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True Origins and Major Original Challenges for

GPS Success (1962 – 1978)

A Tribute to the “almost forgotten” who labored and sacrificed to make it happen! *

Brad Parkinson Stanford University

10/22/09 Stanford CPNT October 2009 1 GPtS – the Stealth Utility • Pre-History and GPS Design • The Key Innovation • 5 Engineering Frontiers • GPS Applications Enabled

Note: t = TIME “Success has a thousand Fathers, failure is an orphan.“ -- Unknown Author

10/22/09 Stanford CPNT October 2009 2 Today, GPS Serves over 600 Million Users

10/22/09 Stanford CPNT October 2009 3 Summary – The GPS Concept Four or more Passive Ranging Satellite signals to solve for 4D (3 Shown for clarity)

Question: How did we come up with this design in 1973? And Where did we push the Technology/ Engineering Frontiers? Big Point: Eliminates the need for accurate clocks in the user equipment. But Leaves the major Issue: from P. Enge, Scientific American What is the form of the signal?

10/22/09 Stanford CPNT October 2009 4 The Dawn of Satellite

• 4 October 1957 - Sputnik

• US Failures and success (31 January 1958)

• William Guier and George Weiffenbach (APL) – Doppler Signature Unique – Single Pass Orbit Determination

10/22/09 Stanford CPNT October 2009 5 The Eras of

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit

10/22/09 Stanford CPNT October 2009 6 The World in 1966

• There were no: – PCs – CDs and DVDs • And– Cell there Phones/Text was no Monday night Football!!! • NorMessaging was there a GPS – but – Satellite TV – ThereInternet was an existing Satellite-based • Google Navigation System… • Facebook – eMail – iPODS – HDTV

10/22/09 Stanford CPNT October 2009 7 Navy’s Transit

• Developed by Dick Kirschner - APL • Doppler (Frequency-based) system • Polar Orbits at 1075 km. (107 Min.) • Satellite – Solar Powered – Gravity By Gradient1964, Stabilized Some People felt – Scout Launched • 150 and 400 MHzThere (Iono shouldCorrection) be a better way… • Orbit determination and prediction – 12 hrs. • Fix available every few hours • 10 to 16 minutes for a fix – 25 meters / 2D Dick Kirschner – Velocity Correction: 1 knot = 0.2 n. mi.

10/22/09 Stanford CPNT October 2009 8 Tribute to Ivan Getting (Co-recipient of the Draper Prize – 2002) Dr. Ivan Getting • Saw the need and possibilities President Aerospace Corporation • Major instigator/supporter of Key USAF/621B System Studies (1962-1972) • “Getting was a tireless advocate of the project in the face of early resistance from the Pentagon.” • While not directly involved in the GPS development, continued strong advocacy in the Pentagon 1973-1978

10/22/09 Stanford CPNT October 2009 9 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit

Competition System Study System Study Woodward 621B 621B Woodward

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) 10/22/09 Stanford CPNT October 2009 10 First “GPS” System Study- USAF 621B The 1966 Woodford/Nakamura Secret System Study Preliminary 1964 – Final Released in 1966

Originally Classified Secret and could not be discussed in Public – Not declassified until 1979 This was the real foundation of the decisions in the “Lonely-Halls” Pentagon Meeting

10/22/09 Stanford CPNT October 2009 11 First “GPS” System Study- USAF 621B The 1966 Woodford/Nakamura Secret System Study Preliminary 1964 – Final Released in 1966

A True System study: • Advocated Passive Ranging – Next step-which technique? • Advocated Atomic Clocks in Space for Navigation • Explored 4 Dimensional Navigation (triple Δρ) • User did not require an Atomic clock • Directly led to building Prototype CDMA (PRN) Navigation receivers and the USAF/621B tests at WSMR 1970-1972 10/22/09 Stanford CPNT October 2009 12 Advocacy for Atomic Clocks in USAF/621B Study of 1964-1966

10/22/09 Stanford CPNT October 2009 13 USAF/621B Study of 1964/66 Recommended Development of Space qualified Atomic Clock and Demo of tracking signal

