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]