PROBLEM TO BE SOLVED: To provide a distributed orbit and propagation method for use in a predicted GPS or GNSS system, which includes a predicted GPS server, a source of high accuracy orbit predictions, a global reference network providing real-time GPS or GNSS assistance data to the PGPS server, a predicted GPS client running on a device equipped with a GPS or AGPS chipset.SOLUTION: In response to requests from a PGPS client, a PGPS server produces and disseminates an initial seed dataset consisting of current satellite orbit state vectors and orbit propagation model coefficients. This seed dataset enables the PGPS client to locally predict and propagate satellite orbits to a desired future time. This predictive assistance in turn helps accelerate the time to first fix, optimize position solution calculations and improve sensitivity of a GPS chip present on, or coupled with, a device.
