PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/02/20-08:13:10
G02     61.2           30.3                2.9 +/-    0.96       5.0 +/-    0.96  0.060 / 0.050
G05     56.7           59.5                3.7 +/-    0.69       4.2 +/-    0.69  0.040 / 0.050
G12     186.0          33.3                5.3 +/-    1.20       8.7 +/-    1.20  0.080 / 0.220
G13     128.6          15.4                7.0 +/-    1.76      17.2 +/-    1.76  0.150 / 0.230
G15     162.3          13.1                4.5 +/-    1.54      11.7 +/-    1.54  0.020 / 0.040
G20     211.0          54.6                6.5 +/-    0.68       7.8 +/-    0.68  0.020 / 0.040
G21     272.3          19.3                4.0 +/-    2.48       8.9 +/-    2.48  0.040 / 0.090
G25     237.5          51.7                5.2 +/-    1.28       6.4 +/-    1.28  0.030 / 0.090
G29     329.7          56.3                2.6 +/-    0.84       3.0 +/-    0.84  0.030 / 0.070