Improved KLT Algorithm for High-Precision Wavelength Tracking of Optical Fiber Bragg Grating Sensors

Figure 4

Comparison of different eigenvalue tracking approaches, in small FBG wavelength shift: after applying (9)–(14) for different values of wavelength shift within ±1 pm, in different SNR conditions (50 dB and 60 dB), the chart displays the highest rank eigenvalue (with ) on (b) and the second-rank eigenvalue on (a). In both cases, eigenvalues have been normalized by the eigenvalue obtained in reference conditions ( pm).

(a)

(b)