For the small angle scattering of coherent plane waves from inhomogeneous random media, the three‐dimensional mean square distribution of random fluctuations may be recovered from the interferometric detection of the nonstationary modulational structure of the scattered field. Modulational properties of coherent waves scattered from random media are related to nonlocal correlations in the double sideband structure of the scattered field. To second order, such correlations may be expressed in terms of a suitably generalized spectral coherence function for analytic fields.