GPS Status and Modernization Munich Satellite Navigation Summit

GPS Status and Modernization Munich Satellite Navigation Summit Munich, Germany 3 March 2009 Colonel David Buckman, US Air Force PNT Command Lead Air Force Space Command This briefing is for information only. No US Government commitment to sell, loan, lease, co-develop or co-produce defense articles or provide defense services is implied or intended.

Overview • • GPS Overview Recent Events Modernization Improvements Summary 2

GPS Constellation • Six planes • 55 o inclination • 20, 000 km altitude • 12 -hour orbits • Twenty-four primary slots 3

GPS Ground Segment S-Band L-Band MCS at Schriever AFB, CO & Alternate MCS at VAFB Vandenberg AFB Greenland 16 Monitor Stations 6 OCS + 10 NGA 12 Ground Antennas 4 GPS + 8 AFSCN New Boston Guam GAITHERSBURG MCS Master Control Station Schriever AFB AMCS Alternate MCS Vandenberg AFB GPS Ground Antennas AFSCN Remote Tracking Stations 4

GPS – Serving the World • Constellation– the largest ever - 31 Healthy Satellites • 13 Block IIA • 12 Block IIR • 6 Block IIR-M • 31 st satellite, SVN 23, set healthy, achieved 31 healthy satellite constellation for first time ever • Most Recent Launch • IIR-19(M) – 6 th modernized SV • Launched Wednesday, 15 Mar 08 • SVN 48, PRN 7 • Set healthy on 24 Mar 08 • Next Launches • IIR-20(M) – Mar 09 – L 5 demo payload • IIR-21(M) – Aug 09 • IIF-1 – Oct 09 5

SPS Signal in Space Performance System accuracy exceeds published standard 6

GPS Modernization Program Increasing System Capabilities w Increasing Defense / Civil Benefit Block IIA/IIR Block IIR-M, IIF Block III Basic GPS • Standard Service • Single frequency (L 1) • Coarse acquisition (C/A) code navigation • Precise Service • Y-Code (L 1 Y & L 2 Y) • Y-Code navigation IIR-M: IIA/IIR capabilities plus • 2 nd civil signal (L 2 C) • M-Code (L 1 M & L 2 M) • Backward compatibility • 4 th civil signal (L 1 C) • 4 x better User Range error than IIF • Increased availability • Increased integrity IIF: IIR-M capability plus • 3 rd civil signal (L 5) • 2 Rb + 1 Cs clocks • 12 year design life 7

GPS Modernization – New Civil Signals • Second civil signal “L 2 C” • Designed to meet commercial needs • Higher accuracy through ionospheric correction • 1 st launch: Sep 2006 (GPS IIR-M); 24 satellites: ~2016 • Third civil signal “L 5” • Designed to meet demanding requirements for transportation safety-of-life • 1 st launch: ~ 2009 (GPS IIF); 24 satellites: ~2018 • Fourth civil signal “L 1 C” • Designed with international partners for GNSS interoperability • Begins with GPS Block III • 1 st launch: ~2014; 24 satellites: ~2021 8

GPS – Spectrum Block IIA 1990 P(Y) Previous Since Dec 2005 (6 SVs) Block IIR 1997 C/A Block IIR-M, 2005 L 2 C M Planned Block IIF, 2009 L 5 L 1 C L 5 RNSS Band L 2 RNSS Band L 1 Block III, 2014 (artist’s concept) RNSS Band 9

GPS Modernization – Ground • Architecture Evolution Plan (AEP) • Transitioned in 2007 • Modern distributed system replaced 1970’s era mainframe • Increased capacity for monitoring of GPS signals to 100% worldwide coverage (was 96. 4%) and have 99. 8% of world double covered • Increased worldwide commanding capability from 92. 7% to 94. 5% while providing nearly double the backup capability • Next Generation Operational Control Segment (OCX) • • • Enables modernized messaging Controls more capable GPS constellation Monitors all GPS signals Two development contracts awarded – Nov 07 Down select of contract in 2009 10

Summary • Largest constellation in history with best accuracy ever • Modernized Command Control System allows more signal monitoring and quicker satellite commanding than ever before • And we’re continuing to modernize and improve GPS even more! GPS – Serving the World 11