“…If a number of these locations are predetermined, which makes the system more effective, the sensor array is called a quasidistributed fibre optic sensor (QDFOS), as illustrated in figure 5(a). In this type of sensor network, the reflectors can be created through fusion splices [109,118], pathlength differences [40,46,51,96,109] or FBGs with known reflectance wavelengths [5,61,62,65,68,106]. Moreover, the individual sensors within a network can be arranged in either series topology [108] (see figure 5(a)), parallel topology [22] as illustrated in figure 5(b) or a combination of both [23,118] as illustrated in figure 5(c).…”