(iii) Coherent BOTDA using phase- and polarization-diversity and heterodyne detection and embedded digital signal processing .
He, "Strain dynamic range enlargement of slope-assisted BOTDA by using brillouin phase-gain ratio," Journal of Lightwave Technology, vol.
The temperature profile using BOTDA given in Figure 16(a) cannot resolve the small changes in section A while the large ones in section B are clearly visible.
Caption: Figure 16: Distributed temperature profile near two sections A and B heated, respectively, with small and large temperature changes : (a) BOTDA for profiling in section B and (b) [phi]-OTDR for resolved profiling in section A.
Settings of various parameters of BOTDA in the experiment are shown in Table 6.
Caption: Figure 3: Basic principle diagram of BOTDA.
 carried out an investigation on cable force monitoring by use of the local high-precision FBG sensor in combination with the distributed BOTDA
BOTDA sensors and FBG sensors were assessed during the bolt pull-out experiment.
Based on the BOTDA sensing technology, PPP-BOTDA further improves the accuracy of Brillouin frequency identification that generates a broad bandwidth pulse before a narrow bandwidth one arrives.
And hence the independent temperature compensation is achieved for BOTDA
In this study, the distributed optical fiber sensing technique based on Brillouin Optical Time-Domain Analysis (BOTDA
) was considered to monitor the ground deformation.
interrogator used for the strain measurements implements the setup shown in Figure 1.