Task Force

1

• Task Force
• On
• The Future of the Global Positioning System
• (extract)

2
National PNT Objectives

• Provide uninterrupted availability of
  positioning, navigation, and timing services
• Meet growing national, homeland, economic
  security, and civil requirements, and scientific
  and commercial demands
• Remain the pre-eminent military space-based
  positioning, navigation, and timing service
• Continue to provide civil services that exceed or
  are competitive with foreign civil space-based
  positioning, navigation, and timing services and
  augmentation systems
• Remain essential components of internationally
  accepted positioning, navigation, and timing
  services
• Promote U.S. technological leadership in
  applications involving space-based positioning,
  navigation, and timing services

Source U.S. Space-based Positioning,
Navigation, and Timing Policy, NSPD Signed by
President Bush, 15 December 2004
3
Salient Points from Task Force

• The service provided to users is crucialnot
  sub-optimizing the satellite component
• GPS is a system-of-systems. Satellites,
  operational control segment receivers must be
  effectively integrated
• Minimum constellation size should be 30
  satellitesto better support ground forces in
  varied terrain
• Ambitious requirements are driving the cost of
  GPS III
• Cost weight must be controlled
• Dual launch essential
• Relax emphasis on anti-spoof. Increase attention
  to anti-jam
• Time attention must be given to maintain GPS as
  worlds premier satellite navigation.
• Governance needs adjustment improvementopen-min
  ded approach is necessary in considering options

4
Mask Angle Effects
(24-4)
(24-3)
(24-5)
(30-1)
(24-2)
(24-6)
(24-1)
X
X
15o
15o
5o
5o
Assumes 1 m User Range Error Differences caused
by Geometric Dilution of Precision effects (DOP x
URE Accuracy)
5
GPS III Launch Costs
EELV Costs EELV-L75M EELV-M90M
EELV-H150M (Buy 1) EELV-L150M
EELV-M180M EELV-H300M (Buy 3 in Source
Selection) Failure Rates 4 Single 5
Dual (Source GPS JPO Study, 20 Jul 05)