AEP Goes Operational GPS Control Segment Upgrade Details Jun 1, 2008 By: Jack Taylor, Major James J. Pace Jr., Philip J. Mendicki, Arthur J. Dorsey

The phased transition of the 22-year-old Legacy GPS Master Control Station (MCS) to the Architecture Evolution Plan (AEP) control segment, which became operational in September 2007, constituted a multi-year cooperative effort to achieve a seamless navigation service transition to GPS users.

In a general message to all GPS users released today, the GPS Operations Center announced that it will be adding test satellite SNV23/PRN32 into the broadcast almanacs on June 27, 2007.

SVN23, the first Block IIA satellite to be launched (as PRN23), has been reactivated as PRN32. This satellite was launched on November 26, 1990, and initially decommissioned on February 13, 2004, after more than 13 years of service. SVN23/PRN32 is in slot E5 and is operating on its Rb2 clock.

Co-competitors Lockheed Martin Space Systems Corp. and Boeing Co. each received a $49,999,000 cost-plus-fixed fee contract modification to accomplish a GPS III system design review (SDR) in March 2007, towards a key decision point B in June, 2007: the award of a multi-billion dollar development contract for building GPS III.

Air Force GPS Wing Commander on Constellation Status Sep 1, 2006

Colonel Wesley A. Ballenger, Jr., Commander, Global Positioning Wing of the U.S. Air Force, spoke with GPS World editor Alan Cameron

PDF: New GPS signals and the future Galileo signals are somewhat different than the legacy signals broadcast by GPS satellites today, so new ways of accounting for biases will be needed. In this month?s column, Chris Hegarty, Ed Powers, and Blair Fonville discuss this problem.

New, Improved GPS The Legacy Accuracy Improvement Initiative Mar 1, 2006 By: Tom Creel, Arthur J. Dorsey, Philip J. Mendicki, Jon Little, Richard G. Mach, Brent A. Renfro

The GPS Legacy Accuracy Improvement Initiative has improved the accuracy of the Kalman filter state estimates, the accuracy of the broadcast ephemeris and clock parameters, and the ability to observe performance of GPS satellites.

The Defense Science Board Task Force of the Office of the Under Secretary of Defense has issued its report on The Future of the Global Positioning System.

Directions 2006