FIG Peer Review Journal


Structures Monitoring Using GNSS Technology and Sequential Filtering (7540)

Stefano Gandolfi, Luca Poluzzi and Luca Tavasci (Italy)
Dr. Stefano Gandolfi
Scool of Enginering and Architecture
University of Bologna
Viale Risorgimento 2
Corresponding author Dr. Stefano Gandolfi (email: stefano.gandolfi[at], tel.: +390512093102)

[ abstract ] [ paper ] [ handouts ]

Published on the web 2015-03-31
Received 2014-10-20 / Accepted 2015-02-07
This paper is one of selection of papers published for the FIG Working Week 2015 in Sofia, Bulgaria and has undergone the FIG Peer Review Process.

FIG Working Week 2015
ISBN 978-87-92853-35-6 ISSN 2307-4086


The GNSS technology is still not considered as a suitable method for the structures monitoring because of the relatively low precision, despite the increasing of the acquisition frequencies. This paper concern the evaluation of a strategy to filter a daily kinematic GNSS solution using a smoothing model of movement based on the observation of the previous days, so obtaining a less scattered solution. A test was made with a GNSS permanent station located on top of the troubled Garisenda tower in Bologna (Italy), being it an important cultural heritage and a reliable test site. Because of the presence of the nearby Asinelli tower, taller of the Garisenda, the sky visibility here is not optimal and for that reason a particular sequential filtering can be adopted in order to obtain more accurate solutions. The test was performed by using the RTKLIB software to calculate 1 Hz baselines between the test station and a master one located about one km far from the tower and on a stable area. In order to obtain reliable results some variables were considered both in the data processing phase and in the filter definition. All these results are reported and discussed in detail into the paper. The test results are evidencing a scattering reduction in the filtered kinematic time series of about the 20%, especially on the weaker geodetic components.
Keywords: GNSS/GPS; Engineering survey; kinematic positioning; RTKLIB; structure monitoring; Garisenda tower; sequential filtering