Federal Aviation Administration Alternative Positioning Navigation Timing APNT

Federal Aviation Administration Alternative Positioning, Navigation & Timing (APNT) Study Update Leo Eldredge October 14, 2010

Why APNT? • The transformation of the National Airspace System (NAS) to the Next Generation Air Transportation System (Next. Gen) relies on GPS-Based PNT services and suitable alternate PNT services – – – Current ATC system cannot be scaled up to handle 2 X traffic is more than a controller can handle using radar vectors RNAV and RNP procedures for trajectory-based operations (TBO) Automation will separate aircraft performing trajectory based operations (TBO) Controllers intercede to provide “control by exception” • TBO Operations may require PNT performance that exceeds DME/IRU • GPS vulnerability to radio frequency interference (RFI) requires mitigation – Waiting for the source of the interference to be located and turned off is not an acceptable alternative APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 2

Baseline Airspace Condition • En Route • Sector • Ghost • 01 • (BAASS) • Sector • (not depicted) • Terminal • Sector • D • En Route • Sector • 02 (GRUPR) • Terminal Enabled by Legacy NAVAIDs • VOR/DME, VORTAC, NDB • Sector • A • Point-to-Point Navigation APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 3

• Arrival Transition Sector • Dynamic Airspace Big Airspace Concept • 1 • Ghost • Sector • 01 • (BAASS) • Dynamic Airspace • 2 • Airport Departure • Departure Transition • Sector - D • Sector • D • 02 (GRUPR) • D • Feeder • Sector - A Enabled by PBN • GPS, WAAS, LAAS, DDI • Area Navigation (RNAV) • Required Navigation Performance (RNP) APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 4

TBO 3 -Mile Separation with RNP 3 Mile Separation DME / IRU Performance Limit RNP-1. 0 1 nm Overlap 2 x RNP 1. 0 TBO (APNT) Requirement 2 x RNP 0. 3 Primary PNT Service: GPS meets all TBO requirements Alternate PNT Service: DME/IRU won’t support 3 NM separation APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 5

GNSS Enables PBN and ADS-B APNT Navigation (> 99. 0% Availability) En Route Terminal Accuracy (95%) Containment (10 -7) *10 nm 20 nm *4 nm 8 nm *2 nm 4 nm *1 nm 2 nm LNAV *0. 3 nm 0. 6 nm RNP (AR) *0. 1 nm **0. 1 nm LPV 16 m/4 m 40 m/50 m LPV-200 16 m/4 m 40 m/35 m GLS Cat-I 16 m/4 m 40 m/10 m GLS Cat-III 16 m/2 m 40 m/10 m Surveillance (>99. 9% Availability) Positioning Separation NACp (95%) NIC (10 -7) GNSS PNT (99. 0 – 99. 999%) 5 nm 308 m (7) 1 nm (5) GPS 3 nm 171 m (8) 0. 6 nm (6) DME Only Gap 2. 5 nm DPA 171 m (8) 0. 2 nm (7) 2. 0 nm IPA 121 m (8) 0. 2 nm (7) SBAS GBAS * Operational requirements are defined for total system accuracy, which is dominated by fight technical error. Position accuracy for these operations is negligible. ** Containment for RNP AR is specified as a total system requirement; value representative of current approvals. Dependent Parallel Approach (DPA) Independent Parallel Approach (IPA) Surveillance Integrity Level (SIL) Navigation Integrity Category (NIC) Navigation Accuracy Category for Position (NACp)

PNT Performance Zones FL-600 Zone- 1 Enroute High CONUS FL-180 Zone- 2 Enroute Low CONUS Zone-3 Terminal 5000’ AGL OEPs + Next 100 Busiest Airports 2° Slope from 500’ AGL 5 SM of Airport 27 SM APNT Study Brief to PNT Advisory Board October 14, 2010 89 SM Federal Aviation Administration 7

Zone 1, 2, and 3 Geographic Areas APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 8

GNSS Challenges: GPS Testing by DOD • Geographical Area Impacted 9 Month Duration • 141 • NOTAMs 141 NOTAMs • Maximum • Miles 2 • 2 Miles • Minimum 2 • Miles • 2 Miles • Average 2 • Miles • 2 Miles • Shortest • 1. 0 hour • 455, 805 • 66, 018 • 139, 795 • Average • 6. 63 hours • Longest • 72 hours • Cumulative • 782 Hours • 90 days Federal Aviation Administration 9 APNT Study Brief to PNT Advisory Board October 14, 2010

Commercially Available GPS Jammer (so called “Personal Privacy Device”) APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 10

