(a) Correlation coefficient between gamma ray (GR) log data and Poisson impedance (PI) values with different c values. (b) Crossplot between the estimated lithology impedance (LI) and shale volume. (c) Joint histogram of the estimated LI and shale volume. (d) Correlation coefficient between effective porosity-log data and PI values with different c values. (e) Crossplot between the estimated porosity impedance (⁠|$\phi {\rm{I}}$|⁠) and porosity. (f) Joint histogram of the estimated |$\phi {\rm{I}}$| and porosity. (g) Correlation coefficient between resistivity-log data and PI values with different c values. (h) Crossplot between the estimated fluid impedance (FI) and resistivity. (i) Joint histogram of the estimated FI and resistivity.