In detailed studies, the directional reflectance properties of astronomical bodies are often expressed in terms of the five Hapke parameters which semi-empirically describe the variation of albedo with phase angle, including a characterization of the opposition effect of regolith surfaces.
ɪn diːtˈeɪld stˈʌdiz, ðə dᵻɹˈɛkʃənəl ɹᵻflˈɛktəns pɹˈɑːpɚɾiz ʌv ɐstɹənˈɑːmɪkəl bˈɑːdiz ɑːɹ ˈɔfən ɛkspɹˈɛst ɪn tˈɜːmz ʌvðə fˈaɪv hˈæpk pɚɹˈæmɪɾɚz wˌɪtʃ sˈɛmaɪɛmpˈɪɹɪkli dᵻskɹˈaɪb ðə vˌɛɹɪˈeɪʃən ʌv ælbˈiːdoʊ wɪð fˈeɪz ˈæŋɡəl, ɪŋklˈuːdɪŋ ɐ kˌæɹɪktɚɹaɪzˈeɪʃən ʌvðɪ ˌɑːpəzˈɪʃən ɪfˈɛkt ʌv ɹᵻɡˈɑːlɪθ sˈɜːfɪsᵻz.