GLOBAL POSITIONING SYSTEM.

Abstract

Navstar is a space-based radio navigation system designed to provide US and Allied land, sea and air forces with worldwide three-dimensional position and velocity information by the late 1980's. The system consists of three segments: a space segment consisting of a full constellation of 18 operational satellites that transmit radio signals, a ground-based monitor and control segment and a variety of user-type receivers for air, land, water and space navigation and position designation. The authors give an overview of the military and commercial applications and markets.