10/22/09 Stanford CPNT October 2009 14 In-depth USAF/621B System Studies Intensified from 1966-1974 • Extended and Modified Original Study • Aerospace Library still Archives over 90 listings – – At least four are still (apparently!) classified. • Subjects Included: – Analysis of Passive Ranging Techniques • CDMA emerged as a strongest contender – 621B Receiver Accuracy – Analysis of Orbits – Error and Testing Analysis – Estimation of costs for DNSDP – Comprehensive studies of Tactical mission enhancement 10/22/09 Stanford CPNT October 2009 15 The Frontier in 1964-66 Use of Spread-Spectrum CDMA for Passive Ranging All signals at the same Frequency “Correlation” in GPS receivers identifies and locks on each one

10/22/09 Stanford CPNT October 2009 16 In 1966 -Many Questions about CDMA • Signal Acquisition (Doppler and Phase) • Ability to encrypt signal • Selection of Codes: – False Lock (Right code, wrong phase!)

– Maintaining Orthogonality for all codes (30 sats - 435 combinations) – Adding Additional Satellites • Complexity of Receiver • Rejection of Accidental or Deliberate Interference

• Communication Capability – Satellite Location and Time

10/22/09 Stanford CPNT October 2009 17 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit

Competition System Study System Study Woodward 621B 621B Woodward 621B CDMA 621B CDMA

• 1st Oper. Sys. / Transit (Jan 1964-1996) Navigation Receivers Tests Navigation Receivers Tests • New Systems Proposed (mid 1960’s) • 621B (USAF) 10/22/09 Stanford CPNT October 2009 18 USAF/621B Woodford Study – Alternative Passive Ranging Techniques (1966)

GPS (621B demo: 1971/73)

10/22/09 Stanford CPNT October 2009 19 621B Analyses and Tests of Prototype Receivers and CDMA Signal Structure 1966 -1973 • Gold Codes Invented in 1967 • Two versions of Receiver Built • Tested with CDMA passive ranging • Transmitters in an “Inverted” Satellite configuration –the Inverted Range • Verified the effectiveness of the signal structure and the ability to navigate (~5 Meters) • Results available for the “Lonely Halls” Meeting in September 1973.

10/22/09 Stanford CPNT October 2009 20 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit

Competition

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) • (NAVY)

10/22/09 Stanford CPNT October 2009 21 • Original Purpose: Quartz clocks in space for long-distance time transfer – Orbiting clocks - initially quartz – Passive side/tone ranging/cw subcarriers • could be used for 2-D positioning with user atomic clock • Timation I - May 1967 – Gravity Gradient/12 watts! – 500 n.mi./ 400 MHz – Time transfer, Oct. 1967-Mar. 1968 – Commercial double oven quartz • Timation II - Sept. ’69 – 150 and 400 MHz – 4 oven quartz – Radiation induced a high aging rate • Timation IIIA- Quartz and Rubidium - July ’74 – Renamed NTS - I - (Rb failed after about a year) • NTS - II Technology support for GPS 10/22/09 Stanford CPNT October 2009 22 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit

Competition

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) • TIMATION (NAVY) • UPGRADED TRANSIT (NAVY) • “Joint” Program Office (JPO) 1972 - Director, Col. Parkinson • “GPS” System Defined/ Labor Day 1973

10/22/09 Stanford CPNT October 2009 23 The GPS Era - Initial Chronology Two “Lucky Failures” • LGen Ken Schlutz asks Col Parkinson if he would like to dance (the 621B Fox Trot) November 1972 – Answer: Would volunteer, only if I can lead – result instant dance lessons - LF #1 • LGen Schultz suggests Dr. Currie (DDR&E) would enjoy spending the afternoon with Col Parkinson Spring 1973 – Dr. Currie becomes a champion of the cause – Protection against the Air Force reluctance – A direct, informal line between Col Parkinson and Dr. Currie • The then-current 621B proposal did not gain approval in August 1973 LF#2 • I called a small meeting to modify the proposal…

10/22/09 Stanford CPNT October 2009 24 The Pentagon “Lonely Halls” System Design Meeting • Labor Day Weekend – September 1-3, 1973 • Only JPO/Aerospace in Attendance (~12 attendees) – Attendees included: Col Brad Parkinson, Maj Gaylord Green, Maj Mel Birnbaum • Result: – Confirmation of Fundamental 621B concept • Selection of USAF/621B Signal structure • But direct to Space-hardened Atomic Clocks (Advocated by 621B and Timation – actively pursued by Timation/NRL)

