Replication Data for: Detection of Low-Frequency Displacements on a Wooden Footbridge Using Dual Total Stations and Time-Series Alignment

This study investigates whether two total stations can be effectively used together to monitor small movements of a pedestrian footbridge and to better understand how the structure responds under pedestrian loading. The purpose was to test if a dual-station setup can detect consistent displacement patterns at corresponding points, whether time-alignment methods improve data interpretation, and to what extent sub-millimeter displacements can be measured using non-robotic instruments. Two different station configurations were applied: one in which the instruments observed corresponding points from opposite sides of the bridge, and another in which they observed different points from the same side. Measurements were carried out over two consecutive days during five pedestrian flow campaigns, with displacements tracked in longitudinal, transverse, and vertical directions. To address timing differences in the manually collected data, Dynamic Time Warping was used to align the measurement series and allow direct comparison between instruments. The results show that the dual-station setup can reliably capture coherent patterns of bridge motion, particularly when observing corresponding points from the same-side configuration. Time-warping methods greatly improved the interpretability of asynchronous series, revealing stronger and more consistent correlations between stations. While the same-side configuration provided the most stable and interpretable results across all directions of displacement, the opposite-side configuration also produced useful but more variable agreement, especially in the transverse direction, where local torsional effects were present. Importantly, the findings demonstrate that sub-millimeter displacements can be resolved whenthe setup geometry is favorable, references are stable, and alignment procedures are applied. Overall, this study confirms that a dual-station total station approach offers a practical and precise tool for structural health monitoring of pedestrian bridges.