欢迎了解多星座全球导航卫星系统

• 作者: Peter Weiss
• 来源期刊: 工程（英文）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: News & Highlights
• 页码范围: 421-423,中插9-中插12
• 页数: 1页
• 语种: 英文

摘要

With the launch of a satellite in June 2020 (Fig. 1), China com-pleted BeiDou ("Big Dipper"), its global navigation satellite system (GNSS), a work-in-progress for the last 20 years [1]. BeiDou's fully operational debut coincides with the rapid buildup in the past dec-ade of the European Union's GNSS, Galileo, with 22 operational satellites at the close of 2020 (Fig. 2), as well as upgrades to Russia's GNSS, GLONASS, which attained full operation over the last eight years after shrinking to only seven satellites in 2002 [2]. Now, after more than two decades of, for the most part, only the 24–31 satellites of the US Global Positioning System (GPS) serving as global reference points of position and time for terres-trial GNSS users planet-wide, these newer systems and upgrades have dramatically increased the density of coverage by navigation satellites of nearly every square meter of Earth.