Core Viewpoint - The navigation signal anomaly in Nanjing on December 17, 2025, was caused by temporary interference with GNSS satellite signals, not by a network signal interruption, highlighting the limitations of offline maps in resolving such issues [1][2]. Technical Analysis - Offline maps only store geographic data and cannot replace the source of positioning signals, which rely on GNSS satellite signals from at least four satellites [2] - The interference specifically targeted the civilian frequency bands of Beidou and GPS, preventing the reception of positioning signals, leading to issues like position drift and lack of data feedback even with offline maps [2] - Offline maps are more suitable for areas with satellite positioning signals but without communication network signals, such as oceans or remote mountains [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 in planning its civilian frequency bands [3] - 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 [3] - 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 [3] Military Frequency Resilience - The signal anomaly only affected civilian GNSS frequency bands, while Beidou's military frequencies remained unaffected [4] - Beidou employs a military-civilian frequency separation design, with military frequencies being exclusive and physically isolated from civilian bands [4] - The military system incorporates advanced anti-jamming technologies, ensuring strong resilience against interference and deception, providing stable and reliable time-space services for national defense and emergency response [4] Industry Response - The Nanjing Satellite Application Industry Association will continue to monitor industry dynamics and share professional knowledge on satellite navigation technology to enhance public understanding [5] - The association aims to facilitate communication between enterprises and the government, encouraging participation from relevant companies without membership fees [5]

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 ...

12月19日下午，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"，具体内容如下： 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： 三、北斗军用频率具备强抗干扰能力，不受影响 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： 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 ...