Studies up until the early 2000s mainly focused on variations in broadcast ephemeris accuracy. Since the mid-
2000s, they have focused on broadcast ephemeris fault detection and statistics. GPS broadcast ephemeris accuracy in
1999 and 2000 was analyzed by Langley et al. [3]. Warren and Raquet analyzed the variation of GPS broadcast
ephemeris errors over a decade (1993-2002) [4]. Daily and yearly GPS and GLONASS broadcast orbit errors from
1994 to 2003 were analyzed by Starr et al. [5]. Also, broadcast ephemeris errors according to GPS blocks and
shadow conditions were analyzed. The geographical variation of pseudorange error was investigated. Cohenour and
Graas discussed GPS signal-in-space (SIS) fault probabilities and error distributions from 2005 to 2012 [6].
Montenbruck et al. analyzed the phase center offset (PCO) of GPS and GNSS satellites [7]. The satellite broadcast
errors of 2013 were analyzed