Regolith thickness over the lunar nearside: Results from Earth-based 70-cm Arecibo radar observations

► The regolith thickness of four regions over the lunar nearside is inverted. ► A relation among dielectric constant of regolith and its composition is derived. ► A tradeoff relation between lunar surface roughness and buried rocks is derived. ► Regolith thickness of the maria is generally smaller than that of highlands.