CAWS600型自动气象站故障分析

1 引言 本文将自动气象站按功能划分为室外采集、通讯线路和室内监控机三部分来分析故障的排除方法.     

基于SuperMap IS.NET开发平台构建空间信息网络

我们生活在信息的海洋中,随时随地获取信息是我们的追求目标,其中位置信息可以说是最基础的信息,我们日常生活中80％以上的信息都和位置相关。以电话通讯为例,我们往往第一句就会问对方“你在哪里”,接下来告诉对方,去什么地方,怎么走。如果您在行车途中,发现车辆的油量剩余不多而需要补充,     

A Positioning System based on Communication Satellites and the Chinese Area Positioning System （CAPS）

The Chinese Area Positioning System (CAPS) is a positioning system based on satellite communication that is fundamentally different from the 3"G" (GPS, GLONASS and GALILEO) systems. The latter use special-purpose navigation satellites to broadcast navi-gation information generated on-board to users, while the CAPS transfers ground-generated navigation information to users via the communication satellite. In order to achieve accurate Positioning, Velocity and Time (PVT), the CAPS employs the following strategies to over-come the three main obstacles caused by using the communication satellite: (a) by real-time following-up frequency stabilization to achieve stable frequency; (b) by using a single carrier in the transponder with 36 MHz band-width to gain sufficient power; (c) by incorporating Decommissioned Geostationary Orbit communication satellite (DGEO), barometric pressure and Inclined Geostationary Orbit communication satellite (IGSO) to achieve the 3-D posi-tioning. Furthermore, the abundant transponders available on DGEO can be used to realize the large capacity of communication as well as the integrated navigation and communication. With the communication functions incorporated, five new functions appear in the CAPS: (1) combination of navigation and communication; (2) combination of navigation and high accu-racy orbit measurement; (3) combination of navigation message and wide/local area differen-tial processing; (4) combination of the switching of satellites, frequencies and codes; and (5) combination of the navigation message and the barometric altimetry. The CAPS is thereby labelled a PVT5C system of high accuracy. In order to validate the working principle and the performance of the CAPS, a trial system was established in the course of two years at a cost of about 20 million dollars. The trial constellation consists of two GEO satellites located at E87.5°and E110.5°, two DGEOs located at E130° and E142°, as well as barometric altimetry as a virtual satellite. Static and dynamic performance tests were completed for the Eastern, the Western, the Northern, the Southern and the Middle regions of China. The evaluation results are as follows: (1) land static test, plane accuracy range: C/A code, 15～25 m; P code, 5～10 meters; altitude accuracy range, 1～3 m; (2) land dynamic test, plane accuracy range, C/A code, 15～25 m; P code, 8～10m; (3) velocity accuracy, C/A code, 0.13～0.3 ms-1, P code, 0.15～0.17m s-1; (4) timing accuracy, C/A code, 160ns, P code, 13 ns; (5) timing compared accuracy of Two Way Satellite Time and Frequency Transfer (TWSTFT), average accuracy, 0.068 ns; (6) random error of the satellite ranging, 10.7 mm; (7) orbit determination accuracy, better than 2 m. The above stated random error is 1σ error. At present, this system is used as a preliminary operational system and a complete system with 3 GEO, 3 DGEO and 3 IGSO is being established.     

《气象知识》通讯员业务研讨会在浙江召开

5月9—10日,2012年《气象知识》通讯员业务研讨会在浙江杭州市召开。中国气象局公共气象服务中心主任（挂职浙江省气象局副局长）、《气象知识》主编毛恒青出席会议并作重要讲话。会议由公共气象服务中心科普与服务评价室主任、《气象知识》执行主编邵俊年主持。     

从学写“集纳”开始——新闻采写点滴谈之一

在与基层通讯员接触中，常听到一些初学写新闻的同志谈到，他们平时写写消息还可以，但对写通讯感到比较难，不知从何下手。特别是遇到一些生动活泼的素材，弃之可惜。写进消息里又觉得不伦不类，不知怎么办才好。根据我个人的体会，遇到这种情况，不妨试试从学写“集纳”开始，慢慢入门写通讯。     

GPS测量数据与计算机实时通信的研究与实现

介绍了GPS接收机与计算机之间实时通信的NMEA-0183数据格式，并以Leica 500系列接收机为例，介绍了如何进行GPS接收机的配置。在VC＋＋平台下，给出了3种实现方式，并讨论了每种方式的优缺点，并指出了编程时的注意事项，对于开发类似的实时通信及监测系统具有一定的借鉴作用。     

自动气象设备维护及通讯网络保障

从自动气象设备维护的角度出发,针对目前存在的问题,指出了一些注意事项,并结合工作实际,提出了在目前通讯体制下应如何作好通讯网络的保障工作.     

雷击和瞬间过电压防护技术

雷电是发生在大气层中的声、光、电物理现象，它给人类的生活带来很大影响，雷电造成的灾害自远古以来一直威胁着人类和地球上的一切生物。它是气象灾害的一种，也是世界上最具危害性的十大自然灾害之一。随着科学技术的发展，在现代化生活中，雷电除仍对生命造成危害，更严重的是对电力、广播电视、航空航天、邮电通讯、国防建设、交通运输、石油化工、电子工业等几乎是各行各业产生危害，尤其是电子计算机的普及和微电子设备对雷电电磁脉冲的敏感，     

基于GPRS网络组建地震应急流动数字地震台网的设想

详细介绍了通过红外通讯和利用GPRS网络实现计算机之间的无线连接,组建地震应急现场流动地震台网的方法.如果按照此方法即能实现对现场计算机的远程无线通讯及监视,节省人力、物力及财力.对该网络的优缺点作了分析.     

International Association of Geomorphologists Newsletter

European M anifesto on Earth H eritage and G eodiversity The IA G has joined the European Federation of G eologists,European G eoparks N etw ork,European SocietyforSoilConservation,IU G S,and IG U to supportthe European M anifesto on Earth H eritage and G…