PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/20-17:27:30
G07     307.3          46.4               11.8 +/-    0.99      15.5 +/-    0.99  0.050 / 0.090
G08     132.0          40.4               12.7 +/-    1.11      18.3 +/-    1.11  0.050 / 0.090
G09     301.4          78.7               11.3 +/-    1.07      11.5 +/-    1.07  0.030 / 0.060
G16     42.1           22.4                8.6 +/-    0.89      17.8 +/-    0.89  0.030 / 0.060
G23     143.7          58.0               11.2 +/-    0.68      12.9 +/-    0.68  0.040 / 0.080
G27     77.6           37.1               10.0 +/-    0.54      15.2 +/-    0.54  0.060 / 0.060
G28     224.6          13.6               14.5 +/-    2.91      37.3 +/-    2.91  0.090 / 0.260
G30     287.2          23.9               10.0 +/-    1.15      20.1 +/-    1.15  0.090 / 0.250