Integrating GPS with national networks by collocation method

In the integration of geodetic networks with different geodetic coordinate systems, the similarity transformation seems to be the most suitable method because the geodetic coordinate systems are designated to be Cartesian (orthogonal). However, this method may always not be practical to use in most surveying works demanding such high accuracies as the coordinates used in the transformation are distorted. In this case, methods alternative to well-known similarity transformations can be considered for the integration of geodetic networks with other systems. However, in this paper, the collocation method is introduced into the similarity transformation instead of applying an alternative method. Thus, not only can more appropriate transformation parameters be easily computed, but also the distortions in coordinates can be modeled. For this purpose a case study employing this strategy is also included and its results are analyzed and interpreted.