PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/20-06:57:50
G01     41.2           16.2                2.2 +/-    2.13       5.3 +/-    2.13  0.070 / 0.070
G06     179.4          34.8                5.8 +/-    1.80       9.2 +/-    1.80  0.060 / 0.050
G13     238.8          22.0                3.7 +/-    2.38       7.8 +/-    2.38  0.030 / 0.020
G15     270.2          12.5                2.7 +/-    1.78       7.2 +/-    1.78  0.030 / 0.020
G17     3.9            69.8                4.4 +/-    0.41       4.7 +/-    0.41  0.180 / 0.220
G19     281.1          70.1                4.0 +/-    0.64       4.2 +/-    0.64  0.160 / 0.220
G24     317.0          18.3                2.2 +/-    2.13       5.0 +/-    2.13  0.060 / 0.080
G28     72.6           46.2                4.5 +/-    1.18       6.0 +/-    1.18  0.060 / 0.080
G30     154.0          25.7                5.7 +/-    1.65      10.9 +/-    1.65  0.120 / 0.140