Global Positioning System (GPS). Part I. Volume A. Introduction and Summary

The Global Positioning System GPS is a space-based radio navigation system which will provide suitably equipped GPS users with the capability to precisely determine three-dimensional position, velocity, and time information within designated test areas. To provide this navigation service, the GPS assembles and coordinates the operation of four system segments 1 The Space segment is composed of the space vehicle 2 The User segment is composed of several navigation equipment groups, each typically containing an antenna, processor, control and display unit, power supply, interface units, and auxiliary sensors 3 The Control segment is composed of a Master Control Station, several Monitor Stations, and an Upload Station, interconnected by a telecommunication network and supported by the USAF Satellite Control Facility and the Naval Weapons Laboratory in Dahlgren, Va., which serves as a remote computational facility, and 4 The Navigation Technology segment is composed of the Navigation Technology Satellite NTS-II, the Naval Research Laboratory Telemetry, Tracking, and Command subsystem, and a Pseudo-Random Noise Navigation Assembly. This volume provides executive overview of definition effort and highlights findings and recommendations for the development and concept validation phase efforts.