Derived Hapke model parameters of lunar regolith. Panel a: model fits of the phase curves at 480, 570, 750, 1000, and 1580 nm. The open circles show measurements, and the solid circles show the modeled values. Panel b: variation of the single-scattering albedo w with wavelength. Panel c: variation of the phase function parameter b with wavelength. Panel d: variation of the phase function parameter c with wavelength.