PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/21-18:39:40
G08     270.0          18.9               70.9 +/-    0.73     160.4 +/-    0.73  0.040 / 0.070
G10     55.7           59.8              133.0 +/-    0.29     151.3 +/-    0.29  0.050 / 0.080
G11     313.6          15.0               53.2 +/-    1.83     132.3 +/-    1.83  0.250 / 0.230
G14     262.1          64.8              116.6 +/-    0.57     127.5 +/-    0.57  0.120 / 0.250
G18     90.6           36.2               79.9 +/-    0.62     124.1 +/-    0.62  0.080 / 0.100
G21     152.7          12.9               50.2 +/-    2.62     131.4 +/-    2.62  0.080 / 0.090