JPL DESCANSO - Deep Space Communications and Navigation Center of Excellence

JPL's Global Differential GPS Technology: Past, Present, and Future

Presented by:
Dr. William Bertiger
Principal Engineer
Tracking Systems and Applications Section 335


From its inception five years ago, JPL's differential Global Positioning System (GPS) has defined the state-of-the-art technology. Technology transfers have had significant impact on the nation's aviation infrastructure and on the commercial market for GPS differential corrections. Recent internet-based innovations promise to propel the technology to a new level of utility, providing the world's first global differential GPS service, with unparalleled accuracy, coverage, and economy. The new technology, termed Global Differential GPS (GDGPS), is capable of providing suitably-equipped users with 20 cm accurate real time positioning, anywhere, anytime. This level of performance is at least an order of magnitude better than available with operational GPS, or with any commercial or governmental differential service. For users with modelable dynamics, such as Earth satellites, orbit determination techniques can improve the accuracy to well below 10 cm in real time. This level of positioning accuracy was previously possible only with post-processing of data days after the fact.

A NASA global differential service can reduce costs and/or enable projects such as remote sensing from earth orbit and natural hazard monitoring (earthquakes, volcanoes, rapid changes in troposphere). Much of the technology carries over to systems that could be used at Mars and other planets.

The Speaker

Dr. Willy Bertiger received his Ph.D. in Mathematics from UC Berkeley in 1976. He taught at Texas A&M University and did research at Chevron before joining JPL in 1985. At JPL, Willy focused on GPS techniques and applications. As a principal engineer, Willy has been a key member in a number of projects where GPS is a critical element, including Topex/Poseidon, the recent Shuttle Radar Topograph Mission (SRTM), and WAAS, the FAA's aircraft navigation system.