StarFire: A Global High Accuracy Differential GPS System Ron Hatch, Tenny Sharpe, Paul Galyean NavCom Technology Inc. Presented by Jose Romero-Mariona ICS 280 Winter 2006

What is StarFire? Developed by NavCom Technology, Inc. and Ag Management Solutions, both components of John Deere and Company Provides high accuracy navigation with sub-decimeter horizontal accuracy almost anywhere in the world Made possible by various characteristics Development of high quality, dual frequency GPS receivers for use as both reference and mobile receivers, Dual frequency extended smoothing of the code with the carrier to remove the two largest error sources, i.e., ionospheric refraction and multipath effects, Development of a new L-band communication module and associated multi-band antenna

StarFire in Details StarFire evolved from being a set of regional DGPS networks to a global network offering unprecedented accuracy. Seven major components of StarFire Reference Network – reference receivers that continuously provide the raw GPS observables to the Hubs for processing. Processing Hubs – facilities at which the GPS observables are processed into DGPS corrections. Communication Links – provide reliable transport mechanisms for the GPS observables and for the computed corrections. Land Earth Stations – satellite uplink facilities that send the correction data received from the Hubs to the geostationary satellites. Geostationary Satellites – used to distribute the corrections to users via L- band broadcasts. Monitors – user receivers distributed throughout the world that use the broadcast corrections and provide their navigation information to the Hubs in real time. User Equipment – uses the broadcast corrections along with local GPS observables to produce very precise navigation.

StarFire at Work

StarFire’s Positioning Accuracy The real time global accuracy of StarFire is unprecedented. StarFire’s Performance in Australia StarFire’s Performance in USA

StarFire Applications, Present and Future The Starfire system was originally developed by John Deere for agricultural applications, including yield mapping, field documentation, operator assisted steering, automatic steering. The characteristics of StarFire can prove useful in many other applications, including: Land survey and geodesy Geographic Information Systems (GIS) Utility mapping and real time asset location Construction equipment guidance and control Marine survey and resource exploration Aerial Photogrammetry Geophysical land seismic exploration Automated maritime docking

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