"南京卫星协会"微信公众号19日发布《关于12月17日南京区域导航信号异常情况的技术性探讨分析》。全文如 下： 为澄清公众认知误区、解读技术原理与战略价值，南京卫星应用行业协会作如下说明： 一、离线地图无法解决本次导航异常问题 本次导航失灵的核心原因是GNSS卫星信号（含北斗、GPS）受到临时干扰压制，而非网络信号中断，因此下载 离线地图并无实际意义。 从技术原理来看： 1. 离线地图的核心功能是存储地理数据，仅解决"地图显示"问题，无法替代定位信号来源； 2. 手机导航需依赖GNSS卫星信号（至少4颗卫星）解算位置坐标，再将位置信息匹配至地图，定位信号与地图 数据是相互独立的两大系统； 2025年12月17日傍晚，南京部分区域出现导航定位异常现象，引发社会广泛关注。 各会员单位及社会各界： 3. 考虑到美国与欧盟的军事绑定特性，北约体系同样依赖GPS信号频段，这种频段兼容设计构建了重要的战略 威慑——任何针对北斗民用信号的干扰，都将同步影响GPS相关应用，从根本上遏制了恶意干扰的可能性，为 我国民用导航服务筑牢安全屏障。 3. 本次干扰精准针对北斗、GPS民用频段，导致定位信号无法被接收机识别，即便搭载离线 ...

Core Viewpoint - The article discusses the navigation signal anomalies that occurred in Nanjing on December 17, 2025, emphasizing the technical reasons behind the issue and the strategic significance of the BeiDou and GPS systems' compatibility. Group 1: Navigation Signal Anomaly - The navigation failure was primarily due to temporary interference suppressing GNSS satellite signals (including BeiDou and GPS), rather than a network signal interruption, making offline maps ineffective [3][4]. - Offline maps only store geographic data and cannot replace the positioning signal source, as mobile navigation relies on GNSS signals from at least four satellites to calculate location coordinates [4]. Group 2: Strategic Significance of BeiDou and GPS Compatibility - The simultaneous impact on both BeiDou and GPS signals during the anomaly validates the strategic foresight of China's BeiDou system's civilian frequency planning [5][6]. - The compatibility of BeiDou's civilian signal (B1C frequency) with GPS's civilian signal (L1C frequency) allows for interoperability, creating a strategic balance where interference with BeiDou also affects GPS, thus deterring malicious disruptions [6]. Group 3: Military Frequency Resilience - The signal anomaly only affected civilian GNSS frequencies, while BeiDou's military frequency remained unaffected due to its separation from civilian frequencies [7]. - BeiDou's military system employs advanced anti-jamming technologies, ensuring robust resistance to interference and maintaining reliable time-space services for national defense and emergency support [7].

Core Viewpoint - On December 17, 2025, a navigation signal anomaly occurred in Nanjing, affecting multiple navigation software systems and causing delivery delays for food delivery services due to the inability to access navigation data [12][18]. Group 1: Technical Analysis of the Navigation Anomaly - The core reason for the navigation failure was temporary interference suppression of GNSS satellite signals (including Beidou and GPS), rather than a network signal interruption, making offline maps ineffective [6][20]. - Offline maps only store geographic data and cannot replace the positioning signal source, as mobile navigation relies on GNSS satellite signals to calculate location coordinates [8][21]. - The interference specifically targeted the civilian frequency bands of Beidou and GPS, leading to the inability of receivers to recognize positioning signals, resulting in navigation drift and lack of data feedback [8][22]. Group 2: Strategic Significance of Beidou and GPS Compatibility - The simultaneous impact on Beidou and GPS signals during the anomaly validates the forward-looking strategic vision of China's Beidou system's civilian frequency band planning [8][22]. - The international satellite navigation spectrum resources follow a "first come, first served" rule, with GPS having occupied core L-band resources early on, leaving limited quality spectrum for Beidou [8][22]. - The compatibility of Beidou's civilian signal (B1C band) with GPS's civilian signal (L1C band) not only breaks the spectrum resource blockade but also creates a strategic balance where interference with Beidou also affects GPS applications [8][22]. Group 3: Resilience of Beidou Military Frequency - It is important to note that the signal anomaly only affected civilian GNSS frequency bands, while Beidou's military frequencies remained completely unaffected [9][23]. - The Beidou system employs a military-civilian frequency separation design, with military frequencies being exclusive and physically isolated from civilian bands [9][23]. - The military system is equipped with advanced anti-jamming technology and adaptive filtering algorithms, providing strong resistance to interference and deception, ensuring stable and reliable time-space services for national defense and emergency support [9][23].

