Multi-GNSS implementation and assessment of the phase residual method for structures dynamic load and natural frequency estimation

Continuous monitoring of the dynamic displacement of bridges is usually accomplished with the use of traditional displacement measurement dedicated equipment, such as accelerometers and displacement transducers. During the past decade, following the increase in quality of GNSS equipment, new methodologies were developed to provide equivalent types of measurements at a lower cost. One of these methods is the phase residuals method (PRM), where the phase residuals from a relative static GPS positioning are assessed in the frequency domain. This paper investigates the limitations imposed to the method and how the use of modernized GNSS signals may improve the reach of applications of the PRM. This study concludes that the multipath frequency influence in the power spectrum is less prominent in modernized GNSS signals, thus, extending the reach of the method for sub-Hz natural and displacement frequencies estimation.