Overview of FAA Satellite Navigation Transition and Backup
Overview of FAA Satellite Navigation Transition and Backup Strategies Int’l Loran Association October 28, 2002
Safety First and Foremost Navigation The Separation Safety Triad Communications Surveillance Three Legs of the Safety Stool
Drivers for Transition and Backup Strategy • Workload within interference area • Sustaining separation • Radar • Non-radar • Assuring safe recovery and landing of aircraft in weather • Minimizing disruption of air transportation to reduce threat • Minimum investment for users in backup capability
Issues During an Interference Event • Response time in detecting size of disruption • Will controllers know size of interference area quickly to tactically make adjustments? • How do pilots get the information to make route change decisions? • Controller workload • Pilot workload • Response time to find and shut down interference • Terrain avoidance in interference area in weather • En route low altitude RNAV routes • Terminal maneuvering • Procedural separation in absence of navigation
General Assumptions • Do. D needs continued TACAN/DME/ILS • Precision landing capability (ILS) at least on one runway at those airports necessary for recovery of aircraft during an interference event • All Category II/III ILS systems retained • New runway landing capabilities can be served by ILS, GPS(WAAS) or GPS(LAAS) • Approach lights retained where Category I ILS’s shut off • Sufficient VOR’s retained for VOR-VOR direct navigation and landing with VOR non-precision approach at selected airports (minimum operating network) • DME’s retained to support INS/FMS redundancy • Nav coverage richer where surveillance is limited
Greater navigation infrastructure retained where surveillance coverage is lacking for low altitude operations Lack of Surveillance Coverage Secondary Surveillance Coverage at 6, 000 ft AGL © Mitre CAASD
Instrument Ops Percentages • • Top 200 Airports: 92% of Instrument Ops Top 250 Airports: 95% of Instrument Ops Top 300 Airports: 97% of Instrument Ops Top 350 Airports: 99% of Instrument Ops
Where is aviation on the curve? System Disruption Likelihood of Occurrence Technology Exists ? ? ? ? Threat Scenarios publicly known • Ground emitter • Intermittent emitter • Airborne emitter How much “insurance” is needed to provide critical Infrastructure protection?
Scaled Response Operational Contingency Backup Capability Redundant Capability Procedures VOR Minimum Operating Network Only Long-Range NDB’s ILS DME-DME IRS/FMS ILS Threat Mitigation Intentional Interference Event Operations Disruption
LORAN as a backup Best theoretical Part 91 backup • RNAV backup for RNAV • Integrated antenna with GPS • One sensor in an integrated avionics package • Capable of providing alternative independent path for differential corrections for GPS • Coverage in mountainous terrain for navigation and differential correction for GPS • Reduced number of VOR’s below minimum operating network But….
LORAN X • • • Updated ground infrastructure must continue Not the LORAN C avionics as flown today Loran C only useful for en route nav Existing avionics declining as GPS overtakes panel space in aircraft Must be able to support non-precision approach Meets availability though all-in-view receiver • Each transmitter stick used instead of chains H-field antenna for improved signal-to-noise (p-static) Affordable as card in GPS box, not stand alone receiver Avionics in 5 – 7 years (no MASPS/MOPS or TSO) High market risk even with a DOT decision to continue LORAN C 18, 200 remaining LORAN-C VFR receivers 8, 735 remaining IFR receivers remaining
VOR Proposal for Minimum Operating Network • Victor Airways and Jet Routes begin reduction in 2010 leading to no airways by 2014 • Replaced with VOR-VOR direct aids and Airport VOR aids • Airport VOR supports either VOR NPA, or VOR radial to ILS • Minimum Operational Network of VOR’s attained by 2014 No location in the CONUS further than 75 miles from VOR at 5, 000 feet AGL line-of-sight • Mountainous locations treated differently due to altitude and icing concerns • Replace/relocate MON VOR’s and reduce impact of masking radials from 2007 through 2012
Current VOR Coverage 1008 VOR/VORTAC/VOR-DME Number Visible 5000 ft AGL 0 1 2 © 2002 The MITRE Corporation. All Rights Reserved. >3
VOR Backup Coverage - 429 VOR/ VORTAC/VOR-DME (177 + 252 Fillers) Number Visible 5000 ft AGL 0 1 2 © 2002 The MITRE Corporation. All Rights Reserved. >3
Existing DME Coverage 930 FAA DMEs (VORTAC/VOR-DME) Number Visible 18, 000 ft MSL 0 1 2 © 2002 The MITRE Corporation. All Rights Reserved. >3
