三、提供可靠安全的卫星导航服务
III. Reliable and Safe Satellite Navigation Services文章源自英文巴士-https://www.en84.com/7924.html
文章源自英文巴士-https://www.en84.com/7924.html
中国承诺采取多项措施保障系统安全稳定运行，为用户免费提供连续、稳定、可靠的公开服务。文章源自英文巴士-https://www.en84.com/7924.html
文章源自英文巴士-https://www.en84.com/7924.html
China is committed to ensuring the safe and reliable operation of the BDS by taking multiple measures, and to providing continuous, stable and reliable open services to users free of charge.文章源自英文巴士-https://www.en84.com/7924.html
文章源自英文巴士-https://www.en84.com/7924.html
（一）保障北斗系统安全稳定运行文章源自英文巴士-https://www.en84.com/7924.html
文章源自英文巴士-https://www.en84.com/7924.html
(I) Ensuring Safe and Reliable BDS Operations文章源自英文巴士-https://www.en84.com/7924.html
文章源自英文巴士-https://www.en84.com/7924.html
——完善运行管理机制。完善北斗系统空间段、地面段、用户段的多方联动的常态化机制，不断提高大型星座系统的运行管理保障能力。
– Improving the management mechanism on operation. Perfecting a normalized multi-party response mechanism for BDS space segment, ground segment and user segment. Continuously enhancing the capability of assurance to manage the operation of large-scale constellations.
——建立监测评估网络。建设全球连续监测评估系统，积极开展国际合作，广泛利用国际资源，对北斗系统星座状态、信号精度、信号质量和系统服务性能等进行全方位的监测和评估，为用户应用提供参考。
– Establishing a GNSS monitoring and assessment network. Constructing an international GNSS Monitoring and Assessment System, actively implementing international cooperation, extensively exploiting international resources, carrying out monitoring and assessment of the constellation status, signal accuracy, signal quality and service performance of the BDS at every scale, and providing references for users’ applications.
——采取冗余备份手段。采用卫星在轨、地面备份策略，避免和降低卫星突发在轨故障对系统服务性能的影响；采用地面设施的冗余备份设计，着力消除薄弱环节，增强系统可靠性。
– Taking a redundant and backup approach. Adopting a satellite backup strategy both in-orbit and on-ground to reduce and avoid the effects of emergent in-orbit satellite fault affecting service performance. Redundant and backup design is adopted to enable ground facilities to eliminate weak links, and to enhance BDS reliability.
（二）提供免费的公开服务
(II) Providing Open Services Free of Charge
目前，正在运行的北斗二号系统发播B1I和B2I公开服务信号，免费向亚太地区提供公开服务。服务区为南北纬55度、东经55度到180度区域，定位精度优于10米，测速精度优于0.2米/秒，授时精度优于50纳秒。
Currently, B1I and B2I open service signals are being broadcast by the operating BDS-2 to provide open services to the Asia-Pacific region free of charge. The services cover an area extending 55 degrees North-55 degrees South and 55 degrees East-180 degrees East, with positioning accuracy less than 10 meters, velocity measurement accuracy less than 0.2 meter per second, and timing accuracy less than 50 nanoseconds.
（三）及时发布系统信息
(III) Disseminating BDS Information in a Timely Manner
——发布北斗系统公开服务信号文件，为全球研发北斗应用产品提供输入。目前，已发布B1I、B2I信号接口控制文件，定义了北斗二号系统卫星与用户终端之间的接口关系，规范了信号结构、基本特性、测距码、导航电文等内容；已发布公开服务性能规范，定义了北斗二号系统服务覆盖范围、精度、连续性、可用性等性能指标。后续，将结合北斗系统建设发展持续更新和发布。
– Publishing BDS documents related to open services and signals to provide inputs for global BDS product development efforts. The Interface Control Document of B1I and B2I signals has been published, which defines the interface specifications between the BDS-2 satellites and user terminals. It specifies the signal structures, basic characteristics, ranging codes, NAV messages and other contents. The Open Service Performance Standard has been published, which defines the service coverage area, accuracy, continuity, availability, and other performance indexes of the BDS-2. In the future, related documents will be updated and published in step with BDS construction and development.
——建立多渠道信息发布机制。适时召开新闻发布会，权威发布北斗系统发展重要信息；通过北斗官方网站（网址www.beidou.gov.cn），及时更新系统建设、运行、应用、国际合作等方面最新动态；在采取可能影响用户服务的计划之前，向国际社会提前发布通告。
– Establishing a multi-channel information dissemination mechanism. China holds news conferences when appropriate to disseminate important information about BDS development, and releases the latest news of the system in a timely manner through the official BDS website (www.beidou.gov.cn) from the aspects of system construction, operation, application, and international cooperation. It also issues notifications worldwide in advance before carrying out plans which might affect user services.
（四）保护卫星导航频谱使用
(IV) Protecting the Utilization of Radio-Navigation Satellite Frequency Spectrum
——依法保护卫星导航频谱。根据国家无线电频谱保护法律法规，保护北斗系统频谱使用，保障北斗系统运行和用户使用安全。
– Protecting the radio-navigation satellite frequency spectrum according to law. China protects the utilization of BDS frequency spectrum, and ensures the safety of BDS operation and BDS users pursuant to the national laws and regulations regarding the radio frequency spectrum.
——坚决抵制有害干扰。严禁生产、销售或使用卫星导航非法干扰设备，依法查处任何影响系统运行和服务的恶意干扰行为。
– Firmly rejecting harmful interference. China prohibits the production, sale and use of illegal interference devices, investigates and punishes in accordance with the law any hostile interference actions which affect the system operations and services.
