Transformation from ITRF2000 to WGS84 – A Case Study for Iranian Permanent GPS Network, IPGN

Last part of the first step was calculating the whole IPGN network coordinates in WGS84 by the estimated parameters. Second step in this problem was selecting some other stations to control the estimated parameters, so we select 9 stations in different part of the country according to table 1and then transfer these coordinates with estimated parameters. See the result in fig7 and table one.

Figure 7: Residuals of selected stations in second step

Table 1: Selected stations in second step

Figure 8: Residuals of all stations in X component

Figure 9: Residuals of all stations in Y component

Figure10: Residuals of all stations in Z component

Conclusion
As it is obvious in these charts the obtained parameters have acceptable results in three dimensions with residuals better than ±0.05 m in most stations in X and Y direction. As far as can be seen in the Z direction chart, the magnitude of residuals are extremely small and can say that it is ignorable. The last step done, was to compare 6 parameters with 7 parameters model in order to see whether by omitting scale from 7-parameter, the whole results will change or not. But no considerable difference was seen so in order to keep standard form of parameters, 7 parameters presented as final transformation parameters between ITRF2000 and WGS84 in Iran region. .