PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/20-06:58:00
G01     41.2           16.2                2.2 +/-    1.26       5.3 +/-    1.26  0.040 / 0.110
G06     179.4          34.8                6.9 +/-    1.68      10.9 +/-    1.68  0.040 / 0.100
G13     238.8          22.0                3.5 +/-    4.00       7.3 +/-    4.00  0.150 / 0.150
G15     270.2          12.5                4.7 +/-    2.32      12.5 +/-    2.32  0.160 / 0.190
G17     3.9            69.8                4.7 +/-    0.56       5.0 +/-    0.56  0.090 / 0.250
G19     281.1          70.1                4.4 +/-    0.81       4.7 +/-    0.81  0.110 / 0.270
G24     317.0          18.3                2.6 +/-    1.44       6.1 +/-    1.44  0.020 / 0.030
G28     72.6           46.2                4.1 +/-    0.85       5.5 +/-    0.85  0.050 / 0.040
G30     154.0          25.7                6.9 +/-    0.73      13.3 +/-    0.73  0.060 / 0.090