  We present an analysis of acoustic daylight imaging in an Earth-like model
assuming a random distribution of noise sources spatially supported in an
annulus located away from the surface. We assume a situation with scalar wave
propagation and that the measurements are of the wave field at the surface.
Then, we obtain a relation between the autocorrelation function of the
measurements and the trace of the scattered field generated by an impulsive
source localized just below the surface. From this relation it is, for example,
clear that the eigenfrequencies can be recovered from the autocorrelation.
Moreover, the complete scattering operator can be extracted under the
additional assumption that the annulus is close to the surface and has a
thickness smaller than the typical wavelength.
