Lateral variations in bulk density and porosity of the upper crust of the Moon
We determined variations in bulk density using most recent GRAIL gravity model GL1500 (Park et al., 2015) together with LOLA derived topography (Smith et al., 2017), both available on the Planetary Data System (https://pds.nasa.gov). Using the estimated bulk densities in combination with grain densities estimated from surface composition, the porosity of the upper crust was determined. Each grid point with a spacing of 0.75 deg was calculated using a circular analysis region of 3 deg radius. The grids are equally sampled following the sample theorem of Driscoll and Healy (1994).