Preconditioned Conjugate Gradient Algorithm-Based 2D Waveform Inversion for Shallow-Surface Site Characterization

Table 1

Comparative evaluation of the CG and PCG performances in the checkerboard model noise-free test.

Optimization algorithm	Total iterations	Normalized final misfit value	Initial value of RMSE	Final value of RMSE
CG	40	0.0480	0.2493	0.1535
PCG	40	0.0275	0.2493	0.1169