• 4 Space Vehicles - Orbits modified to Inclined (Major Gaylord Green) – Not the NRL orbits – 11H 58.03M - Sidereal Semi -Synchronous (stable test area – Yuma) • Prepared Decision Coordinating Paper (DCP-133) • Approval to proceed – 22 December 1973

10/22/09 Stanford CPNT October 2009 25 Details of the evolved JPO concept - Refinement of the 1966 621B System Concept • USAF/621B signal structure (PRN code) • USAF 621B User equipment integration concepts – especially Anti Jam The new synthesis had answers to all the issues, • Inclined Maj Gaylord Green orbits (11H 58M period) but was a “go for broke” approach • EvolvedCommitted Transit orbit to Hardeneddetermination/predictions Atomic Clocks • Atomic ClocksAnd on Worldwide Spacecraft Deployment (Advocated by both 621B and NRL, Advanced development by NRL)

• Evolutionary test concept based on 621B (the ”Inverted Range”)

• A family of tailored user equipment (Manpack, Lo-cost, Multichannel) • Master control only on U.S. soil

10/22/09 Stanford CPNT October 2009 26 GPS Constellation Alternatives

Initial Evolution to Final Name Configuration Full World Control With 6 Satellites Coverage Segment Eggbeater 24 H/Day for 18 Satellites Regional Monitors 621B ~1/3 earth Frozen Regional Uploads Inclined 8 Hour 3 H/Day for 21 Satellites Regional Monitors Timation sliding regionFrozen 12 hour orbitSliding CONUS Uploads Inclined 12 Hour 4 H/Day for 18 Satellites Regional Monitors sliding region Sliding CONUS Uploads 4 H/Day for Inclined 11H 58M 18 Satellites Regional Monitors Frozen region GPS Frozen CONUS Uploads (Yuma Test Area)

Then Major Gaylord Green (JPO) suggested the frozen 12 hour configuration 10/22/09 Stanford CPNT October 2009 27 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit D-1

Competition

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) • TIMATION (NAVY) • UPGRADED TRANSIT (NAVY) • “Joint” Program Office (JPO) 1972 - Director, Col. Parkinson • “GPS” System Defined/ Labor Day 1973 • Development Approved / Dec 22, 1973

10/22/09 Stanford CPNT October 2009 28 The Most Fundamental Innovation of GPS – Spread-Spectrum (CDMA - PRN) for Passive Ranging • Studied extensively by 621B/Aerospace and Magnavox (1966-1974) • First 3D Navigation Demo -USAF 621B/ Aerospace Magnavox/Hazeltine (1971-73) • CDMA Signal Structure – All signals at same frequency • Eliminated Inter-channel Bias in Receiver • Essential for Precision Applications • Virtually unlimited number of satellites (“Gold” codes – see later!) – Code/Carrier Coherence • Enabled Hatch/Eshenbach Smoothing filter

10/22/09 Stanford CPNT October 2009 29 The Most Fundamental Innovation of GPS – Spread-Spectrum (CDMA - PRN) for Passive Ranging Additional Advantages • Easily Encrypted • Simplified Digital Sampling for User – One bit sampling is within 3 dB of Optimal – Anticipated the All - Digital Receiver • GPS Jam Resistance – Processing “Gain” of spread spectrum (PRN) signal – Inertial aiding – Directional antennas • Selected during “Lonely Halls” meeting after competition with Timation/NRL’s Side- Tone Ranging 10/22/09 Stanford CPNT October 2009 30 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit D-1 GPS-I IOC

Competition GPS Synthesis & Dev.

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) • TIMATION (NAVY) • UPGRADED TRANSIT (NAVY) • “Joint” Program Office (JPO) 1972 - Director, Col. Parkinson • “GPS” System Defined/ Labor Day 1973 • Development Approved / Dec 22, 1973

10/22/09 Stanford CPNT October 2009 31 Selecting the Signal Type was not enough… The Additional Frontiers: Five Major Engineering Challenges (For GPS Success)

1. Details of GPS CDMA signal structure ( coherence, acquisition, spreading, com. structure, error correction, message structure, etc.)

