jfq-105_23-31 北斗中国GPS挑战者登上世界舞台

JFQ 105, 2nd Quarter 2022 Millner, Maksim, and Huhmann 23BeiDouChinas GPS Challenger Takes Its Place on the World StageBy David H. Millner, Stephen Maksim, and Marissa HuhmannGlobal navigation satellite systems (GNSS) provide a service many people take for granted. The GNSS applications people use fall into five major categories: location (deter-mining a position), navigation (getting from one location to another), tracking (monitoring movement of people or objects), mapping (creating maps of the world), and timing (calculating time). Generally, a GNSS has a constellation of at least 24 satellites in medium-Earth orbit (about 12,550 miles high) spread out around the world to deliver global service.1 Such GNSS capabilities are considered so essential that countries and alliances are simply unwilling to rely on each other for a system that is now considered indispensable to sovereignty. GNSS supports millions of applications that track and analyze our everyday livesfrom farming, to finance, to reliable Internet. Simply put, it has become a vital service.GNSS were created almost 50 years ago when U.S. scientists pioneered Rocket carrying last satellite of BeiDou Navigation Satellite S