Radar backscatter from bare sandstones, shales and limestones was measured in May 1982 in the Monument Upwarp region of south-eastern Utah using a helicopter-borne 4-4-17-6 GHz multipolarization radar scatterometer. Rock samples for laboratory analysis were collected and surface conditions described. The purpose of the experiment was to observe the backscatter from selected rock formations as a function of incidence angle, frequency and polarization to determine the degree of correlation with the permittivity and roughness of the rocks. An additional goal was to measure the permittivity of the rock samples using free space, waveguide and in situ methods. The permittivity of the sandstone ranged from 3·0 to 3·75, the shales from 4·2 to 5·0, and the limestones from 7·5 to 8·5. Multiple linear regression analysis of the data indicated a high (greater than 90 per cent) correlation between the radar backscatter and the permittivity of the rocks