671 Airports with at Least One ILS © 2002 The MITRE Corporation. All Rights Reserved.
Redundancy Continue Through Area As Planned Using RNAV 1. 2. 3. 4. 5. 6. 7. 3 2 4 Airport VOR En Route VOR Backup Request Climb or Radar Vector Climb up to 5000’ AGL Proceed Direct to VOR Continue to next VOR Free of Interference Request RNAV and Altitude Change 1 6000’ MSL Interference Area 4000’ MSL VOR 3 5000 AGL 4000’ MSL 1000’ MSL Ground Level VOR 1
Likely Civil User Equipage (En Route Through Non-precision Approach) Add Current Avionics Satnav Retain Ground-based Navigation Backup FMS with inertial GPS/inertial (or GPS/WAAS) FMS (DME/DME or inertial) RNP/RNAV FMS No inertial GPS (or GPS/WAAS) FMS (DME/DME) RNP/RNAV No FMS or inertial GPS/WAAS (1) VOR or (2) Loran RNAV or (3) Ops Contingency
Likely User Equipage (Precision Approach) Add Current Operations Scheduled Operations Large Airports Scheduled Operations Many Airports Unscheduled Operations Many Airports Satnav GPS/LAAS 200 feet and ½ mile GPS/WAAS 250 feet and ½ mile with approach lights GPS/WAAS 250 feet and ¾ mile without approach lights Retain Ground-based Navigation Backup ILS Cat I/II/III ILS/Cat I 200 feet and ½ mile (1) ILS/Cat I or (2) Ops Contingency
02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 1, 033 VOR 1, 168 ILS – CAT I and Localizer Only Retain on at least one runway 117 20 Minimum Operating Network ILS – CAT II/III Current runways retained for capacity GPS III GPS > 500 > 546 > 125 L 5 Usable > WAAS - 250 ft & ¾ mile vis (LPV) 3 rd GEO > WAAS - GLS LAAS CAT I 6 airports + options for 0 to 40 per year LAAS CAT II/III 878 596 R&D Required DME (VOR/DME and Stand Alone) TACAN (includes DME) Long Range NDB – Alaska and Coastal LORAN ? ? ? Decision on Continued Use In Late 2002 > 930 596
Instrument Approaches and WAAS • The intent of WAAS was to provide three levels of service for instrument approaches: – GLS (GPS Landing System) • Equivalent of ILS • Requires 40 m HAL and 12 m VAL • Requires LAAS – LNAV/VNAV(Lateral/Vertical Navigation) • Requires 556 m HAL and 50 m VAL • Requires WAAS or Baro/VNAV (GPS or DME/DME and Baro) – LNAV (Lateral Navigation) • Requires 556 m HAL – No vertical guidance (non-precision approach) • Requires GPS, WAAS, or DME/DME LNAV • New capability from GPS/WAAS – LPV (Lateral Precision with Vertical Guidance) • Realizes a 40 m HAL and 50 m VAL • Provides lower minimums at more runway ends • Requires WAAS
Horizontal and Vertical Protection Required V H LNAV/VNAV - RNP. 3 (556 m horizontal by 50 m vertical) LPV (40 m horizontal by 50 m vertical) GLS (40 m horizontal by 12 m vertical) Full GPS Landing Systems (GLS) will be available from LAAS and when the new L 5 radio frequency is operational from the GPS satellite constellation
3500 3000 2500 2000 LNAV/VNAV LPV 02 25 58 932 32 7 839 39 5 64 46 65 653 53 4 560 60 3 474 0 M or O bs e ta A cle pp s ro Pr ac ev h en t 1500 1000 500 0 25 Number of Runways LPV and LNAV/VNAV Height above Touchdown (HAT) HAT (ft) 5073 runway ends at 1534 airports © 2002 The MITRE Corporation. All Rights Reserved.
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