It has been five years since the global Beidou system was established. Its on-orbit operation has proven that its stability, accuracy and continuity remain world-class. Today, the Beidou system serves more than 200 countries and regions.The system has achieved a jump in positioning accuracy from ten meters to sub-meters, and its time synchronization capabilities have also entered the nanosecond (one billionth of a second) era.
Since the Beidou system is so accurate, why is the navigation sometimes inaccurate when driving under an overpass?
Recently, Lin Baojun, chief designer of the Beidou-3 satellite system, said,In fact, it’s not that Beidou is inaccurate, it’s mainly that the environment of the overpass affects the signal too much.
on the one hand,Bridge piers and tall buildings will block direct satellite signals.If the mobile phone cannot receive enough signals, it cannot accurately locate.
on the other hand,The remaining signal will be reflected back and forth between the bridge guardrails, mixed with normal signals, deceiving the mobile phone, causing the positioning to drift on and off the bridge, or lag.
"Our current navigation system has indeed surpassed GPS from the perspective of time and frequency," Lin Baojun said.