10/22/09 Stanford CPNT October 2009 32 Heroes of the GPS Signal Structure

Invention of the technique that guaranteed close to orthogonality among a family of codes – Known as the Gold Codes after Dr. Robert Gold Dr. Robert Gold Gold, R. (1967), "Optimal binary sequences for spread spectrum multiplexing (At Magnavox in 1967) (Corresp.)", IEEE Transactions on Information Theory, 13 (4), pp.619–621. But the GPS signal is Far more complex than Just codes– Those who developed the myriad of “details” – still the foundation after 34 years… Some of my personal heroes for what they did: – Magnavox and Hazeltine original 621B receivers – Maj Mel Birnbaum, Capt. Bob Rennard – Dr. Charles Kahn, Burt Glaser , Ed Martin et.al. (Magnavox) – Dr. Jim Spilker, Fran Nataly (Stanford Telecommunications) – Dr. A. J. Van Dierendonk – Joe Clifford, Bill Fees, Larry Hagerman (Aerospace) Brilliant Communication/ Navigation and Systems Engineer : Major Mel Stanford CPNT October 2009 10/22/09 Birnbaum 33 Selecting the Signal Type was not enough… The Additional Frontiers: Five Major Engineering Challenges (For GPS Success)

1. Details of GPS CDMA signal structure ( coherence, acquisition, spreading, com. structure, error correction, message structure, etc.)

2. Space-hardened (upper Van-Allen belt qualified) atomic clocks

10/22/09 Stanford CPNT October 2009 34 The Efratom Miniaturized Rubidium Clock • Atomic Clocks Invented before satellite age – Ammonium 1949 – Cesium 1957 • Co-inventors of the Miniature Rubidium Atomic Clock – early 1970’s - Commercial Endeavor

Ernst Jechert Gerhard Huebner

10/22/09 Stanford CPNT October 2009 35 GPS Space Hardened Atomic Clock

• Advocated in 1964-66 by USAF/621B • Actively pursued by NRL/Timation: – Launch of NTS-II in October of 1977 – Atomic clocks lasted ~ 1 Year (not suitable as prototypes) • First Space Qualified (Radiation-resistant) Rb clocks – Developed by JPO/Rockwell (Only clocks on first 3 GPS satellites) • Heroes – Ernst Jechert and Gerhard Huebner (Efratom) – Hugo Fruehof, Dale Ringer (Rockwell/Autonetics) – Bob Kern, Roger Easton (NRL), Ron Beard 10/22/09 Stanford CPNT October 2009 36 GPS Atomic Clocks

10/22/09 Stanford CPNT October 2009 37 Selecting the Signal Type was not enough… The Additional Frontiers: Five Major Engineering Challenges (For GPS Success)

1. Details of GPS CDMA signal structure ( coherence, acquisition, spreading, com. structure, error correction, message structure, etc.)

2. Space-hardened (upper Van-Allen belt qualified) atomic clocks 3. Orbit prediction - a few meters (URE) in 90,000 miles of travel

10/22/09 Stanford CPNT October 2009 38 Transit/APL Orbit Determination History

GPS Approval

10/22/09 Stanford CPNT October 2009 39 Challenge 3: Orbit prediction - a few meters (URE) in 90,000 miles of travel • Ancestor of GPS Orbit Determination: Transit • The GPS Design -(ASTRO/CELEST) – Passive Monitor Stations (Naval Surface Weapon Center Dahlgren Virginia) – Modified for • Complications: near real time optimal – Pole Wander prediction – Earth Tides • The Heroes – General & Special Relativity – Bob Hill, Richard J. Anderle – Noon Turn (APL) – Bill Fees (Aerospace) – Solar/Earth Radiation – Reference Station Location

10/22/09 Stanford CPNT October 2009 40 Selecting the Signal Type was not enough… The Additional Frontiers: Five Major Engineering Challenges (For GPS Success)

1. Details of GPS CDMA signal structure ( coherence, acquisition, spreading, com. structure, error correction, message structure, etc.)

