  Inspired by the concept of coherent frozen waves, this paper introduces one
possible theoretical framework of its partially coherent version, a frozen
spatial coherence, in which a desired two-point correlation structure of an
optical field is created on the propagation axis by superposing partially
coherent zero-order Bessel beams. It is shown that the cross-spectral density
can be given a description in terms of a two-dimensional Fourier series,
analogous to the one-dimensional approach of coherent frozen waves. The
formalism is applied to the design of a partially coherent field which is
highly coherent only if the pair of points in the propagation axis belong to a
predetermined and finite range and highly incoherent outside that range.
