Application of IGR Extrapolated Orbit in Real-Time Tropospheric Monitoring

Based on the theory of precise orbit determination and orbit extrapolation,the differences between IGS rapid orbit(IGR)extrapolated one day orbits and IGS final orbits is analyzed.And using these two kinds of orbits,the ZWDs of some European IGS/TAI stations,such as BRUS,IENG,PTBB,NPLD,WAB2 etc.are estimated and compared.The difference of the orbits shows that except the problem satellites(such as manoeuvre,modelling,bad phase or/and bad code data satellies),all the other satellites,including healthy satellites and ill satellites,have IGR extrapolated one day orbits with an accuracy better than 0.5 m in radial-axis.The comparison of the ZWDs shows that excluding the problem and ill satellites',using the IGR extrapolated one day orbits,a negligible bias and an RMS less than 5 mm can be obtained wrt IGS final orbits.The IGR extrapolated one day orbits has the potential in real-time tropospheric monitoring applications.