http://www.ncgia.ucsb.edu/education/curricula/giscc/units/u017/figures/figure07.gif

 

 

http://www.ncgia.ucsb.edu/education/curricula/giscc/units/u017/figures/figure08.gif

Factory start: No almanac data. Up to 12.5 minutes.

 

 

AEP: Caltech, Embedded Autonomous Ephemeris Prediction Software, GPS/GLONASS, AEP predicts the GNSS orbit and clock states nearly as well as JPL's network-based AGPS product. 7-th day orbit and clock prediction accuracy = 15m user range error