PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/21-06:42:40
G10     251.7          27.4                4.5 +/-    1.34       8.4 +/-    1.34  0.040 / 0.040
G13     52.6           29.5                4.7 +/-    1.74       8.3 +/-    1.74  0.030 / 0.040
G15     82.5           56.7                5.7 +/-    0.54       6.7 +/-    0.54  0.130 / 0.340
G16     294.0          15.4                2.1 +/-    1.82       5.2 +/-    1.82  0.090 / 0.320
G20     350.2          71.2                4.1 +/-    0.47       4.3 +/-    0.47  0.030 / 0.040
G21     335.6          61.3                2.9 +/-    0.41       3.2 +/-    0.41  0.040 / 0.040
G26     265.4          15.1                3.8 +/-    1.14       9.5 +/-    1.14  0.030 / 0.040
G29     165.3          48.5                4.4 +/-    0.55       5.7 +/-    0.55  0.050 / 0.040