Improving GNSS Landslide Monitoring with the Use of Low-Cost MEMS Accelerometers.

Featured Application: Low-cost MEMS (Micro Electro-Mechanical Systems) accelerometers are very interesting sensors with which to monitor land and infrastructure. The synergy between accelerometers and low-cost GNSS (Global Navigation Satellite System) receivers represents both an interesting topic and a highly promising technique for monitoring angular and linear deformations through an integrated approach. Observation and monitoring of landslides and infrastructure is a very important basis for land planning, human activities, and safety. Geomatic techniques for deformation monitoring have usually involved GNSS and total station measurements or, more generally, expensive geodetic instruments, but other techniques, such as SAR (Synthetic Aperture Radar), can be efficiently applied. Using low-cost sensors could be an interesting alternative solution if the accuracy requirements can be satisfied. This paper shows the results obtained for tilt measurements using MEMS accelerometers, which were combined with mass-market GNSS sensors for monitoring five sites located on landslides. The use of a MEMS-like inclinometer requires an important calibration process to remove bias and improve the solution's accuracy. In this paper, we explain the MEMS calibration procedure employed, with a simple and cheap solution. The results indicate that with a simple calibration, it is possible to improve measurement accuracy by one order of magnitude, reaching an angular accuracy of a few hundredths of a degree, verified by an independent technique. [ABSTRACT FROM AUTHOR]