A levelling network in the PISA plane: a laboratory to test instruments and methods

This work presents an analysis of the results of a GPS measurement campaign carried out in February 2000 in the area of Pisa. The study area has for several years been the object of altimetric surveys both with classic instrumentation and also GPS techniques. The paper analyses the results of the elaboration of the GPS measurements obtained with various programs of elaboration and for one of the latter we examine the effect of the use of precise and broadcast ephemerides. Data from the new GPS reference station installed in Prato (60 km far away the network) have been processed too in order to test its feasibility as master for this subsidence control.