6 Discussion

It must be pointed out that, in our case, we estimated the equator correction and $\Delta\delta$ corrections for the declination zone (mostly north hemisphere) of the ASPHO observations ($-2^{\rm o} \leq \delta \leq 88^{\rm o}$).

In a near future we will reduce all the data taking into account the IERS system utilizing the $\Delta\phi$ and $\Delta t$ given by the IERS and the $\Delta R$ given by the group observations. We expect to obtain results not so different from these ones but with a better precision.