PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/21-09:12:40
G02     229.4          72.9                3.8 +/-    0.57       3.9 +/-    0.57  0.160 / 0.320
G05     174.1          11.4               -3.0 +/-   11.59      -8.1 +/-   11.59  0.210 / 0.350
G06     43.0           70.1                2.8 +/-    0.38       2.9 +/-    0.38  0.040 / 0.050
G12     320.8          44.9                3.3 +/-    0.39       4.4 +/-    0.39  0.040 / 0.050
G17     67.2           24.9                3.9 +/-    0.74       7.5 +/-    0.74  0.070 / 0.100
G19     52.9           41.1                2.3 +/-    0.72       3.3 +/-    0.72  0.050 / 0.090
G24     252.9          37.7                3.0 +/-    2.60       4.6 +/-    2.60  0.030 / 0.020