Parse Rinex 3 files with blank SYS / PHASE SHIFT header lines
Rinex 3 files with blank header lines for SYS / PHASE SHIFT and fail to parse. One such example is GANP00SVK_R_20151890000_01D_30S_MO.crx.gz where the SYS / PHASE SHIFT line for SBAS at line 31 (line 29 when Hatanaka compression has been removed) reads:
S SYS / PHASE SHIFT
whereas a non-blank line for Galileo reads:
E L5X 0.00000 SYS / PHASE SHIFT
The faulty line display neither an observation type nor a phase shift value. This seems to be an application of one sentence in section 9.1 in Rinex 3.03 specification.
The uncorrected reference signal group of observations are left blank in the SYS / PHASE SHIFT records.