One SYS / PHASE SHIFT header record, as the header holds it.
system- the constellation letter, such as"G".code- the carrier observable code, such as"L1C", ornilfor a record naming only its constellation. RINEX 3.05 section 5.2.12 leaves the code and the rest of the record blank where "the applied phase corrections or the phase alignment is unknown", so such a record gives no correction and declares the alignment of the constellation's signals no other record covers unknown.correction_cycles- the correction in cycles, ornilwhere the record leaves the field blank ("Correction applied (cycles) or blank if none"). A blank correction is not read as0.0here; the phase rows ofSidereon.GNSS.RINEX.Observations.phases/3state what correction applies.satellites- the satellites the record names. An empty list, with nounrepresentable_satelliteseither, means every satellite of the system and code.unrepresentable_satellites- satellites the record names by a well-formed designator no satellite id holds, such as"R28", as written. No observation of theirs is kept, so the correction applies to none of them; they are kept so the record is written back whole.