BEIJING, Jan. 29 -- China will send 10 satellites to join the BeiDou Navigation Satellite System (BDS) through seven separate launches this year, the China Aerospace Science and Technology Corporation (CASC) announced Tuesday.
The launches will help complete the BDS global network by 2020, said Shang Zhi, director of the Space Department of the CASC, at a press conference, where the Blue Book of China Aerospace Science and Technology Activities was released.
According to the blue book, a total of 18 BeiDou satellites were launched in 2018, marking the completion of the BDS-3 primary system. The navigation system has started to provide global service.
As an important achievement during the past 40 years of reform and opening-up, the BDS has also been widely used to serve China's economic development.
More than 6,000 fishing boats in the eastern province of Zhejiang have been installed with the BDS ship movement monitoring system, which helps them improve positioning accuracy and promptness, according to the blue book.
About 6.17 million vehicles, 35,000 postal and express delivery vehicles and 80,000 buses in 36 major cities have been installed or are compatible with the BDS. The system is also used in homemade civilian aircraft, it says.
China Post has equipped its postal vehicles with 30,000 BDS terminals and connected them with the BDS-based information management platform. E-commerce giant JD.com also arms 1,500 logistics vehicles and 2,000 couriers with smart BDS terminals, according to the blue book.
The BDS is also widely used to serve the country's agricultural production. An automatic driving system for agricultural vehicles has been put into large-scale application across the country, while the farming supervision platform based on the navigation system has served more than 50,000 farm machines and facilities.
China began to construct its navigation system, named after the Chinese term for the Big Dipper constellation, in the 1990s and started serving the Asia-Pacific region in 2017.
By the end of 2018, there were a total of 33 BDS satellites operating in orbit, including 15 BDS-2 satellites and 18 BDS-3 satellites.
Compared with the BDS-2 system, the technologies of the BDS-3 system have been greatly improved. The communications, data transmission, and ranging among satellites can be achieved through inter-satellite links.
The system's signals and positioning accuracy have also significantly improved. The BDS-3 satellites are equipped with high-precision rubidium and hydrogen atomic clocks independently developed by China.
The positioning accuracy of the system has reached 10 meters globally and five meters in the Asia-Pacific region. Its velocity accuracy is 0.2 meters per second, while its timing accuracy stands at 20 nanoseconds.
中考英语状语从句练习题及答案
英国议会抨击边境管理局
新概念教材选择英音还是美音?
网帖折射中国80后的养老焦虑
新概念英语第二册同各类考试的结合点
奥地利古堡惊现15世纪女性内衣裤
学生时代如何学习英语
专家揭示学习语言的六大成功秘诀
名师指导:如何借鉴新概念英语的文章精华
信念:地球可曾为你震动?
给新概念英语学习者几点建议
如何才能培养良好的学习习惯
新概念英语学习记忆英语单词的十种妙法
背单词的技巧方法:背一记二不过三
庭审大战揭开苹果神秘面纱
怎样培养正确的阅读习惯?
让今年更赚钱的六大投资思路
经典 经验:英语学习的两个关键词
学习英语的最高境界是什么?是习惯!
爱的真谛:是谁给我的耳朵
中考英语词汇用法复习课件(共9份打包)
中国金融改革阵痛不可避免
外滩地块引发中国开发商法律战
网络十大经典名言
新概念英语课文背诵对学习英语的重要性
你和我的伊甸园
学习英语就从VOA开始,最佳VOA学习三部曲
浅谈新概念英语五步剖析的学习方法
我是怎样将新概念英语108篇课文背诵下来的
中考英语语法第20讲课件—祈使句、感叹句
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |