Feasibility analysis of the performance of low-cost GNSS receivers in monitoring dynamic motion

The development of low-cost GNSS receivers broadens their applications, such as deformation monitoring, which have been performed routinely by survey-grade GNSS receivers. To evaluate the performance of low-cost GNSS receivers, we assessed the precision of low-cost multi-GNSS receivers in monitoring dynamic motion and developed methods of using a closely-spaced dual low-cost GNSS receivers' system to enhance their performance. In this study, both the survey-grade and low-cost GNSS receiver/antennas were mounted on a circular rotating device executing controlled periodic rotation. It was shown that the precision of the low-cost GNSS receivers could be enhanced to the level of 2-4 mm, by using multi-GNSS observations and limiting the noise level based on error modelling and filtering of the closely-spaced low-cost GNSS receivers. Finally, from the experiments and a real bridge monitoring application, it was proved that low-cost GNSS receivers could accurately define modal frequencies of-0.362 Hz and-1.680 Hz, respectively.