The spaced antenna method for VHF/UHF radar applications is discussed for the general observational configurations including the off-zenith observational mode. On the basis of the assumptions of "locally frozen-in" and volume scattering a physical model is constructed. Cross-correlation and autocorrelation functions are derived and applied for the discussion of the various aspects of the full correlation analysis. Spectral width, aspect sensitivity, and characteristic length are compared for different echo mechanisms in this paper. Some observational results based on the model predictions will be discussed.