<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区

          Satellite navigation system launched

          Updated: 2011-12-28 07:30

          By Xin Dingding (China Daily)

            Comments() Print Mail Large Medium  Small 分享按鈕 0

          Country joins elite club as Beidou goes into operation on trial basis

          BEIJING - China started to run its own satellite positioning system, Beidou, on Tuesday as the country climbed the global tech ladder and challenged the monopoly of the West.

          Beidou, or Big Dipper, the domestic version of the US Global Positioning System (GPS), started providing navigation, positioning and timing data on a pilot basis to China and the neighboring area for free on Tuesday, Ran Chengqi, director of the China Satellite Navigation Office, said.

          The system, with 10 orbiting satellites, covers an area from Australia in the south to Russia in the north. Signals can reach the Xinjiang Uygur autonomous region in the west and the Pacific Ocean in the east, Ran said.

          With six more satellites to be launched next year, the system will cover a wider area and eventually the entire globe by 2020 with a constellation of 35 satellites, he said.

          The accuracy of the positioning service will also improve as more satellites orbit.

          During the trial run Beidou can offer positioning to within 25 meters but when the system is officially launched next year accuracy will be enhanced to within 10 meters, he said.

          With the system operational China is the third member of an elite group, along with the US and Russia, to develop a satellite navigation system.

          The US spent 20 years and more than $20 billion on the GPS. Completed in 1994, the system has 24 navigation satellites and is widely used around the world.

          Beidou has its own unique features, Ran said.

          "It not only tells users where they are and what time it is but also allows users to tell others the information through short messages," Ran said, adding that this feature is being considered by other systems.

          Russia's Glonass system achieved a 24-satellite constellation in 1996 but succumbed to funding problems.

          The rebuilding of the Glonass system is almost finished and Russian media reported that the system resumed service earlier this month.

          The European Union and the European Space Agency are building the Galileo satellite navigation system. Japan and India also intend to build independent regional navigation systems.

             Previous Page 1 2 Next Page  

          主站蜘蛛池模板: 久久精品国产99久久美女| 国产av一区二区三区区别| 欧洲亚洲国内老熟女超碰| 久久99精品久久久久麻豆| 国产精品无遮挡猛进猛出| 国产综合色产在线视频欧美| 亚洲国产系列| 国产日韩av二区三区| 精品国产自在现线看久久| 麻豆精产国品一二三区区| 亚洲色最新高清AV网站| 乱码午夜-极品国产内射| 无码日韩精品一区二区三区免费| 欧美精品在线观看视频| 国产综合色产在线精品| 国产高清精品自拍av| 国产一区二区日韩在线| 欧美日本在线一区二区三区| 亚洲国产精品视频一二区| 久久精品国产只有精品66| 色综合五月伊人六月丁香| 亚洲天堂av 在线| 国产极品美女高潮无套| 亚洲旡码欧美大片| 国产精品第12页| 亚洲男女羞羞无遮挡久久丫| 久久久久波多野结衣高潮| 中文字幕乱码一区二区免费| 午夜福利不卡片在线播放免费| 免费观看欧美猛交视频黑人| 亚洲毛片αv无线播放一区| 九九热在线免费观看视频| 国产成人久久久精品二区三区| 一区二区三区激情免费视频| 日本一卡2卡3卡4卡无卡免费| 亚洲国产精品黄在线观看| 国产精品高清一区二区三区| 苍井空一区二区三区在线观看| 国产日产亚洲系列av| 国产乱妇乱子视频在播放| 国产成人精品午夜二三区|