PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/20-19:42:50
G01     121.0          16.5               15.9 +/-    1.54      38.0 +/-    1.54  0.110 / 0.200
G07     73.7           67.9               13.2 +/-    0.71      14.1 +/-    0.71  0.090 / 0.230
G08     47.3           37.0               10.3 +/-    0.80      15.8 +/-    0.80  0.100 / 0.260
G09     177.8          28.8               15.9 +/-    2.64      28.5 +/-    2.64  0.110 / 0.250
G11     111.7          38.9               15.3 +/-    0.62      22.7 +/-    0.62  0.030 / 0.040
G13     318.8          17.3                9.5 +/-    1.65      22.2 +/-    1.65  0.030 / 0.040
G17     202.6          18.2               19.4 +/-    2.74      44.7 +/-    2.74  0.050 / 0.100
G18     97.1           20.0               12.7 +/-    1.02      28.0 +/-    1.02  0.050 / 0.110
G28     289.4          56.7               14.7 +/-    0.72      17.2 +/-    0.72  0.050 / 0.060
G30     346.8          68.1               11.4 +/-    1.17      12.2 +/-    1.17  0.040 / 0.070