Fig. 5
From: Coda wave interferometry during the heating of deep geothermal reservoir rocks
Comparison of simulated CWI measurements obtained for three different central frequencies (f0 = 200 kHz, f0 = 800 kHz and f0 = 1000 kHz) of the Ricker-shaped source, for which the condition necessary to assume a strong scattering regime is verified. Relative time delays are measured by the “stretching technique” when comparing the waveform recorded at a given temperature with respect to the reference waveform. A linear regression is fitted to the measurements to estimate the slopes s(f0)