Monitoring system using low cost GNSS sensors: first experiments and performance evaluation

This work aims to assess the possibility to use a low cost GNSS instrumentation for structural monitoring purposes. Under the assumption that about one centimeter can be the magnitude of the displacements that we aim to detect, several instrumentations were compared at different baseline distances. All the tests have been performed considering one week of observations. Different observing session time spans have been considered, ranging from 1 hour to 24 hours. Tests demonstrate that by using a single frequency receiver is not possible to achieve the requested precision for baselines longer than a km, at least if observing sessions shorter than 6 hours are needed. Nevertheless, for a baseline within a hundred meters is possible to achieve effective precisions by using a couple of low cost stations also for observing sessions of one hour. The only configuration which does not respect such performances is the one using the default "patch" antennas that we discourage for precision purposes.