments.     

基于北斗定位的多义路径识别解决方案

针对高速公路路网络存在的多义路径问题,提出一种基于北斗定位技术的高速公路通行卡设计方案。将北斗芯片与高速公路ETC通行卡集成,在车辆行驶过程中精确记录其位置信息,并将其与地图数据进行匹配,得到车辆的实际行驶轨迹,并以此为依据收取通行费用,有效避免多义路径现象,有助于实现高速公路大范围联网收费。与目前已有的RFID标识站方案及车牌自动识别方案相比,本方案具有识别结果精确、对现有系统改动较小、受外界影响较小等特点,具有广泛的应用价值。     

北斗D2导航电文解析和完好性性能分析

为评估北斗D2导航电文对系统空间信号完好性影响，对D2导航电文结构和内容进行研究。首先，通过基本导航信息的解析，给出了确定卫星位置和用户位置过程所需的信息和时间，并对受卫星星历和时钟影响的用户测距误差做了说明，介绍了电离层误差、对流层误差改正模型。然后，通过增强服务信息的解析，论述了完好性信息（RURA、UDRE）及格网电离层延迟的计算方法。最后给出了使用完好性信息、用户局部误差获取用户定位误差保护级的算法。     

SVRM辅助的北斗GEO卫星反射信号土壤湿度反演方法

提出了一种支持向量回归机(SVRM)辅助的北斗地球静止轨道(GEO)卫星反射信号土壤湿度反演方法。使用全球导航卫星系统反射信号(GNSS-R)右旋圆极化(RHCP)天线和左旋圆极化(LHCP)天线接收体制进行了地基实验,采集了北斗GEO卫星直射、反射信号原始数据,并从中提取直射、反射信号的相关功率,结合北斗GEO卫星的高度角与方位角信息作为输入,烘干称重法获取的土壤湿度作为输出对使用径向基(RBF)核函数的ε-SVRM进行了训练。独立测试集上的结果表明,SVRM辅助的北斗GEO卫星反射信号土壤湿度反演方法获取的土壤湿度结果与烘干称重法获取的土壤湿度参考值误差控制在3%以内,线性回归方程决定系数为0.897 9,均方根误差RMSE为1.492 6%,证明了该方法具有良好的泛化特性,实际应用中效果良好。      

Instantaneous BeiDou–GPS attitude determination: A performance analysis

The advent of modernized and new global navigation satellite systems (GNSS) has enhanced the availability of satellite based positioning, navigation, and timing (PNT) solutions. Specifically, it increases redundancy and yields operational back-up or independence in case of failure or unavailability of one system. Among existing GNSS, the Chinese BeiDou system (BDS) is being developed and will consist of geostationary (GEO) satellites, inclined geosynchronous orbit (IGSO) satellites, and medium-Earth-orbit (MEO) satellites. In this contribution, a BeiDou–GPS robustness analysis is carried out for instantaneous, unaided attitude determination.     

Ambiguity resolution performance with GPS and BeiDou for LEO formation flying

The evolving BeiDou Navigation Satellite System constellation brings new opportunities for high-precision applications. In this contribution the focus will be on one such application, namely precise and instantaneous relative navigation of a formation of LEO satellites. The aim is to assess the ambiguity resolution performance with the future GPS and BeiDou constellations depending on system choice (GPS, BeiDou, or GPS+BeiDou), single- or dual-frequency observations, receiver noise, and uncertainties in ionosphere modelling. In addition, for the GPS+BeiDou constellation it will be shown how the growing BeiDou constellation in the years to come can already bring an important performance improvement compared to the GPS-only case. The performance will be assessed based on the percentage of time that the required precision can be obtained with a partial ambiguity resolution strategy.