PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/07/20-17:57:30
G02     201.9948       18.9010         16.8180 +/-  0.9146   38.0143 +/-  0.9146  0.080 / 0.500
G06     169.0343       56.8699         16.5449 +/-  0.7348   19.3432 +/-  0.7348  0.120 / 0.480
G13     227.1028       11.7483         12.8086 +/-  4.5466   34.3935 +/-  4.5466  0.040 / 0.040
G17     27.8941        55.9737         11.9020 +/-  0.7081   14.0399 +/-  0.7081  0.030 / 0.050
G19     338.1463       70.4567         13.2900 +/-  0.6227   14.0132 +/-  0.6227  0.070 / 0.150
G24     309.8312       29.8283         11.1113 +/-  1.8645   19.5280 +/-  1.8645  0.070 / 0.120
G28     90.8577        38.2905         13.7971 +/-  0.5751   20.6490 +/-  0.5751  0.090 / 0.320
G30     158.0094       14.6168         16.1209 +/-  4.9413   40.4719 +/-  4.9413  0.110 / 0.300