The first absolute gravity and height reference network in Sicily

The purpose of this work is to explore the methodological and instrumental review for the realization of a new absolute gravity and height reference network in Sicily. The aim of the network is to contribute to the new reference systems in the Italian area, useful for all the scientific and technological activities related to the gravity field and to the proper definition of a modern height system in this region.

The network is composed of 5 stations, evenly distributed forming a large mesh network which roughly covers the entire Sicily. Since four of the five selected stations were measured also in the 1990s, it was also possible to evaluate the long-term behavior (basic requirement for a reference network) of the gravity values at these stations, as well as the ground deformation patterns in the closest GPS/GNSS stations. The observed gravity changes over a time interval of about 30 years at the absolute stations and in the surrounding areas, confirm the stability of the selected areas/sites over the long time.