Distribution patterns of the R945/R745 values against reflectance at 745 nm. Panels ato d show the results for the CMOS-bin1, CMOS-bin2, CMOS-bin4, and CMOS-whole datasets, respectively. The squares represent the CMOS data and the circles represent the LSCC samples. Each square in these subfigures is the mean value within a 1° phase angle bin. The spectra of the Apollo returned lunar soil samples are from the LSCC database and are measured under the standard geometry (i = 30°, e = 0°, g = 30°). The I_s /FeO values are from Pieters et al. (2006).