PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2018/04/20-08:27:40
G10     305.4          54.2                3.9 +/-    0.91       4.7 +/-    0.91  0.100 / 0.790
G14     212.5          13.5                4.6 +/-    2.02      12.0 +/-    2.02  0.110 / 0.710
G15     45.5           22.7                1.3 +/-    1.07       2.6 +/-    1.07  0.050 / 0.090
G20     60.2           41.3                4.0 +/-    0.76       5.8 +/-    0.76  0.060 / 0.090
G21     111.7          70.2                3.4 +/-    0.74       3.6 +/-    0.74  0.090 / 0.140
G24     91.5           28.3                3.1 +/-    0.97       5.7 +/-    0.97  0.070 / 0.150
G27     293.5          36.5                4.6 +/-    1.80       7.0 +/-    1.80  0.040 / 0.080
G32     213.0          39.0                5.0 +/-    0.80       7.4 +/-    0.80  0.040 / 0.080