PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/05/20-16:57:40
G07     17.2           68.4                8.4 +/-    0.67       9.0 +/-    0.67  0.030 / 0.040
G08     64.0           49.3                9.4 +/-    0.44      12.0 +/-    0.44  0.030 / 0.040
G09     179.7          48.6               12.7 +/-    2.26      16.3 +/-    2.26  0.040 / 0.060
G11     130.2          27.9               12.5 +/-    0.83      23.0 +/-    0.83  0.050 / 0.050
G18     114.2          10.7                1.5 +/-   31.14       4.1 +/-   31.14  0.050 / 0.060
G23     158.7          14.8               12.5 +/-    2.30      31.3 +/-    2.30  0.040 / 0.050
G27     40.0           16.1                8.2 +/-    1.12      19.8 +/-    1.12  0.040 / 0.090
G28     260.4          46.3               12.5 +/-    0.87      16.6 +/-    0.87  0.050 / 0.080
G30     321.9          52.0               11.2 +/-    0.68      13.8 +/-    0.68  0.110 / 0.190