PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/21-17:12:40
G07     301.8          43.6               14.9 +/-    0.43      20.5 +/-    0.43  0.050 / 0.090
G08     136.5          36.4               17.4 +/-    0.98      26.9 +/-    0.98  0.040 / 0.090
G09     312.7          74.1               14.7 +/-    0.41      15.3 +/-    0.41  0.040 / 0.040
G16     41.7           26.8               10.1 +/-    2.07      18.9 +/-    2.07  0.040 / 0.040
G23     139.2          63.1               15.5 +/-    1.23      17.2 +/-    1.23  0.120 / 0.140
G27     84.1           36.9               13.2 +/-    0.80      20.2 +/-    0.80  0.120 / 0.200
G30     283.3          20.9               12.6 +/-    1.09      27.1 +/-    1.09  0.050 / 0.070