PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/21-12:27:40
G02     62.6           29.3                2.0 +/-    1.16       3.5 +/-    1.16  0.020 / 0.030
G05     55.4           59.3                2.5 +/-    0.48       2.9 +/-    0.48  0.030 / 0.030
G12     185.9          31.4                3.4 +/-    1.80       5.9 +/-    1.80  0.070 / 0.070
G13     127.5          16.7                4.1 +/-    2.14       9.8 +/-    2.14  0.080 / 0.100
G15     161.3          14.5                2.6 +/-    1.12       6.5 +/-    1.12  0.030 / 0.040
G20     210.8          59.6                5.1 +/-    0.59       5.8 +/-    0.59  0.040 / 0.050
G21     275.0          23.1                3.3 +/-    1.04       6.8 +/-    1.04  0.070 / 0.080
G25     233.4          50.1                6.0 +/-    2.69       7.6 +/-    2.69  0.060 / 0.080
G29     333.5          60.5                1.3 +/-    0.30       1.4 +/-    0.30  0.130 / 0.340