PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/21-19:27:40
G01     125.0          13.4               19.4 +/-    1.95      50.2 +/-    1.95  0.080 / 0.220
G07     59.4           69.4               16.8 +/-    0.33      17.8 +/-    0.33  0.110 / 0.180
G08     50.5           40.9               13.5 +/-    0.80      19.3 +/-    0.80  0.050 / 0.050
G09     178.4          33.9               17.3 +/-    0.72      28.0 +/-    0.72  0.060 / 0.050
G11     117.4          36.4               17.9 +/-    0.69      27.8 +/-    0.69  0.090 / 0.320
G13     320.5          13.4               11.7 +/-    3.97      30.1 +/-    3.97  0.150 / 0.360
G17     201.8          13.5               21.1 +/-    2.91      54.3 +/-    2.91  0.030 / 0.030
G18     101.9          17.8               15.8 +/-    1.91      36.6 +/-    1.91  0.030 / 0.040
G28     281.0          54.5               15.5 +/-    3.18      18.6 +/-    3.18  0.040 / 0.040
G30     339.1          64.1               16.3 +/-    0.47      17.9 +/-    0.47  0.030 / 0.030