GPS L5

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GPS L5

• Dr. Chris Hegarty
• L2/L5 Industry Day
• May 2, 2001

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Background

• 1996 - GPS Presidential Decision Directive (PDD)
• Comprehensive national policy on GPS and
  augmentations
• Interagency GPS Executive Board (IGEB)
  established
• February 1997 - Department of Defense (DoD) and
  Department of Transportation (DoT) agree to
  provide a second civil GPS frequency
• March 1998 - VP Gore announces IGEB decision to
  implement two new civil signals
• January 1999 - VP Gore announces third civil
  signal frequency selection - 1176.45 MHz

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Background (continued)

• February 1999 - IGEB Third Civil Signal
  Implementation Steering Group formed
• Established relationship between IGEB and RTCA
  for development of L5 signal requirements
• November 1999 - IGEB report Implementation of a
  Third Civil GPS Signal completed
• Recommended implementing L5 with
• 6 dB higher minimum received signal power than L1
  C/A code
• 10.23 Mchip/second spreading codes on quadrature
  channels (no data on one channel)
• Other recommendations regarding coexistence of L5
  with existing systems operating at/near 1176.45
  MHz
• Link 16
• Distance Measuring Equipment (DME)/Tactical Air
  Navigation (TACAN)

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Feb. - Nov. 99 IGEB Organization
Interagency GPS Executive Board (IGEB)
Executive Secretariat
Third GPS Signal Implementation Steering Group
WG 2
WG 3
WG 4
WG 1
Technical Feasibility of Coexistence
Cost Issues/ Operational Impacts
Signal Requirements
International Coordination
GPS WP8D
GPS International Outreach Group
RTCA, Inc (SC 159 WG1)
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Current IGEB L5 Activities

• Working Group 1 -Validation of Coexistence
• Addresses follow-on work recommendations from
  Nov. 1999 IGEB report
• Co-chaired by Dr. Hegarty (MITRE)/Mr. Williams
  (JSC)
• Working Group 2 L5 Signal Specification
• Chaired by Dr. Hegarty (MITRE)

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Present IGEB Organization
Interagency GPS Executive Board (IGEB)
Senior Steering Group
Executive Secretariat
WG 1
WG 2
Validation of Coexistence
Signal Specification
RTCA, Inc (SC 159 WG1)
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L5 Signal Specification Schedule

• December 2000
• RTCA Program Management Committee (PMC) approved
  L5 Signal Specification
• Received formal civil coordination through the
  extended DOT Positioning/Navigation Executive
  Committee, with all agencies concurring
• February 2001 - DoD review completed and comments
  provided to DOT
• April 2001 - DOT response to comments
• October 2001 - Threshold date for 1st release of
  Interface Control Document (ICD) GPS-705