USM RTK Workshop Fugro Chance Inc. Starfix HP: High Performance GPS For Offshore Marine Survey, Navigation and Positioning Richard Barker, Dr. Dariusz Ł apucha, Tony Wood FUGRO CHANCE INC.

USM RTK Workshop Fugro Chance Inc.Introduction Differential GPS: DGPS: Meter level accuracy over wide area RTK: Centimeter level accuracy over small area Starfix High Performance (HP): Decimeter level accuracy over region using geostationary satellite broadcast Advance of Fugro Starfix Plus Iono free DGPS Service

USM RTK Workshop Fugro Chance Inc. Starfix HP Characteristics High Precision Carrier Phase Measurements  Evaluation of Error Sources  Proprietary Method of DD Ambiguity Resolution Network Solution Long Baseline > 600 km Offshore Regional Service  Target Accuracy  10 cm Horizontal 20 cm Vertical Baseline < 1000 km ITRF 00 Reference 

USM RTK Workshop Fugro Chance Inc. Fundamental HP Measurement 300 m (code)20 cm (phase) Measurement accuracy is 1% of wave length ==> Code < 3 m ==> Phase ~ 2 mm

USM RTK Workshop Fugro Chance Inc. GPS Error Sources Satellite Orbit and Clock Satellite clock and broadcast ephemeris errors are from.5–2m. Orbits to 10m in rare instances Largely removed by DGPS and orbit correctors GPS Signal Multipath (reflections) and Receiver Noise Dependent on receiver type, antenna, and antenna placement.2–5 m Ionosphere  Region of free electrons from 100–1000 km Mitigated with models and measurements 5–45 m Troposphere  The Atmosphere from sea level to 16 km Mitigated with models and measurements 2–20m

USM RTK Workshop Fugro Chance Inc. The Ionosphere

USM RTK Workshop Fugro Chance Inc. Ionospheric Errors The Ionosphere Is a Major Error Source for GPS Users Average daytime ionospheric zenith delay at L1 is 5-15 meters. Can be as much as 36m at equator during solar maximum At 5 degrees elevation, the total delay is about three times the zenith delay The Ionosphere Is a Dispersive Medium Scatters and distorts the GPS signal

USM RTK Workshop Fugro Chance Inc. Current Solar Cycle

USM RTK Workshop Fugro Chance Inc. Regions of Ionospheric Activity

USM RTK Workshop Fugro Chance Inc. Single Frequency Baseline Rio de Janeiro - Recifé 1860km 05/16/00

USM RTK Workshop Fugro Chance Inc. Dual Frequency Baseline Rio de Janeiro - Recifé 1860km 05/16/00

USM RTK Workshop Fugro Chance Inc. Current Solar Cycle

USM RTK Workshop Fugro Chance Inc. Current Kp

USM RTK Workshop Fugro Chance Inc. The Troposphere

USM RTK Workshop Fugro Chance Inc. The Troposphere Troposphere Is Another Major Error Source Tropospheric zenith delay is ~ 2.5 m. Tropospheric mapping functions have a value of about 10 at 5° elevation Troposphere Delay Can Be Separated Into Two Parts, Each With Its Own Mapping Function Hydrostatic (dry) term, f (P,T) Accounts for 80-90% of the total delay Can be predicted with high degree of accuracy Wet term, f (water vapor,T) Highly variable. Significant factor in GOM

USM RTK Workshop Fugro Chance Inc. Starfix-HP Carrier Phase Positioning Based on dual frequency carrier phase Ionospheric elimination Tropospheric estimation Multiple reference stations Virtual base station corrections created on-the- fly Minimizing distance dependent errors Proprietary DD ambiguity resolution method Positioning rate independent on reference update rate High accuracy maintained during short (<60 seconds) reference data outages Robust decimeter accuracy positioning Full QC functionality

USM RTK Workshop Fugro Chance Inc. High Performance Service Introduced in May 2001 in the Gulf of Mexico and the North Sea West Africa South America Europe Persian Gulf Baku Australia South E. Asia Broadcast via geostationary satellites in L-band Complements Starfix and Omnistar positioning services Ongoing expansion of high precision network to support client operations

