一、發(fā)展目標(biāo)與原則
I. Goals and Principles of Development

中國高度重視北斗系統(tǒng)建設(shè)，將北斗系統(tǒng)列為國家科技重大專項，支撐國家創(chuàng)新發(fā)展戰(zhàn)略。
China lays store by the construction of the BDS, ranking it one of its national key technical projects that supports its innovative development strategy.

（一）發(fā)展目標(biāo)
(I) Goals of Development

建設(shè)世界一流的衛(wèi)星導(dǎo)航系統(tǒng)，滿足國家安全與經(jīng)濟社會發(fā)展需求，為全球用戶提供連續(xù)、穩(wěn)定、可靠的服務(wù)；發(fā)展北斗產(chǎn)業(yè)，服務(wù)經(jīng)濟社會發(fā)展和民生改善；深化國際合作，共享衛(wèi)星導(dǎo)航發(fā)展成果，提高全球衛(wèi)星導(dǎo)航系統(tǒng)的綜合應(yīng)用效益。
Building a world-class navigation satellite system to meet the needs of the country’s national security as well as economic and social development, and providing continuous, stable and reliable services for global users; developing BDS-related industries to support China’s economic and social development, as well as improvement of people’ s living standards; and enhancing international cooperation to share the fruits of development in the field of satellite navigation, increasing the comprehensive application benefits of Global Navigation Satellite System (GNSS).

（二）發(fā)展原則
(II) Principles of Development

中國堅持“自主、開放、兼容、漸進”的原則建設(shè)和發(fā)展北斗系統(tǒng)。
China upholds the principles of “independence, openness, compatibility and gradualness” in the BDS construction and development.

——自主。堅持自主建設(shè)、發(fā)展和運行北斗系統(tǒng)，具備向全球用戶獨立提供衛(wèi)星導(dǎo)航服務(wù)的能力。
– By “independence,” it means to uphold independent construction, development and operation of the BDS, and acquire the capability to independently provide satellite navigation services to global users.

——開放。免費提供公開的衛(wèi)星導(dǎo)航服務(wù)，鼓勵開展全方位、多層次、高水平的國際合作與交流。
– By “openness,” it means to provide open satellite navigation services free of charge, and encourage all-scale, multilevel and high-quality international cooperation and exchange.

——兼容。提倡與其他衛(wèi)星導(dǎo)航系統(tǒng)開展兼容與互操作，鼓勵國際合作與交流，致力于為用戶提供更好的服務(wù)。
– By “compatibility,” it means to enhance BDS compatibility and interoperability with other navigation satellite systems, and encourage international cooperation and exchanges, so as to provide better services to users.

——漸進。分步驟推進北斗系統(tǒng)建設(shè)發(fā)展，持續(xù)提升北斗系統(tǒng)服務(wù)性能，不斷推動衛(wèi)星導(dǎo)航產(chǎn)業(yè)全面、協(xié)調(diào)和可持續(xù)發(fā)展。
– By “gradualness,” it means to carry out the BDS project step by step, enhance BDS service performance, and boost the development of satellite navigation industry in a comprehensive, coordinated and sustainable manner.

二、持續(xù)建設(shè)和發(fā)展北斗系統(tǒng)
II. Development of the BDS

中國始終立足于國情國力，堅持自主創(chuàng)新、分步建設(shè)、不斷完善北斗系統(tǒng)。
Based on its national conditions, China has independently developed the BDS step by step with constant improvement.

（一）實施“三步走”發(fā)展戰(zhàn)略
(I) Three-Step Strategy of Development

——第一步，建設(shè)北斗一號系統(tǒng)（也稱北斗衛(wèi)星導(dǎo)航試驗系統(tǒng)）。1994年，啟動北斗一號系統(tǒng)工程建設(shè)；2000年，發(fā)射2顆地球靜止軌道衛(wèi)星，建成系統(tǒng)并投入使用，采用有源定位體制，為中國用戶提供定位、授時、廣域差分和短報文通信服務(wù)；2003年，發(fā)射第三顆地球靜止軌道衛(wèi)星，進一步增強系統(tǒng)性能。
– The first step is to construct the BDS-1 (also known as BeiDou Navigation Satellite Demonstration System). The project was started in 1994, and the system was completed and put into operation in 2000 with the launching of two Geostationary Earth Orbit (GEO) satellites. With an active-positioning scheme, the system provided users in China with positioning, timing, wide-area differential and short message communication services. The third GEO satellite was launched in 2003, which further enhanced the system’s performance.

