Which GNSS is operated by the United States?

Navstar is the Global Navigation Satellite System (GNSS) that is operated by the United States. It is part of the larger system known as GPS (Global Positioning System), which provides accurate positioning, navigation, and timing information worldwide. Navstar has been a vital component of navigation technologies since its initial deployment, contributing to applications ranging from civilian use to military operations.

Understanding why Navstar is the correct answer also involves recognizing the roles of the other systems listed. Galileo, operated by the European Union, is designed to provide an independent GNSS. GLONASS, developed and maintained by Russia, serves a similar purpose as GPS but with different system characteristics. Beidou is China's GNSS, designed to provide robust positioning capabilities particularly in Asia and beyond. Each of these systems operates independently of the others, making Navstar the distinct choice for the United States.