PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/11/21-13:27:40
G02     40.0           49.6                4.9 +/-    1.32       6.3 +/-    1.32  0.030 / 0.020
G05     129.6          66.5                8.5 +/-    0.41       9.2 +/-    0.41  0.020 / 0.020
G06     56.2           14.9                5.0 +/-    2.30      12.4 +/-    2.30  0.080 / 0.120
G12     196.2          62.0                7.8 +/-    0.80       8.7 +/-    0.80  0.090 / 0.130
G20     200.1          31.1                5.4 +/-    1.99       9.2 +/-    1.99  0.030 / 0.030
G25     285.5          57.2                9.4 +/-    3.95      11.0 +/-    3.95  0.030 / 0.030
G29     314.5          37.3                3.8 +/-    0.96       5.9 +/-    0.96  0.040 / 0.040