TABLE OF CONTENTS The GPS user solution is based on Space Vehicle (SV) orbit and time scale information contained in the navigation data sets generated by the operational control segment (OCS). [1] The space assets of GPS are managed and supported by this dedicated ground-based segment, which consists of L-band facilities to continually track the GPS radio frequency navigation signals, a digital computer network to process scientific and system control data, dedicated S-band facilities to conduct duplex information transfer sessions with each individual space vehicle, dedicated secure communications datalinks to couple the globally distributed ground assets into one integrated real-time global system, and a personnel system located at the principal ground facility where dedicated members of the United States Air Force operate the complex system. Functions allocated to this segment of GPS include the operational responsibility to perform the following:
Control and maintain the status, health, and configuration of the SV Constellation.
Support the user segment with precision predictions of ephemeris and time scale calibration data. Prepare and upload the formatted navigation message data sets to the SV for subsequent metered retransmission to the user community.
Monitor the quality of navigation and time transfer services as provided to the end users.
Support system interfaces to associated services (i.e., United States Naval Observatory).
Manage and schedule the ground assets of the control segment.
This chapter provides a summary description of the present OCS, which includes both the...
