The 68-cm radar echoes from the moon are interpreted with the approximation that the scattering can be described by the laws of geometric optics. The treatment relates the observed angular power spectrum directly with the distribution of surface normals, and no assumed functional dependence of the surface correlation function is required. A simple calculation gives a dielectric constant of 2.6 to 2.8, an average slope of 11 ø to 14 ø, and an rms slope of 15 ø to 23 ø. The depolarization data and the contour of the angular power spectrum are used in selecting these values from the different possible sets. The reduction technique has the added feature that the derived formulas can be used directly to calculate the microwave emissivity as a function of both angle and polarization.

We recently used a geometric optics model to interpret the 68‐cm radar echoes from the moon [Rea et al., 1964]. The angular power spectrum of the radar return was directly related to the distribution function of the surface normals. This in turn was used to calculate the average and rms slopes and the average and rms normals, parameters which can be used to characterize the surface roughness. A comparison of our numbers with those found by other workers using physical optics approaches revealed ours to be somewhat higher than anticipated.

No abstract

No abstract

No abstract