Core Viewpoint - The navigation signal anomaly in Nanjing on December 17, 2025, was caused by temporary interference affecting GNSS satellite signals, not by a network signal interruption [1][2]. Technical Analysis - Offline maps cannot resolve the navigation anomaly as they only store geographic data and do not replace the need for positioning signals [2][3] - Mobile navigation relies on GNSS satellite signals (at least 4 satellites) to calculate position coordinates, making positioning signals and map data independent systems [3] - The interference specifically targeted the civilian frequency bands of Beidou and GPS, leading to unrecognized positioning signals, resulting in navigation failures even with offline maps [3] Strategic Significance - The simultaneous impact on Beidou and GPS signals during the anomaly validates the strategic foresight of China's Beidou system in planning civilian frequency bands [4] - The international satellite navigation spectrum follows a "first come, first served" rule, with GPS having occupied core L-band resources early on, leaving limited quality spectrum for Beidou [4] - The compatibility of Beidou's civilian signal (B1C band) with GPS's civilian signal (L1C band) breaks the spectrum resource blockade and creates a strategic balance, where interference with Beidou also affects GPS applications [4] Military Frequency Resilience - The signal anomaly only affected civilian GNSS frequency bands, while Beidou's military frequencies remained unaffected [5] - Beidou employs a military-civilian frequency separation design, with military frequencies being exclusive and physically isolated from civilian bands [5] - The military system incorporates advanced anti-jamming technologies, ensuring robust resistance to interference and deception, thus maintaining reliable time-space services for national defense and emergency support [5] Context of the Anomaly - If the navigation anomaly was a result of temporary signal control measures for major event security, it falls within standard safety protocols, with signals gradually returning to normal post-event [6] - Reports indicated that multiple navigation software systems experienced failures, leading to delivery delays and operational issues for services like food delivery and bike-sharing [9][17]

智通财经12月19日讯，"南京卫星协会"微信公众号发布《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： 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。 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频段核心资源，北斗立项时优质频 谱已所剩无几； 2. 基于国际电联框架，北斗民用信号（B1C频段）与GPS民用信号（L1C频段）实现兼容互操作，既突 破了频谱资源封锁，更形成"干扰北斗即干扰GPS"的战略制衡； 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 ...