LAAS Antenna Location APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 11

Zeta “Snap. Shot” System Data • Baseline/Nominal L 1 RF APNT Study Brief to PNT Advisory Board October 14, 2010 • Broadband RFI straddling L 1 Federal Aviation Administration 12

… and a few more “Personal Privacy Devices” $110 Ebay $40 GPS&GSM www. chinavasion. com APNT Study Brief to PNT Advisory Board October 14, 2010 $92 Ebay $335 Ebay $55 Ebay $83 GPS&GSM www. Tayx. co. uk Federal Aviation Administration $152 Ebay 13

RFI Challenges without APNT • Transitioning from 3 -mile to 5 -mile separation en route and on arrivals outside of 40 nm when a GPS RFI event occurs • Shifting some aircraft to radar vectors – significant implications • Rerouting aircraft around interference area to reduce demand • Throttle back demand to compensate for loss of capabilities like parallel runway approaches • Limit RNAV/RNP arrivals and departures and reduce options to handling arrivals APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 14

APNT Alternative 1 Optimized DME Network APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 15

1100 DMEs in Current Nework APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 16

DME-DME Alternative • Strengths – Leverage existing technology and systems – Least Impact on Avionics for Air Carriers • Weaknesses – General Aviation generally does not equip with DME – DME-DME equipped aircraft without Inertial are not currently authorized to fly RNAV/RNP routes – DME-DME, even with Inertial, is not authorized for pubic approach operations less than RNAV/RNP-1. 0 – DME-DME interrogations saturate in very high traffic environments – Will require retention and capitalization of nearly half the VORs unless GA equipped with DME/DME inertial APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 17

APNT Alternative 2 Wide Area Multi-Lateration APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 18

Passive Wide-Area Multi-Lateration (WAM) 1 –Aircraft Transmits ADS-B Signal 6 – Aircraft Uses Own Position for Navigation 5 - TIS-B Sends Position to Aircraft Combined DME/GBT Network 2 - WAM Receives Signal 3 - Aircraft Position Determined 4 - Aircraft Position Sent to GBT’s APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 19

656 GBT’s for National Coverage Communication Coverage: Not Navigation APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 20

Combined Network of DMEs and GBTs APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 21

Approaches Histogram Nav. Canada Independent Verification Of Data Instrument Procedures APNT Study Brief to PNT Advisory Board October 14, 2010 Meters Feet Average 9. 4 30. 8 Max 81. 3 266. 9 Min 0. 0 Median 8. 0 26. 1 Std. dev 8. 0 26. 3 1 -sigma 11. 0 36. 1 2 -sigma 23. 0 75. 5 Federal Aviation Administration 22

MLAT Alternative • Strengths – Accuracy Demonstrated to be within target levels – Compatible with existing WAM Systems • Weaknesses – – – Throughput on 1090 ES may limit availability Minimum of 3 sites required to compute aircraft position Integrity monitoring and Time to Alert may be challenging More sites may be needed due to limited signal range Requires a GPS-Independent common time reference Significant investment in processing facilities and terrestrial communications network may be required – Use of MLAT for Navigation will require avionics changes APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 23

APNT Alternative 3 DME Pseudolites (DMPL) APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 24

Pseudolite Alternative Concept • Aircraft Calculates Position • RAIM Based Integrity Solution • Combined Network of DME/GBTs etc • GPS-Independent Time Reference • 1 Hz Message ID and Time @ Transmit • PNT Data Broadcast Channel APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 25

Pseudolite Alternative • Strengths – – – Unlimited capacity Less complexity for ground-based system Potential for aircraft based integrity solution Potential to leverage use of existing DMEs and GBTs Potential to uplink data other navigation data to aircraft • Weaknesses – Minimum of 3 sites required to compute aircraft position – Significant investment in processing facilities and terrestrial communications network may be required – Common GPS-independent timing reference needed – Greatest Impact to Aircraft Avionics – Least mature concept, no standards exist APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 26

APNT Timing Service APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 27

Ground-to-Ground Time Synchronization GEO: WAAS L 5 MEO: GNSS LEO: MSS 30 d. B of processing gain DMEs + Planned DMEs + GBTs APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 28

WAAS L 5 for Ground-to-Ground Synch. STAP J/S = 45 d. B APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 29

Summary • Next. Gen Operational Improvements enabled by performance based navigation capabilities increases dependence on GPS and alternate PNT services • GPS vulnerability to radio frequency interference needs to be addressed for trajectory based operations at some locations • Alternatives are being studied for further consideration APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 30

Questions APNT Study Brief to PNT Advisory Board October 14, 2010 Federal Aviation Administration 31