USM RTK Workshop Fugro Chance Inc. Fugro DGPS Services

USM RTK Workshop Fugro Chance Inc. Fugro Fugro DGPS Services 85 reference stations worldwide Different methods of reference data delivery to Network Control Centers Houston Perth Backup connections ITRF 00 reference worldwide NAD83 in US (Std. Starfix/Omnistar)

USM RTK Workshop Fugro Chance Inc. HP Test Results Static Tests in US and Europe Short (350 km) and Long Baseline (1100 km) Dynamic Operational Testing (Travelogue) Kinematic Position Comparison Heave Comparison (Analog vs. HP) Real-Time Tide vs Computed Gravity (acceleration comparison) Survey Control for Tests JPL Auto GIPSY NGS OPUS SCRIPPS SOPAC ITRF 00

USM RTK Workshop Fugro Chance Inc. GOM Region Short Baseline Testing (350 km)

USM RTK Workshop Fugro Chance Inc. Short Baseline Static Results (Lafayette)

USM RTK Workshop Fugro Chance Inc. Short Baseline Static Results (Houston)

USM RTK Workshop Fugro Chance Inc. Long Baseline Testing (1100 km)

USM RTK Workshop Fugro Chance Inc. Long Baseline Static Results (Lafayette)

USM RTK Workshop Fugro Chance Inc. North Sea Region Static Testing Oslo

USM RTK Workshop Fugro Chance Inc. Oslo Static Results (300 km Baseline)

USM RTK Workshop Fugro Chance Inc. Rogaland Static Results (300 km Baseline)

USM RTK Workshop Fugro Chance Inc. Oslo-Tromso Long Baseline Results (1150 km)

USM RTK Workshop Fugro Chance Inc. GOM Region Dynamic Testing

USM RTK Workshop Fugro Chance Inc. Dynamic Testing

USM RTK Workshop Fugro Chance Inc. Kinematic Reference Location

USM RTK Workshop Fugro Chance Inc. Surprise At The Dock

USM RTK Workshop Fugro Chance Inc. Kinematic Reference Location

USM RTK Workshop Fugro Chance Inc. Vessel Installation

USM RTK Workshop Fugro Chance Inc. Dynamic RTK Test #1

USM RTK Workshop Fugro Chance Inc. Dynamic RTK Test #2

USM RTK Workshop Fugro Chance Inc. North Sea Region Dynamic Testing Oslo

USM RTK Workshop Fugro Chance Inc. UK HP Test Survey Vessel

USM RTK Workshop Fugro Chance Inc. UK HP Test Vessel

USM RTK Workshop Fugro Chance Inc. North Sea HP Test Vessel

USM RTK Workshop Fugro Chance Inc. North Sea Analog Heave vs HP

USM RTK Workshop Fugro Chance Inc. UK Tide Measurement with HP

USM RTK Workshop Fugro Chance Inc. Marine FLCT Gravimeter

USM RTK Workshop Fugro Chance Inc. Gravity vs HP Acceleration Measurements

USM RTK Workshop Fugro Chance Inc. Gravity Measurement Improvement Velocity EÖTVÖS Effect (Inherent in gravity taken on a moving vehicle on a rotating earth) Requires Accurate Course and Speed: +/-deg. +/-knots Eötvös STARFIX.HPG mGal STD. NAV mGal

USM RTK Workshop Fugro Chance Inc. Gravity Measurement Improvement Vertical Sea Level Change Effect (Due to Tides and Weather) Approximately 0.26 mGal/meter of water. Significant Cause of Line Leveling Errors, especially on 3d surveys when accurate tides are not measured.

USM RTK Workshop Fugro Chance Inc. Current Marine Applications Improved vertical accuracy for processing of seismic, gravity, bathymetry, other sensors data Reduced noise for DP vessel positioning Real-time tide corrections Precise relative piling measurements Precise Rig Positioning

USM RTK Workshop Fugro Chance Inc. Precise Relative Pile Installation With HP

USM RTK Workshop Fugro Chance Inc. User Equipment Versions With: Integrated GPS receiver, L-band receiver and processor Supports several dual frequency GPS receiver brands External monitor and keyboard support Multiple output formats

USM RTK Workshop Fugro Chance Inc. Marine Unit SPM2000A.HP Front Panel SPM2000A.HP Back Panel

USM RTK Workshop Fugro Chance Inc. Land Unit

USM RTK Workshop Fugro Chance Inc. Questions ?