——第二步，建設(shè)北斗二號系統(tǒng)。2004年，啟動北斗二號系統(tǒng)工程建設(shè)；2012年年底，完成14顆衛(wèi)星（5顆地球靜止軌道衛(wèi)星、5顆傾斜地球同步軌道衛(wèi)星和4顆中圓地球軌道衛(wèi)星）發(fā)射組網(wǎng)。北斗二號系統(tǒng)在兼容北斗一號技術(shù)體制基礎(chǔ)上，增加無源定位體制，為亞太地區(qū)用戶提供定位、測速、授時、廣域差分和短報文通信服務(wù)。
– The second step is to construct the BDS-2. The project was started in 2004, and by the end of 2012 a total of 14 satellites – 5 GEO satellites, 5 Inclined Geosynchronous Satellite Orbit (IGSO) satellites and 4 Medium Earth Orbit (MEO) satellites – had been launched to finish the space constellation deployment. Based on a technical scheme which was compatible with the BDS-1, the BDS-2 added the passive-positioning scheme, and provided users in the Asia-Pacific region with positioning, velocity measurement, timing, wide-area differential and short message communication services.

——第三步，建設(shè)北斗全球系統(tǒng)。2009年，啟動北斗全球系統(tǒng)建設(shè)，繼承北斗有源服務(wù)和無源服務(wù)兩種技術(shù)體制；計劃2018年，面向“一帶一路”沿線及周邊國家提供基本服務(wù)；2020年前后，完成35顆衛(wèi)星發(fā)射組網(wǎng)，為全球用戶提供服務(wù)。
– The third step is to construct the BDS. The project was started in 2009 to inherit the technical schemes of both active and passive services. The goal is to provide basic services to the countries along the Belt and Road and in neighboring regions by 2018, and to complete the constellation deployment with the launching of 35 satellites by 2020 to provide services to global users.

（二）北斗系統(tǒng)的基本組成
(II) Main Composition of the BDS

北斗系統(tǒng)由空間段、地面段和用戶段三部分組成。
The BDS is mainly comprised of three segments: space segment, ground segment and user segment.

——空間段。北斗系統(tǒng)空間段由若干地球靜止軌道衛(wèi)星、傾斜地球同步軌道衛(wèi)星和中圓地球軌道衛(wèi)星三種軌道衛(wèi)星組成混合導(dǎo)航星座。
– The space segment. The BDS space segment is a hybrid navigation constellation consisting of GEO, IGSO and MEO satellites.

——地面段。北斗系統(tǒng)地面段包括主控站、時間同步/注入站和監(jiān)測站等若干地面站。
– The ground segment. The BDS ground segment consists of various ground stations, including master control stations, time synchronization/uplink stations, and monitoring stations.

——用戶段。北斗系統(tǒng)用戶段包括北斗兼容其他衛(wèi)星導(dǎo)航系統(tǒng)的芯片、模塊、天線等基礎(chǔ)產(chǎn)品，以及終端產(chǎn)品、應(yīng)用系統(tǒng)與應(yīng)用服務(wù)等。
– The user segment. The BDS user segment consists of various kinds of BDS basic products, including chips, modules and antennae, as well as terminals, application systems and application services, which are compatible with other systems.

（三）北斗系統(tǒng)的發(fā)展特色
(III) Characteristics of the BDS

北斗系統(tǒng)的建設(shè)實踐，實現(xiàn)了在區(qū)域快速形成服務(wù)能力、逐步擴展為全球服務(wù)的發(fā)展路徑，豐富了世界衛(wèi)星導(dǎo)航事業(yè)的發(fā)展模式。
The BDS development follows a model of developing regional service capacities, then gradually extending the service globally. This practice has enriched the development models for navigation satellite systems worldwide.

