PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/07/21-15:57:40
G01     74.3           32.9                9.6 +/-    0.65      15.9 +/-    0.65  0.090 / 0.140
G07     135.3          30.3                9.3 +/-    2.72      16.1 +/-    2.72  0.090 / 0.120
G11     54.8           29.9                8.3 +/-    1.78      14.5 +/-    1.78  0.080 / 0.160
G13     280.9          37.0               11.5 +/-    1.27      17.7 +/-    1.27  0.070 / 0.170
G15     308.7          12.7                9.4 +/-    1.37      24.7 +/-    1.37  0.040 / 0.040
G17     228.9          68.8               11.2 +/-    0.94      11.9 +/-    0.94  0.040 / 0.040
G19     221.9          41.1               13.0 +/-    2.29      18.5 +/-    2.29  0.130 / 0.230
G28     13.7           59.9                9.4 +/-    0.62      10.7 +/-    0.62  0.130 / 0.220
G30     129.8          67.6                8.0 +/-    0.37       8.5 +/-    0.37  0.030 / 0.040