[en] Wave reflections from density fluctuations with magnitudes and frequencies typical of drift waves have been investigated. Both drift waves and the reflected phase and amplitude depend on the density gradient scale length, and this common feature implies that both the angular deviation of a normally propagating wave and the phase change on reflection are of order unity. Thus the surface will always appear ''rough'' and amplitude variations will always be large. For smaller amplitude waves numerical solutions of the one dimensional full wave equation for the propagation near cutoff frequencies has been used to show how to interpret reflectometry measurements. For density perturbations with wavelengths near the density scale length, the external fluctuating phase can be simply interpreted in terms of a fluctuating density near the cutoff layer. However, the amplitude of the phase response falls substantially as the fluctuation wavelength, Λ, approaches the free space wavelength of the reflected wave, λ_o, and the location of the maximum response moves out in front of the cutoff layer following the wave matching condition k_Λ = 2k ∼ 2η(x)k₀. Similarly, correlation measurements of density fluctuations from probe waves of different wavelengths are shown to be limited to about four times the average reflected wavelength. 12 refs., 9 figs