GPS World, February 2012
THE SYSTEM More GPS III Birds Launch Checkout Awarded The U S Air Force awarded Lockheed Martin a 238 million contract for production of the third and fourth satellites in the next generation GPS III constellation In May 2008 the Air Force awarded Lockheed Martin an initial contract to design develop and build the first two GPS III satellites The contract also includes options for up to 10 additional spacecraft With the most recent award the GPS III team is now on contract to deliver four GPS III space vehicles with the first launch scheduled in 2014 The Air Force has plans to build up to 32 GPS III satellites The Air Force also signed a 215 million contract with Lockheed Martin to provide a launch and checkout capability LCC to command and control all GPS III satellites from launch through early on orbit testing The LCC will be integrated into the Raytheon developed Next Generation Operational Control System OCX It includes trained satellite operators and engineering solutions in partnership with OCX to support launch early orbit operations and checkout of all GPS III satellites before the spacecraft are turned over to Air Force Space Command for operations Achieving initial launch capability in 2014 is critical to introducing new GPS capabilities on time and will enable the GPS III program to continue its production pace maximize efficiencies and reduce long term costs for the GPS enterprise as a whole said Col Bernard Gruber director of the GPS Directorate LCC will ensure we can launch in 2014 effectively closing the time gap between GPS III and the Next Generation Operational Control System Lockheed Martin is the GPS III prime contractor with teammates ITT Exelis General Dynamics Infinity Systems Engineering Honeywell ATK and other subcontractors Galileo Continued from page 9 on the E1 band using the Code Number 12 of the Galileo Interface Control Document ICD Acquisition and tracking results are reported in FIGURES 1 2 and 3 The signal was received with a C N 0 of approximately 464 dBHz and a Doppler frequency shift equal to 2595 Hz Both Galileo craft were in view on January 17 FIGURE 4 shows both the estimated Doppler and C N 0 profiles obtained from multiple measurements performed on the same time interval As a final step the demodulation of the E1b data channel has also been performed checking the navigation messages for both the satellites It has been noticed that at the moment the navigation messages present only two types of page reserved word type field with value 63 and type 0 spare Type 0 words have valid Week Number and Time Of Week fields On the other hand both the satellites broadcast a valid secondary code on their E1c pilot channels compliant with the Galileo ICD Fabio Dovis FIGURE 3 Estimated C N 0 and correlation values obtained tracking the PRN 12 FIGURE 4 Estimated Doppler and C N 0 profiles along multiple measurements performed on January 17 GPS World February 2012 www gpsworld com 10
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