北斗系統(tǒng)具有以下特點：一是北斗系統(tǒng)空間段采用三種軌道衛(wèi)星組成的混合星座，與其他衛(wèi)星導(dǎo)航系統(tǒng)相比高軌衛(wèi)星更多，抗遮擋能力強，尤其低緯度地區(qū)性能特點更為明顯。二是北斗系統(tǒng)提供多個頻點的導(dǎo)航信號，能夠通過多頻信號組合使用等方式提高服務(wù)精度。三是北斗系統(tǒng)創(chuàng)新融合了導(dǎo)航與通信能力，具有實時導(dǎo)航、快速定位、精確授時、位置報告和短報文通信服務(wù)五大功能。
The BDS possesses the following characteristics: First, its space segment is a hybrid constellation consisting of satellites in three kinds of orbits. In comparison with other navigation satellite systems, the BDS operates more satellites in high orbits to offer better anti-shielding capabilities, which is particularly observable in terms of performance in the low-latitude areas. Second, the BDS provides navigation signals of multiple frequencies, and is able to improve service accuracy by using combined multi-frequency signals. Third, the BDS integrates navigation and communication capabilities for the first time, and has five major functions - real-time navigation, rapid positioning, precise timing, location reporting and short message communication services.

（四）持續(xù)提升北斗系統(tǒng)性能
(IV) Improvement of BDS Performance

為滿足日益增長的用戶需求，北斗系統(tǒng)將加強衛(wèi)星、原子鐘、信號體制等方面的技術(shù)研發(fā)，探索發(fā)展新一代導(dǎo)航定位授時技術(shù)，持續(xù)提升服務(wù)性能。
To meet the increasing user demand, BDS technical research and development in the areas of satellites, atomic clocks and signals will be strengthened, and a new generation of navigation, positioning and timing technologies will be explored to improve service performance.

——提供全球服務(wù)。發(fā)射新一代導(dǎo)航衛(wèi)星，研制更高性能的星載原子鐘，進一步提高衛(wèi)星性能與壽命，構(gòu)建穩(wěn)定可靠的星間鏈路；增發(fā)更多的導(dǎo)航信號，加強與其他衛(wèi)星導(dǎo)航系統(tǒng)的兼容與互操作，為全球用戶提供更好的服務(wù)。
– Providing global services. China will launch new-generation navigation satellites, develop airborne atomic clocks with enhanced performance, further improve the performance and lifetime of satellites, and build more stable and reliable inter-satellite links. It will broadcast additional navigation signals, and enhance the compatibility and interoperability with other navigation satellite systems, so as to provide better services for global users.

——增強服務(wù)能力。大力建設(shè)地面試驗驗證系統(tǒng)，實現(xiàn)星地設(shè)備全覆蓋測試驗證；持續(xù)建設(shè)完善星基和地基增強系統(tǒng)，大幅提高系統(tǒng)服務(wù)精度和可靠性；優(yōu)化位置報告及短報文通信技術(shù)體制，擴大用戶容量，拓展服務(wù)區(qū)域。
– Strengthening service capabilities. China will establish a grounded test and validation bed to accomplish the full coverage of tests and validation for space and ground equipment; continue to build and improve satellite based and ground based augmentation systems to substantially enhance BDS service accuracy and reliability; optimize the technical system of location reporting and short message communication to expand user volume and service coverage.

——保持時空基準(zhǔn)。北斗系統(tǒng)時間基準(zhǔn)（北斗時），溯源于協(xié)調(diào)世界時，時差信息在導(dǎo)航電文中發(fā)播；推動與其他衛(wèi)星導(dǎo)航系統(tǒng)開展時差監(jiān)測，提高兼容與互操作。發(fā)展基于北斗系統(tǒng)的全球位置標(biāo)識體系，推動北斗系統(tǒng)坐標(biāo)框架與其他衛(wèi)星導(dǎo)航系統(tǒng)的互操作，并不斷精化參考框架。
– Maintaining spatio-temporal reference. The BDT is related to the Coordinated Universal Time, and the time bias information is broadcast in the navigation message. China will push forward the clock bias monitoring with other navigation satellite systems, and improve their compatibility and interoperability. It will develop a BDS-based worldwide location identification system, increase the interoperability between BDS coordinate frame and that of other navigation satellite systems, and constantly refine the reference frame.