Performance of videogrammetric displacement monitoring technique under varying ambient temperature

There has been an increasing number of attempts to apply videogrammetric technique to displacement measurement of civil engineering structures. Its potentials in structural health monitoring have also gained more attention. This study carried out an investigation on the effect of temperature variation on the measurement accuracy of videogrammetric technique in an effort to examine its feasibility for structural health monitoring. Long-term indoor videogrammetric measurement tests have been conducted, and the performance of the videogrammetric displacement monitoring technique under ambient temperature conditions has been examined. The results show that temperature variations cause non-negligible errors in measured displacements. In line with the temperature variation, the displacement measurement error also contains not only daily fluctuation pattern but also overall trend. In terms of daily fluctuation pattern, the horizontal measurement error and temperatures of vision measurement system are in satisfac...