Local monitoring by low cost devices and free and open sources softwares

The purpose of local monitoring is to closely model displacements, evolution and deformations of civil engineering structures and model local phenomena like landslides. For certain applications, latency of the monitoring results is not a crucial point. In other cases a small latency is fundamental: for example, a suspected Alpine landslide that insists on villages. In these cases, contiunous quasi real time monitoring by permanent stations is required. Here, a typical monitoring configuration is given by a GNSS reference permanent station, outside the monitored area, in a stable site and several permanent stations in the monitored area. Data can be processed and the results can be monitored in a quasi continuous way by automated procedures. In these situations, the use of low cost GNSS receivers could be interesting because it can significantly increase the number of monitored points without notably increasing the network cost. This investigation is the scope of our work and several experiments have been set up and performed to assess them. To reach our goals, geodetic and low cost receivers are teamed up: Leica GR10 as reference station and several single frequency u-blox 7P receivers. Once the aquisition phase is completed data are processed with commercial (Leica GeoOffice), academic (Bernese) and free and open source softwares (goGPS and RTKLIB). The results are compared in the final step of the project, accuracy and reliability of solutions are discussed. Their results will be described in the presentation and the full paper.