Patent ID: 8514128

Claim:
An extended ephemeris satellite navigation receiver for receiving microwave transmissions from orbiting navigation system satellites, and for demodulating navigation messages that include the ephemerides for those navigation system satellites, comprising: storage for storing a force model modeling accelerations acting on multiple different satellite vehicles (SV), in accordance with which a single observation of the ephemeris for an SV is input and propagated days into the future by integrating that SV's orbital position with its corresponding force model; a processor for processing ephemeris observations in accordance with the force model to obtain extended ephemeris predictions that can be used as substitutes when said navigation messages from respective SVs cannot otherwise be immediately obtained and demodulated; a Keplerian solver program for execution by the processor that receives a series of future predicted X-Y-Z type SV position samples in an earth-centered, earth-fixed (ECEF) coordinate system and thereafter computes estimates for the Keplerian parameters {right arrow over (X)}=[a, e, i0, M0, Δn, di/dt, ω, Ω0, {dot over (ω)}, Crs, Crc, Cus, Cuc, Cis, Cic] or a subset thereof that fit the series of X-Y-Z type SV position samples; wherein the processor is configured to store in local memory satellite models derived from the estimates for the Keplerian parameters, the satellite models comprising satellite models for a plurality of future days, further comprising a plurality of satellite models for each of said days.