Measured ionospheric distortion of HF ground-backscatter spectra

Skywave-radar measurements of backscatter from land are used to estimate some statistical properties of the ionospheric distortion encountered by sea-state radars. We confirm that samples of the path spectrumP(omega)are normally distributed and uncorrelated in frequency, and we estimate the first two moments ofP(omega)and their spatial and temporal correlation, for quiet F-layer daytime propagation. An empirical relation connects the equivalent width ofP(omega)and expected errors in estimating ocean wave height.