Global Positioning Systems Wing

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Global Positioning Systems Wing
GPS Program Update to
Lt Col David B. Goldstein GPS Wing Chief
Engineer May 2009
2009 04 29 - GPSW Brief for Italy.ppt
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Agenda

• Modernization
• Constellation and Launch Status
• Cooperation with other GNSS
• Summary

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GPS Modernization New Civil Signals

• Second civil signal L2C
• Designed to meet commercial needs
• Higher accuracy through ionospheric correction
• 1st launch Sep 2006 (GPS IIR-M) 24 satellites
  2016
• Third civil signal L5
• Designed to meet demanding requirements for
  transportation safety-of-life
• 1st launch 24 Mar 09 (IIR-20(M)) 24 satellites
  2018
• Fourth civil signal L1C
• Designed with international partners for GNSS
  interoperability
• Begins with GPS Block III
• 1st launch 2014 24 satellites 2021

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GPS Spectrum
Block IIA 1990
Block IIR 1997
Previous
Since Dec 2005 (6 SVs)
Block IIR-M, 2005
Planned
Block IIF, 2009
Block III, 2014
(artists concept)
RNSS Band RNSS Band
RNSS Band
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GPS Serving the World

• Constellation one of the largest ever - 30
  Operational Satellites
• 12 Block IIA
• 12 Block IIR
• 6 Block IIR-M
• Most Recent Launch
• IIR-20(M) 7th modernized SV
• Launched 24 Mar 09
• SVN 49 / PRN 01
• L5 signal brought into use 10 Apr 09
• Next Launches
• IIR-21(M) Aug 09
• IIF-1 Late CY09, Early CY10

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SPS Signal in Space Accuracy
N/A
N/A
N/A
N/A
N/A
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Signal-in-Space User Range Error is the
difference between a GPS satellites navigation
data (position and clock) and the truth,
projected on the line-of-sight to the user
2001 SPS Performance Standard (RMS over all SPS
SIS URE)
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5
2008 SPS Performance Standard (Worst of any SPS
SIS URE)
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RMS SIS URE (m)
RMS Signal-in-Space User Range Error (URE), meters
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Decreasing range error
2
1.6
1.2
1.1
1.0
1
0
1990
1992
1994
1996
1997
2001
2004
2006
2008
Selective Availability (SA)
System accuracy exceeds published standard
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L5 Update

• Third civil signal
• Brought Into Use 10 April 2009
• Designed to meet demanding requirements for
  transportation safety-of-life
• Initial broadcast of the L5 demonstration signal
  was monitored and validated

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IIR-20 (M) Update (SVN 49 / PRN 01)

• The GPS IIR-20(M) satellite launched March 24,
  2009 is experiencing out of family measurements
  discovered April 9, 2009
• The United States Air Force has formed a response
  team
• Currently examining data from the satellite that
  is not consistent with other IIR-M satellite
  signal performance
• The response team continues to aggressively work
  to resolve the issue and expects engineering
  analysis to continue for at least two more months
• The teams goal is to thoroughly analyze the data
  to identify root cause and a way ahead
• Worldwide GPS users and the operational
  satellites are not impacted by this problem since
  this satellite is still in the Early Orbit
  Checkout phase and has not been introduced into
  the operational constellation

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Cooperation with other GNSS

• GPS is actively engaged with other GNSS
• To ensure RF compatibility in increasingly
  crowded GNSS bands
• To maximize interoperability through use of
  common civil signals (e.g. L1C)
• Bi-lateral meetings with Galileo, QZSS, GLONASS,
  Compass, IRNSS

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Summary

• GPS has continuously met its commitments to all
  users since FOC in 1995
• GPS has had multiple operational and acquisition
  successes in the past year
• Modernization of all GPS Segments is on track
• Actively working with other GNSS programs

A Commitment of Service
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• Questions?