Aircraft Landing Systems Based on GPS & Galileo

Aircraft Landing Systems Based on GPS & Galileo for the Czech Technical University by Per Enge Thursday 4 August, 2005

Future Aircraft Landing Systems: Outline 1. Today: Global Positioning System (GPS) & Augmentations 2. Tomorrow: Modernized GPS & Galileo New signals Category I from SBAS & Galileo 3. Continued Need for the Local Element Category II/III Unexploded ordinance 4. Continuity Will be Key! Antennas Inertial Navigation

Global Positioning System Space Segment Uplink Ephemeris & Clock Data Broadcast of Navigation data Spread-spectrum ranging signals Control Segment 60,000,000 users?? Five Monitor Stations & Four Upload Stations Spread Around the Equator

GPS Receiver Bazaar by Frank Van Diggelen, GlobalLocate Survey & Mapping Original civil application Tripod mounted Exclusively Differential GPS One meter to centimeter accuracy $2500-$40,000 Chip sets/single chip GPS $5-$20 Lowest prices from sharing the host CPU

Receiver Bazaar (cont d) Handheld receivers For hikers, geo-cachers & sailors. Small in size with simple maps. Ruggedized for outdoor/marine use. $70-$500 GPS cell-phones with GPS embedded. In 2004, 50% of GPS receivers are in cell phones. Mostly for emergency calls only. LBS applications are emerging. $200-$500

Receiver Bazaar (cont d) GPS smart-phones (cell phone + PDA) GPS is embedded. GPS used for emergency calls Applications include: basic maps spoken turn-by-turn directions $400-$800 Dedicated in-car navigation systems. Detailed street maps Spoken turn-by-turn directions $400-$2000

Receiver Bazaar (cont d) OEM boards Enables custom integration $30-$100 Marine navigation Large screens Electronic charts Sophisticated nav. functions Large marine data bases. $400-$3000

GPS constellation Differential GPS Data broadcast of corrections Reference receiver(s) compare measured pseudoranges to theoranges. Roving receivers apply corrections to measured pseudoranges

Differential GPS Radiobeacons Around the World Ref: CSI, Inc.

Space Based Augmentation System (SBAS) Wide Area Augmentation System (WAAS) in the U.S. GPS constellation Geostationary broadcast of 1.) Continental corrections 2.) Data for error bounds 3.) Ranging signal Uplink station Reference receivers Central processor

SBAS Reference Stations in the U.S.

Aviation Receivers Air Transport multi-mode receiver GBAS/ILS/MLS General aviation panel mounted with maps SBAS/VOR/DME VHF voice

SBAS Enables Precision Approach Down to 300 Feet APV DH=350 DH VAL=50 m DH: decision height VAL:vertical alert limit LAL: horizontal alert limit APV: approach with vertical guidance

Typical WAAS Vertical Error and VPL

WAAS Vertical Error & VPL on a Storm Day

GPS Signals: Present and Future Today s satellites Military C A Military 1207 1227 1247 1555 1575 1595 New satellites launched beginning in 2005 RC Military C A Military New satellites launched near the end of the decade L5 1207 1227 1247 RC Military 1555 1575 1595 C A Military 1156 1176 1196 1207 1227 1247 1555 1575 1595

Galileo E5/A GNSS Spectrum Galileo E5/B GPS L2 Glonass G2 Galileo E6 GPS L1 Glonass G2 1151MHz 1164MHz 1188MHz 1214MHz 1215MHz 1237MHz 1239MHz 1254MHz 1258MHz 1260MHz 1261MHz 1300MHz 1559MHz 1563MHz 1587MHz 1591MHz 1593MHz 1610MHz 5010MHz 5030MHz 5250MHz ARNS RNSS ARNS ARNS RNSS* RNSS* RNSS RNSS Galileo C1 960MHz Galileo E3 GPS L5 Lower L-Band Upper L-Band C-Band Galileo E4 Galileo E2 Galileo E1 RNSS* shared with other services Galileo E5/A or E5/B frequency band options

SBAS With Dual Frequency GPS & Galileo Will Enable Precision Approach Down to 200 Feet APV DH=350 DH VAL=50 m CAT I DH=200 ft VAL=10 m DH: decision height VAL:vertical alert limit LAL: horizontal alert limit APV: approach with vertical guidance

