Statistical Estimation of Changes in the Dominant Frequencies of Structures in Long Noisy Series of Monitoring Data

Figure 11

SNHT results for pairs of modified data sets from the annual surveys of the Kanellopoulos bridge. Top diagrams: time series of frequency peaks. Bottom diagrams: graph of the 𝑇_𝜈 function, with peaks indicating the location of possible shifts. A horizontal dashed line indicates the 95% level of statistical significance. The gray area in the diagram corresponding to the 2009-2010 test denotes the distance between the point of the shift identified by the SNHT and the point of the real shift.