PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/20-08:57:40
G02     217.5          64.4                4.8 +/-    0.98       5.3 +/-    0.98  0.120 / 0.440
G06     60.1           78.7                1.3 +/-    0.73       1.4 +/-    0.73  0.140 / 0.380
G12     319.0          36.7                1.7 +/-    1.72       2.5 +/-    1.72  0.070 / 0.080
G17     60.1           30.2                2.7 +/-    0.99       4.8 +/-    0.99  0.060 / 0.090
G19     43.6           46.6                2.2 +/-    0.41       2.9 +/-    0.41  0.030 / 0.090
G24     264.0          40.8                5.0 +/-    0.78       7.2 +/-    0.78  0.030 / 0.070
G28     124.6          11.1                4.8 +/-    2.25      13.0 +/-    2.25  0.040 / 0.080