Comparison between leveling-gps heights and Italian gravimetric Geoid

Abstract

The recent development of the Global Positioning System geodetic technique allow the determination of the separation between the ellipsoid and the geoid if GPS-derived elevations are compared with spirit leveling measurements; this approach may provide a contribution to the definition of the geoidal ondulation even on areas such as the Italian peninsula characterized by wide roughness of topography and very complex geological and structural features. With this aim in 1993 we measured by the GPS technique the position of 32 benchmarks along some of the Italian first order leveling routes located across the Apenninic chain. The simultaneous surveys performed on ITRF stations and on 5 tide gauge stations, may provide an accurate constrain of the gravimetric geoid recently computed by DIIAR in Milan, Italy.