Abstract
Precise lunar phase functions are necessary for a compositional analysis of Clementine UV-VIS images. Phase functions are considered to have both wavelength dependence and geological-type dependence. The lunar reflectance spectrum has been successfully clustered in to 9 spectral groups by applying Self-Organizing Map (SOM) method in three wavelengths, 415nm, 750nm, 950nm (Yokota 2002). The validity of the clusters were shown by comparing the results with the spectral unit map of USGS and the compositional distribution obtained by Lunar Prospector. Yokota (2002) developed a method of determining the phase functions precisely by selecting pairs of observation data that observe the same surface but has a different phase angle, And obtainded the phase functions for each spectral group.
We have made several lunar regolith samples that correspond to each spectral group. Then, we measured the reflectance spectra and obtained the phase functions for each sample. We will compare the results with the previous works and examine what factors control the phase functions.
