PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/05/21-21:12:20
G02     201.0          26.3               14.5 +/-    1.56      27.5 +/-    1.56  0.070 / 0.130
G06     166.6          60.6               14.4 +/-    0.68      16.3 +/-    0.68  0.080 / 0.120
G17     23.9           58.0               12.1 +/-    0.83      14.0 +/-    0.83  0.050 / 0.090
G19     334.5          69.6               11.7 +/-    0.58      12.3 +/-    0.58  0.050 / 0.080
G24     305.9          33.4               10.5 +/-    1.68      17.1 +/-    1.68  0.040 / 0.040
G28     94.0           36.4               11.7 +/-    0.70      18.1 +/-    0.70  0.030 / 0.040