Microwave Journal
www.microwavejournal.com/articles/20965-exelis-delivers-critical-gps-satellite-simulation-software

Exelis delivers critical GPS satellite simulation software

November 4, 2013

Exelis successfully completed factory acceptance testing for the Global Positioning System (GPS) III navigation payload simulator software. Developed by Exelis, the software will simulate the behavior of GPS signals in space, which will be used for testing the U.S. Air Force's next generation GPS ground station known as the operational control system (OCX). The simulator will be integrated into the Raytheon-developed GPS System Simulator (GSYS) within OCX.

"The simulator models the navigation payload function and interface with OCX," said Kevin Farrell, positioning, navigation and timing general manager at Exelis Geospatial Systems. "It provides simulation data representative of multiple GPS III space vehicles at the level needed to support control segment test events, mission rehearsals, and anomaly investigations, ensuring that the OCX control system is properly functioning before launching into space."

Awarded in February 2010 by Raytheon, Exelis is on contract to provide critical software elements in the navigation processing subsystem to enable GPS constellation controllers to better understand the satellites' exact position. This helps ensure accurate navigation information is being securely broadcast to users. In addition, Exelis is building high-precision receivers for use in ground monitoring stations placed strategically around the world and also builds data encryptors to ensure secure information exchange between the ground and space segments of the system.

As part of the GPS modernization effort, Exelis is also on contract with Lockheed Martin to provide payloads for GPS III satellites. Exelis is a major space technology provider, supporting both the satellite and ground portions of the GPS III modernization program. For nearly 40 years, Exelis payloads and payload components have been on board every GPS satellite and have accumulated nearly 700 years of on-orbit life without a single mission-related failure due to Exelis equipment.

Once the new operational control segment is implemented, GPS will improve a variety of business and economic applications, including air traffic control, increasing crop yields, and monitoring environmental trends, among others. The new capabilities offered by GPS modernization will also provide U.S. Air Force Space Command increased accuracy, availability, anti-jam power and international interoperability.