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

APNT Study Brief to PNT Advisory Board 2 Federal Aviation Administration October 14, 2010 Why APNT? The transformation of the National Airspace System (NAS) to the Next Generation Air Transportation System (NextGen) relies on GPS-Based PNT services and suitable alternate PNT services –Current ATC system cannot be scaled up to handle 2X traffic –2X 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/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 3 Federal Aviation Administration October 14, 2010 Terminal Sector D Ghost Sector (not depicted) Terminal Sector A En Route Sector 02 (GRUPR) En Route Sector 01 (BAASS) Baseline Airspace Condition Enabled by Legacy NAVAIDs VOR/DME, VORTAC, NDB Point-to-Point Navigation

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

APNT Study Brief to PNT Advisory Board 5 Federal Aviation Administration October 14, 2010 TBO 3-Mile Separation with RNP 1 nm Overlap 2 x RNP 0.3 DME / DME / IRU Performance Limit RNP x RNP Mile Separation TBO (APNT) Requirement Primary PNT Service: GPS meets all TBO requirements Alternate PNT Service: DME/DME/IRU won’t support 3 NM separation

Navigation (> 99.0% Availability) Surveillance (>99.9% Availability) Positioning Accuracy (95%) Containment (10 -7 ) Separation NACp (95%) NIC (10 -7 ) GNSS PNT (99.0 – %) En Route *10 nm20 nm 5 nm 308m (7) 1 nm (5) GPS *4 nm8 nm *2 nm4 nm Terminal*1 nm2 nm 3 nm 171m (8) 0.6 nm (6) LNAV*0.3 nm0.6 nm RNP (AR)*0.1 nm**0.1 nm 2.5 nm DPA 171m (8) 0.2 nm (7) SBAS LPV16m/4m40m/50m 2.5 nm DPA 171m (8) 0.2 nm (7) LPV-20016m/4m40m/35m GLS Cat-I16m/4m40m/10m 2.0 nm IPA 121 m (8) 0.2 nm (7) GBAS GLS Cat-III16m/2m40m/10m GNSS Enables PBN and ADS-B Dependent Parallel Approach (DPA) Independent Parallel Approach (IPA) Surveillance Integrity Level (SIL) Navigation Integrity Category (NIC) Navigation Accuracy Category for Position (NACp) * 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. APNT 3 nm 171m (8) 0.6 nm (6) DME Only Gap LNAV*0.3 nm0.6 nm

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

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

APNT Study Brief to PNT Advisory Board 9 Federal Aviation Administration October 14, 2010 GNSS Challenges: GPS Testing by DOD 139,79566,018455,805 Geographical Area Impacted Maximum Miles 2 Minimum Miles 2 Average Miles 2 139,79566,018455,805 Geographical Area Impacted Maximum Miles 2 Minimum Miles 2 Average Miles Hours 90 days Cumulative Duration 141NOTAMs Shortest1.0 hour Average6.63 hours Longest72 hours 782 Hours 90 days Cumulative 9 Month Duration 141NOTAMs Shortest1.0 hour Average6.63 hours Longest72 hours

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

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

APNT Study Brief to PNT Advisory Board 12 Federal Aviation Administration October 14, 2010 Zeta “SnapShot” System Data Baseline/Nominal L1 RF Broadband RFI straddling L1

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

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

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

APNT Study Brief to PNT Advisory Board 17 Federal Aviation Administration October 14, 2010 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 18 Federal Aviation Administration October 14, 2010 APNT Alternative 2 Wide Area Multi-Lateration

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

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

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

APNT Study Brief to PNT Advisory Board 22 Federal Aviation Administration October 14, 2010 Approaches Histogram NavCanada Independent Verification Of Data Instrument Procedures MetersFeet Average Max Min0.0 Median Std. dev sigma sigma

APNT Study Brief to PNT Advisory Board 23 Federal Aviation Administration October 14, 2010 MLAT Alternative Strengths –Accuracy Demonstrated to be within target levels –Compatible with existing WAM Systems Weaknesses –Throughput on 1090ES 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 24 Federal Aviation Administration October 14, 2010 APNT Alternative 3 DME Pseudolites (DMPL)

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

APNT Study Brief to PNT Advisory Board 26 Federal Aviation Administration October 14, 2010 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 27 Federal Aviation Administration October 14, 2010 APNT Timing Service

APNT Study Brief to PNT Advisory Board 28 Federal Aviation Administration October 14, 2010 DMEs + Planned DMEs + GBTs Ground-to-Ground Time Synchronization 30 dB of processing gain GEO: WAAS L5 MEO: GNSS LEO: MSS

APNT Study Brief to PNT Advisory Board 29 Federal Aviation Administration October 14, 2010 WAAS L5 for Ground-to-Ground Synch. J/S = 45 dB STAP

APNT Study Brief to PNT Advisory Board 30 Federal Aviation Administration October 14, 2010 Summary NextGen 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 31 Federal Aviation Administration October 14, 2010 Questions