Combination Strategy for the Geocentric Realization of Regional Epoch Reference Frames

For high-resolution regional geodetic applications, the International Terrestrial Reference Frame (ITRF) is complemented by densifications. These are realized either as multi-year solutions related to a tectonic plate (e.g., EUREF for Europe) or epoch reference frames (ERFs) capture non-linear geophysical station motions caused by, e.g., earthquakes non-tidal loading SIRGAS Latin America). GNSS-only-based have in common that their datum aligned with ITRF at specific epoch. The consequence origin represents Earth’s center of figure and does not coincide instantaneous mass. Here, we present studies on direct geocentric realization ERFs. We propose realize each combining global GNSS, SLR, VLBI networks via measured local ties co-located sites. A uniformly distributed GNSS network used orientation no-net-rotation constraint respect densified stations subnetwork. developed combination filtering strategy aims guarantee stable epoch-wise solution. Validating our results against models relating centers mass figure, show displacement time series reflect seasonal processes. As approach need rely co-location sites region interest, it conceptually transferable other regions globe.