2. Space-hardened (upper Van-Allen belt qualified) atomic clocks 3. Orbit prediction - a few meters (URE) in 90,000 miles of travel

4. Spacecraft lifetimes approaching ten years (GPS affordability) From The USAF/621B Woodford Study of 1964-1966:

10/22/09 Stanford CPNT October 2009 41 Sustainment of 24 Satellite Constellation – “C” (Sats per yr = C/L)

14.00 Russian GLONASS 12.00 2-3 Year Lifetime Requires 8 -12/Year 10.00 US GPS #3 -#10 10-12 Year Lifetime 8.00 Requires 2-3/Year Satellites 6.00 9.1 Years Life

4.00 First 10 GPS 2.00 Satellites

0.00 7.6 Years Life Required Satellites per year 2 3 4 5 6 7 8 9 10 11 12 Timation Average Satellite Life – “L” Experience

10/22/09 Stanford CPNT October 2009 42 Challenge 4. Spacecraft lifetimes approaching ten years (GPS affordability) Cost/yr = (Constellation Size/ Sat. Lifetime)* Cost/Satellite For Current GPS situation: 24/12*$150M = $300M/year • In 1966, 2 to 3 years was the norm • Keys to Long-life – Design with carefully selected redundancy (clocks, PA etc.) – Rigorous parts selection (Class S or equivalent) and de-rating – Test as you fly – in depth analysis of all failures

• Heroes – Dick Schwartz, Hugo Fruehauf, Rockwell – Major Gaylord Green, Major Walt Larkin GPS Program Office – Irv Rezepnick, Ed Lassiter Aerospace

10/22/09 Stanford CPNT October 2009 43 Selecting the Signal Type was not enough… The Additional Frontiers: Five Major Engineering Challenges (For GPS Success)

1. Details of GPS CDMA signal structure ( coherence, acquisition, spreading, com. structure, error correction, message structure, etc.)

2. Space-hardened (upper Van-Allen belt qualified) atomic clocks 3. Orbit prediction - a few meters (URE) in 90,000 miles of travel

4. Spacecraft lifetimes approaching ten years (GPS affordability) 5. User equipment that could eventually be miniaturized and produced at low cost.

10/22/09 Stanford CPNT October 2009 44 5. User equipment that could eventually be miniaturized and produced at low cost.

• Digital Signal and Processing the key – Selection of CDMA implied a digital signal • Integrated Circuits just beginning – Clearly the wave of the future (in 1973) – No PCs even at that stage • Wisdom of Selection has been confirmed

10/22/09 Stanford CPNT October 2009 45 One of the Phase One User Sets

10/22/09 Stanford CPNT October 2009 46 Receivers from Past to Present

Aerospace GPS Program. JPO Deputy Manager Col Don Ed Lassiter Henderson

1978 “Manpack” Today: much more on a single chip from Atheros Inc.

10/22/09 Stanford CPNT October 2009 47 High End Civil Set (Many examples from other manufacturers!)

• ~size = pack of cards • 12 Channels + WAAS • Color - Graphic display • Baro Altimeter • Magnetic Compass • Download Maps and Waypoints • ~25 hours on 2 AA Bat. • Go to Directional guidance • $219

10/22/09 Stanford CPNT October 2009 48 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit D-1 GPS-I IOC

Competition GPS Synthesis & Dev.

GULF IRAQ

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) • 621B (USAF) • TIMATION (NAVY) • UPGRADED TRANSIT (NAVY) • “Joint” Program Office (JPO) 1972 - Director, Col. Parkinson • “GPS” System Defined/ Labor Day 1973 • Development Approved / Dec 22, 1973 • GPS Operational April 1995 (21.4 yrs) 10/22/09 Stanford CPNT October 2009 49 A Fundamental Change in Warfare

10/22/09 Stanford CPNT October 2009 50 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit D-1 GPS-I IOC

Competition GPS Synthesis & Dev.

GULF IRAQ

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) Deployment • 621B (USAF) and Applications Development • TIMATION (NAVY) • UPGRADED TRANSIT (NAVY) • “Joint” Program Office (JPO) 1972 - Director, Col. Parkinson • “GPS” System Defined/ Labor Day 1973 • Development Approved / Dec 22, 1973 • GPS Operational April 1995 (21.4 yrs) 10/22/09 Stanford CPNT October 2009 51 GPtS Applications have Proliferated

• Military • Civil – Transportation • Aviation • Automobile • Maritime • Rail Control – Public Services – Timing & Frequency – – Surveillance – Other

10/22/09 Stanford CPNT October 2009 52 Cannon”s Law of Consequence “ One Thing –

Leads to Another…”

The Selection of the USAF/621B Signal has directly led to the Very High Precision Applications

10/22/09 Stanford CPNT October 2009 53 Three “Surprises” Directly Attributable to the GPS signal structure – Particularly Carrier Tracking Receivers

