Some Thoughts on Satellite Induced Phase Shifts aka "the L2C Quarter Cycle Problem" and the Impact on RINEX and RTCM

This brings back an old issue of phase shifts induced by the satellite for signals on the same carrier. Before L2C signals became available, multiple phase measurements on the same carrier frequency were possible for L1 C/Aand P-Code signals only. Since both signals are available for all satellites a receiver or application could choose one signal for further processing. The RINEX standard did support only one phase for L1. Thus, the phase shift bias was identical for all satellites and could easily be estimated or eliminated through differencing and did not cause serious problems.