Performance of low-cost GNSS receiver for landslides monitoring: test and results

Italy is deeply afflicted by geo-hydrological risk, where a predominant part of its area is under risk.Recently, advanced research and sensors have played an important role in realizing automatic systems for landslide monitoring and to alerting. The cost of these systems, considering all parts, limits their use and the cost of each sensor influences the investment. Geodetic global navigation satellite system (GNSS) receivers, which are commonly used to realize these activities, are an appropriate example; however, their costs are quite high.The aim of this research was to test the actual performance of a mass-market GNSS receiver, with the purpose of verifying if such type of sensors can be used for landslide monitoring. In particular, the benefits due to the coupling between mass-market receivers and products offered by a network of GNSS permanent stations (e.g. Virtual RINEX) have been investigated.To verify the capability of these sensors to detect a deformation, under the minimum deformation detectable point of view, a special slide was built, in order to conduct a dedicated test. The support was moved both in horizontal and vertical directions with high precision, with purpose to detect correctly a three-dimensional movement.Tests were carried out considering the dependence of some factors: the most important are the acquisition time and the distance from the GNSS reference station. Interesting is the use of virtual reference station based on GNSS network, as a reference station: the performance achieved using Virtual RINEX for the control of movements and deformations are analysed. The accuracy and precision of movement determination were evaluated and compared, for each test, considering the different factors. The tests and results are described in this contribution.