Robotic Use of GPS is a Major Application

10/22/09 Stanford CPNT October 2009 54 55 : Aircraft Navigation Navigation : Aircraft : Hands –Off to Touchdown! –Off to Touchdown! : Hands Demo:110 Landings with Landings Demo:110 Boeing 737 a Commercial Stanford CPNT October 2009 Stanford CPNT

One Meter The Expected in 1974 in Expected The - 1992 The Surprise 10/22/09 • • The Expected in 1974: Land Navigation The Surprise 1996: Automatic Steering to an inch 3 Axis attitude to 1.0 degrees Note four antennas to provide 1.0o Attitude

Tracking Test @ 5 m/s – worst error ~ 3 inches! Now a $400M/ year Market

Stanford Robot Tractor

10/22/09 Stanford CPNT October 2009 56 The Expected in 1974: Survey to 1 Meter The Surprise: Survey to 1 millimeter!

GPS is Vastly Juan de Fuca Instabilities Increasing our Understanding of Crustal Motion and Earthquakes Slow “earthquakes” are observed

In Canada, these events take about 15 days, propagate northward, and occur every 16-18 months.

10/22/09 Stanford CPNT October 2009 57 The Eras of Satellite Navigation

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Pioneers -Transit D-1 GPS-I IOC

Competition GPS Synthesis & Dev.

GULF IRAQ

• 1st Oper. Sys. / Transit (Jan 1964-1996) • New Systems Proposed (mid 1960’s) Deployment • 621B (USAF) and Applications Development • TIMATION (NAVY) Upgraded GPS + • UPGRADED TRANSIT (NAVY) Galileo and • “Joint” Program Office (JPO) 1972 GLONASS - Director, Col. Parkinson “Rejuvenation” • “GPS” System Defined/ Labor Day 1973 • Development Approved / Dec 22, 1973 • GPS Operational April 1995 (21.4 yrs) 10/22/09 Stanford CPNT October 2009 58 GPS Prerequisites for Success

• Well conceived System Concept – USAF/Aerospace Secret 621B Study of 1964-1966 – Refined by Aerospace (1966-1973) and TASC (Maj. Green study -1972/1973) • Jam resistant passive ranging signal – USAF 621B signal (CDMA / PRN) selected

– Demonstrated by USAF 621B (White Sands 1970-1972) • Solutions to five major, “only-engineering”

10/22/09 challenges Stanford CPNT October 2009 59 GPtS - the Stealth Utility It is truly ubiquitous • The benefits in Safety of Life, Productivity, and for our Military are now taken for granted. • We who provide GPS must insure the Service is Always Available – – To meet: the Safety, Economic, and Convenience Needs of the World

10/22/09 Stanford CPNT October 2009 60 Insuring GPS is always available: Last II-RM and Last Delta Booster (#49) 21 August 2009 Number Number still in Block Launch dates launched service I Feb 1978-Oct 11 0 Hats Off1985 to Col. Dave Madden and the II Feb 1989-Oct 9 0 current1990 generation of GPS Program IIA Nov 1990-Nov 19 12 1997 leadership!! IIR Jan 1997-Nov 12 + 12 2004 1 Working to keepfailure IIIA and OCX on track… IIRM Sep 2005-Aug 8 8 2009 IIF none yet Total Today: IIIA none yet 32

10/22/09 Stanford CPNT October 2009 61 Thanks for your Attention -

Questions?

10/22/09 Stanford CPNT October 2009 62 For the Record: Easton’s Patent (Clearly not a blueprint for GPS) • Unsuitable Signal Ranging System (Side-tone Ranging) – Not Jam Resistant – Self Jamming (would require FDMA) – We selected CDMA (demonstrated in 1969-1972) • User required an Atomic Clock • Was clearly only two dimensional

And – was issued in 1974, eight years after the defining 621B System study of 1964-1966 10/22/09 GPS World Dinner 63 USAF/621B Woodford Study – Alternative Passive Ranging Techniques (1966)

NRL Patent of 1974

GPS (621B demo: 1972/73)

10/22/09 GPS World Dinner 64 Easton Patent - Not the GPS Signal

10/22/09 GPS World Dinner 65 Easton’s User Clock

10/22/09 GPS World Dinner 66 NRL Patent: Clearly 2-dimensional

10/22/09 GPS World Dinner 67