Analogous to conventional sensors, a sensor characteristic curve is required to derive strain values from the raw measurement quantity (e.g. wavelength, frequency or intensity of backscattered signal). Nevertheless, manufactu. Analogous to conventional sensors, a sensor characteristic curve is required to derive strain values from the raw measurement quantity (e.g. wavelength, frequency or intensity of backscattered signal). Nevertheless, manufacturers of fiber optic sensing cables often do not provide their own calibration parameters and refer to literature values inste. The basic principle of DFOS systems (Fig. 1a) is based on natural scattering of an optical pulse during the forward propagation along the sensing fiber. Small parts of the scattered light are reflected back to the interrogation unit and can be used there for sensing purposes. As depicted in Fig. 1 (b), the backscattering spectrum can be split into. Due to harsh environments on site, robust sensing cables are required to ensure the integrity of the sensing fiber during the driving process. For that reason, IGMS normally uses prefabricated sensing cables from Solifos AG (Switzerland) to measure strain along the piles. Figure 2 shows the setup of two cable types [27, 28], which are especially de.