南京卫星应用行业协会：关于12月17日南京区域导航信号异常情况的技术性探讨分析 各会员单位及社会各界： 2025年12月17日傍晚，南京部分区域出现导航定位异常现象，引发社会广泛关注。 为澄清公众认知误区、解读技术原理与战略价值，南京卫星应用行业协会作如下说明： 一、离线地图无法解决本次导航异常问题 本次导航失灵的核心原因是GNSS卫星信号（含北斗、GPS）受到临时干扰压制，而非网络信号中断， 因此下载离线地图并无实际意义。 从技术原理来看： 2.手机导航需依赖GNSS卫星信号（至少4颗卫星）解算位置坐标，再将位置信息匹配至地图，定位信号 与地图数据是相互独立的两大系统； 3.本次干扰精准针对北斗、GPS民用频段，导致定位信号无法被接收机识别，即便搭载离线地图，也因 缺乏位置数据源出现定位漂移、无数据反馈等问题，无法实现有效导航。（离线地图更适用于公海荒漠 深山等有卫星定位信号、无通信网络信号的区域）。 二、北斗与GPS民用频段兼容的战略意义得到验证 本次异常中北斗与GPS信号同步受影响，恰恰印证了我国北斗系统民用频段规划的前瞻性战略眼光： 1.国际卫星导航频谱资源遵循"先到先得"规则，GPS早年间占据了L频 ...

Core Viewpoint - The core reason for the navigation failure in Nanjing on December 17 is the temporary interference suppression of GNSS satellite signals (including Beidou and GPS), rather than a network signal interruption, making offline map downloads ineffective [1][7]. Group 1: Technical Analysis - Offline maps only store geographic data and cannot replace the source of positioning signals, which rely on GNSS satellite signals to calculate location coordinates [9]. - The interference specifically targeted the civilian frequency bands of Beidou and GPS, preventing the positioning signals from being recognized by receivers, leading to issues like positioning drift and lack of data feedback even with offline maps [9]. - Offline maps are more suitable for areas with satellite positioning signals but without communication network signals, such as oceans, deserts, and mountains [9]. Group 2: Strategic Significance of Frequency Compatibility - The simultaneous impact on both Beidou and GPS signals during this incident validates the strategic foresight of China's Beidou system in planning civilian frequency bands [10]. - The international satellite navigation spectrum resources follow a "first come, first served" rule, with GPS having occupied core L-band resources early on, leaving limited quality spectrum for Beidou [10]. - The compatibility of Beidou's civilian signal (B1C band) with GPS's civilian signal (L1C band) not only breaks the spectrum resource blockade but also creates a strategic balance where interference with Beidou also affects GPS applications [10]. Group 3: Military Frequency Resilience - The signal anomaly only affected civilian GNSS frequency bands, while the military frequency of Beidou remained completely unaffected [11]. - Beidou employs a military-civilian frequency separation design, with military frequencies being exclusive and physically isolated from civilian bands [11]. - The military system incorporates advanced anti-jamming technologies and adaptive filtering algorithms, enabling it to accurately identify and filter out interference signals, thus maintaining strong anti-jamming and anti-deception capabilities [11].