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GPS Advanced Control Segment (OCX)


OCX represents the command and control portion of the next generation GPS. OCX will enable launch, orbit insertion, checkout, anomaly resolution and ultimately disposal of GPS III and subsequent satellites as well as control legacy satellites. OCX will provide higher accuracy, integrity and availability of the system through the combination of worldwide measurements of navigation signals, a finely tuned Kalman filter and a network to upload the commands and messages to the satellite constellation.


OCX conceived to replace OCS functionality and adds:

-- Modern flexible, adaptable, and modular architecture based on service-oriented architecture principles
-- Backward compatibility to control existing GPS satellite families
-- Ability to fly GPS III satellites, control modernized signals (M-Code, L1C, L2C, L5) and support present and future information assurance and cyber needs
-- Enable effects-based operation

Program Status

-- Contract awarded February 2010
-- Technical Baseline Review completed March 23, 2010
-- Integrated Baseline Review completed Aug. 20, 2010
-- Software Specification Review completed Sept. 23, 2010

Milestone B schedule:

-- Preliminary Design Review June 2011
-- Milestone B Approval September 2011

OCX is a Joint Requirements Oversight Committee validated program


OCX will consist of six elements:

-- Master Control Station  and Alternate Master Control Station
-- Dedicated Monitor Stations
--Ground Antennas
--Advanced Ground Antennas
--GPS System Simulator
-- Standardized Space Trainer


-- OCX provides significant Information Assurance improvements over the current GPS Operational Control Segment 

-- Prevent, detect attacks 

-- Isolate, contain and operate during cyber attacks

 -- Support higher volume near real-time command and control capability; infrastructure for net-centricity and Global Information Grid connectivity

-- New OCX remote sites eliminate "red" processing at GA/MS

-- All legacy crypto to be replaced with latest NSA approved systems

-- The MCS incorporates constellation management functions for all phases of each vehicle, through Command and Control, Mission Planning, Navigation and Data Analysis and Dissemination

-- The remote ground assets - the MS element and ground antenna assets  - support data links and signals between the control system and the space vehicles

--  The GSYS serves as a development and sustainment test driver for the MCS software and remote ground assets; the SST is a dedicated training system used for operator training

: Raytheon Information and Intelligence Systems, Aurora, Colo.