Three-year solution of EOP by combination of results of different space techniques

The method of non-regular combination of results of different techniques, namely GPS, VLBI, SLR and Doris, to obtain unique values for both the Earth orientation parameters (EOP) and the station coordinates needs the EOP at the adjacent epochs to be suitably constrained to each other. Modified smoothing algorithm was used as this constraint. Weighting controls smoothness of the com- bined EOP, so that it can also be used to filter out undesirable frequencies from the solution. To do it, a transfer function was empirically estimated from two combinations of EOP and used to compute three-year solution. The result is compared with IERS c04 series and presented here.