Precision Approach APV DH=350 DH VAL=50 m CAT I DH=200 ft VAL=10 m Local element required: Ground Based Augmentation System Local Area Augmentation System CAT II DH=100 ft VAL=5.3 m CAT III DH=0-100 ft VAL=5.3 m DH: decision height VAL:vertical alert limit LAL: horizontal alert limit APV: approach with vertical guidance

Ground Based Augmentation System (GBAS) GPS constellation VHF data broadcast of airport corrections data for error bounding Airport Property Multiple GPS receivers used for cross-checking & redundancy Central processor to generate corrections & error bounding data

Other Applications for the Local Element Disarm Unexploded Ordinance (UXO) In the U.S. alone, UXO is spread over 10 million acres at 1400 sites. Current DoD budget is $200M/year.

Search for Unexploded Ordinance at Camp Bonneville Centimeter accuracy under foliage requires the integration of DGPS & aiding technology

Prototype of Dual Radiation Pattern Antenna (from Frank Bauregger)

Theoretical Radiation Patterns Wide-looking Patch Narrow-looking Patch - Roll Pattern for Antenna Mounted on Cessna Caravan

Flight Results for DRPA (from Bauregger)

Multi-Element Antennas source beam Reject RFI & multipath Achieve sub-meter accuracy Limit biases in carrier phase and code phase null RFI 1 weight & shift 0.8 0.6 0.4 0.2 0-0.2-0.4-0.6-0.8-1 0 0.5 1 1.5 2 2.5

Inertial Measurements to Aid GPS Tracking (Jennifer Gautier) IMU 3 gyros 3 accels θ, v Navigation Processor P,V, A,T Kalman Filter GPS Receiver Measurement Processor ρ,ρdot Navigation Processor P,V,T Deeply Loosely Tightly Integrated Coupled System or Ultra Tightly Coupled System

INS/GPS Hybrid for LAAS CAT III RFI Final Approach Fix Ground Facility with VHF Data Broadcast Final Approach Segment: 9 km INS navigation w/ or w/o GPS Intermediate Approach Segment: Inertial Calibration with CDGPS

One Dimensional Error Growth for Tactical and Automotive Inertial Navigation Systems 1000 1D Pos. Error For White & Gauss-Markov Noise Only Auto. Acc & GyroØ Position E rro rhml 100 10 1 rate-aid PLL Auto. Acc OnlyØ from FAF Tactical Acc & Gyro Tactical Acc Only fly across terminal area 10 20 50 100 200 500 1000 2000 Time HsL

Stanford Center for Navigation & Time Navigation & time technology will benefit billions of people, millions of businesses, & most nations in a life altering manner in the next 20 years much as is the Internet Although the design of GPS in 1973 began this technology revolution, this technology is just in its infancy. Stanford University Departments in AA, EE, ME, and Physics are each contributing exciting, novel new technologies, and together can play a leading role in this technology revolution which necessarily crosses many department boundaries

Atom-based Inertial Sensors to Deliver 5 m/hour (from Mark Kasevich) Laser cooled atoms are sensor proof masses. Atoms are in a near perfect inertial frame of reference. Pulses of laser light measure relative motion between atoms and case. Sensor accuracy derives from the use of optical wavefronts to determine this relative motion. Field-ready cold atom accelerometer. Demonstrated 10-9 g bias stability

Atom Sensors Technology Vision for Full IMU (from Mark Kasevich) 50 m/hour 3 cm x 3 cm x 1 cm Low-power (10 mw) 100 mdeg/hr 1/2 ARW 10-7 g/hz 1/2 accel noise 100 Hz bandwidth

Build MEMS resonator and encapsulation at same time. Use only CMOS compatible process steps. Resulting resonators are stable, inexpensive, small Wafer Scale Silicon Oscillators (from Tom Kenney) Goal --2 orders of magnitude stability improvement over quartz oscillators

Summary: Vector Delay Lock Loop (from Jim Spilker) satellite navigation signals Generalized Vector Delay Lock Tracking Navigation System `` ` ` Cordinate translator Kalman Filter ` ` ` ` beam steering antenna clock IMU parallel correlator bank chip scale atomic clock generalized Kalman filter atomic inertial measurement units Integration of RF satellite, inertial, and clock sensors into one quasi-optimal Navigation, Attitude, Time estimator